CRYSTAL GROWTH Interpenetrated Three-Dimensional Networks … · 2014-12-19 · Database. The great interest in the self-assembly of organic molecules into hydrogen-bonded supramolecular

Interpenetrated Three-Dimensional Networks of Hydrogen-BondedOrganic Species: A Systematic Analysis of the Cambridge StructuralDatabase

Igor A. Baburin,† Vladislav A. Blatov,*,† Lucia Carlucci,‡ Gianfranco Ciani,‡ andDavide M. Proserpio*,‡

Samara State UniVersity, Ac. PaVloV St. 1, 443011 Samara, Russia, and Dipartimento di ChimicaStrutturale e Stereochimica Inorganica (DCSSI), UniVersità di Milano, Via G. Venezian 21,20133 Milano, Italy

ReceiVed June 21, 2007; ReVised Manuscript ReceiVed NoVember 8, 2007

ABSTRACT: Interpenetration in extended three-dimensional (3D) arrays has been investigated by a systematic analysis of thecrystallographic structural databases, using an ad hoc version of the program package TOPOS. In this paper we describe thecomprehensive results of our investigation of interpenetration in organic hydrogen-bonded 3D arrays from the Cambridge StructuralDatabase. The great interest in the self-assembly of organic molecules into hydrogen-bonded supramolecular arrays has promptedus to investigate these systems at a rather unusual level; that is, beyond the formation of synthons, we have examined the topologiesof the resulting networks and looked for their entanglements. Within 3D architectures we have extracted a complete list including122 different motifs showing the phenomenon of interpenetration (76 unseen by the original authors). These organic networksinclude species assembled by a single or by different building blocks; they are discussed and classified according to the previouslyintroduced classes of interpenetration and to other criteria peculiar of hydrogen-bonded organic species. Considerations of the possiblerelations of the building organic species and their network topology and on the factors determining interpenetration are here presented.The paper is also intended as a contribution to the study of the phenomena of polymorphism and supramolecular isomerism and ofthe crystal engineering of these complex architectures.

Introduction

Interpenetrating networks1 are nowadays common, and three-dimensional (3D) entangled arrays are often encountered in thefield of crystal engineering of metal-organic and inorganicnetworks, as well as in the design of supramolecular arrays ofweakly bonded organic molecules. To rationalize these complexsystems we need to investigate both the topology of theindividual networks and the “topology of interpenetration,”2 thatis, the way in which the individual nets are multiply (n-fold)entangled. This difficult and troublesome analysis can only becarried out by computer. We have previously reported ourstudies on interpenetrating metal-organic2d and inorganic2e

networks, using a tailored version of TOPOS (a package formultipurpose crystallochemical analysis). We describe now thecomprehensive results of our analysis of interpenetration inorganic hydrogen-bonded 3D arrays (strong hydrogen-bonds)from the Cambridge Structural Database (CSD, version 5.28of November 2006).

Organic structures were first chosen among other hydrogen-bonded compounds because the existence of well-definedmolecules connected by strong hydrogen bonds makes theconclusions about interpenetration phenomenon reliable andunambiguous. The other class of interpenetrating hydrogen-bonded nets that include metal-organic frameworks will beconsidered in a further publication.

The self-assembly of organic molecules into hydrogen-bondedsupramolecular arrays has been the subject of a number ofstudies concerning the synthetic approaches, the classificationand rationalization of the patterns, and the factors governing

the crystal engineering of these molecular materials. In principle,molecular building blocks (tectons) can be combined usingsuitable strategies to construct networks of desired topology.Unfortunately, while specific links between the building blocks(supramolecular synthons)3 can sometimes be controlled, theprocess leading from molecules to their periodic supramoleculararrays in crystals is still “a major challenge in the crystalengineering of molecular solids”.3a

In the attempt to get closer to this goal, as well as to possessa detailed knowledge of the synthons, more attention needs tobe devoted to the topology of the final architecture (targetnetwork) through the analysis of related structures reported inthe literature by searching for prototypical models that can fitthe specific problem. The large number of networks recentlyreported offers a rich variety of new structural types thatcontinuously increase our knowledge of these organic ormetal-organic extended systems. Indeed, the “network ap-proach” or topological approach to crystal chemistry4 is a usefultool for the analysis of network structures in that it simplifiescomplex species to schematized nets and allows easier com-parisons among packing trends that may help in the rationaldesign of such materials. However, many papers reportingcrystal structures of hydrogen-bonded organic species, especiallythe less recent ones, do not discuss the supramolecular nets(connectivity, dimensionality) and their topology (or sometimesassign incorrect ones) and generally overlook entanglement andinterpenetration phenomena (only a quarter of the structuresdescribed in this paper have been explicitly recognized asinterpenetrated).

The topological rationalization of hydrogen-bonded organicframes is more difficult than that of metal-organic frames(MOFs): in the latter case metallic nodes and organic spacersare usually well-recognizable entities, while in organic framesthe selection of the nodes is more ambiguous and the alternative

* To whom correspondence should be addressed. (D.M.P.) Phone: +39-0250314446. Fax: +39-0250314454. E-mail: [email protected].(V.A.B.) Phone: +7-8463345445. Fax: +7-8463345417. E-mail: [email protected].

† Samara State University.‡ Università di Milano.

CRYSTALGROWTH& DESIGN

2008VOL. 8, NO. 2

519–539

10.1021/cg0705660 CCC: $40.75 2008 American Chemical SocietyPublished on Web 01/23/2008

choice of the single tecton or of an oligomeric group as nodeleads to different, although interrelated, topological classifica-tions. The previously introduced classification of interpenetratednet arrays2d,e has also been applied here to hydrogen-bondedorganic frames, together with some specific parameters, and thepeculiar features of the interpenetration are discussed andcompared with those observed in other classes of materials. Notethat the world record of interpenetration (18-fold) has beenobserved in a hydrogen-bonded organic frame. Using the listof the resulting interpenetrated net arrays we have furthersearched the CSD, looking for other species with identical orvery similar composition, to possibly obtain new informationfor the study of polymorphism and in crystal design.

The TOPOS Approach. In this study we have consideredall organic (i.e., not containing metal atoms) compounds whosecrystal structures are completely determined (except, possibly,for all the positions of hydrogen atoms) and collected in theCambridge Structural Database (CSD, version 5.28 of November2006). To find the interpenetrating arrays in an automated modewe have used the program package TOPOS5 with somesubroutines especially designed to process hydrogen-bondedstructures. Only strong or moderately strong hydrogen bonds6

were considered.The following criteria were applied to recognize different

types of intermolecular A-H · · ·B hydrogen bonding (intramo-lecular hydrogen-bonds are irrelevant to our topological analy-sis):

(1) Only A, B ) N, O, F were considered, although nointerpenetrating arrays with F-H · · ·B or A-H · · ·F hydrogenbonds were found.

(2) The distance restriction R(A · · ·B) e 3.5 Å was used. Ifthe pertinent hydrogen atom positions were available, additionalrestrictions R(H · · ·B) e 2.5 Å and ∠ A-H · · ·B g 120° wereapplied.

(3) In addition, the geometrical criteria derived fromVoronoi-Dirichlet polyhedra (VDP) of A, B, and H atoms wereconsidered. A VDP is a convex polyhedron whose faces areperpendicular to segments connecting a central atom to other(surrounding) atoms, with each face bisecting the correspondingsegment. The atom size in the crystal structure can be evaluatedas the volume of its VDP or as Rsd, the radius of a sphere ofthe same volume as the VDP. Inasmuch as all surrounding atomsinfluence the VDP characteristics, VDP enables one to take intoaccount the whole environment of interacting atoms. In par-ticular, any pair of neighbor atoms has to be separated by acommon face for their VDPs, and the size of a face is largerfor stronger bonds. We have assessed this size as the solid angleof the face (Ω) expressed in percentage of the sum of solidangles for all faces (4π steradian, see also Figure 1). All contactsH · · ·B or A · · ·B with Ω < 10% were discarded as weakhydrogen bonds.

(4) As in previous papers,2d,e to find valence bonds weconsider two spheres around each atom: an internal sphere ofSlater’s radius and an external sphere with the radius equal toRsd. A valence bonding is assumed to exist if there are at leasttwo intersections between the spheres of interacting atoms.5 Inaddition, this criterion enabled us to automatically recognizesymmetrical A-H-B and resonance A-H T H-B hydrogenbonds, by finding two valence contacts with participation ofhydrogen atoms.

The validity of these criteria was checked by comparison with60 899 compounds where hydrogen bonds (A, B ) N, O) existaccording to CSD information7 and with all hydrogen-bondedinterpenetrating arrays listed by Batten (http://www.chem.mo-

nash.edu.au/staff/sbatten/interpen/examples.html), and no dis-crepancies were found.

We have used the TOPOS algorithm as recently applied tostudy valence bonded metal-organic and inorganic 3D frame-works, including inorganic compounds with hydrogen-bonds.2d,e

We consider here crystal structures that contain organicmolecules only (except for few species containing also someinorganic counteranions) and, since often the location of watermolecules is poorly determined, we discarded cases where watermolecules take part in the hydrogen-bond network.

122 interpenetrating arrays were revealed (Table 1) consistingof isolated organic molecules linked into 3D frameworks byhydrogen bonds (no valence bonded polymeric substructureswere found). The nodes of the networks are therefore singlemolecules (tectons), a choice that naturally comes out from theautomatic search routine (we call this the “standard topology”).Alternative more complex nodes could also be envisaged byselecting groups of linked molecules (ring synthons, vide infra),thus producing different topologies. We use a number ofpreviously proposed descriptors to classify the interpenetrationpatterns.2d,e

Seventy-six interpenetrated net arrays formed by hydrogenbonds between the ligands of metal complexes have been alsofound, but they will be discussed in a separate publication.

Let us emphasize that both search and classification of theinterpenetrating hydrogen-bonded arrays are performed here forthe first time using strict computer algorithms. Such approachallows one to find out all the cases irrespective of the crystalstructure complexity and to avoid faults and misses of humanhandmade analysis. In particular, 71% of the structures listedin Table 1 were not recognized as interpenetrated by the authorsof original works and were not presented in the most compre-hensive Batten’s collection. Furthermore, in 25% of thestructures the 3D nature of the hydrogen-bond interactions wasnot recognized.

Analysis of the Results. The results of the present analysisare listed in Table 1, which includes 122 different interpenetrat-

Figure 1. Voronoi-Dirichlet polyhedron of a hydrogen atom in thecrystal structure of -quinol (HYQUIN05). Hydrogen bonds are shownby dash-and-dot lines. The solid angle of the pyramid at the oxygenatom, Ω(H · · ·O) ) 20.1%, is equal to the solid angle of thecorresponding VDP face.

520 Crystal Growth & Design, Vol. 8, No. 2, 2008 Baburin et al.

Tab

le1.

Inte

rpen

etra

ting

Hyd

roge

n-B

onde

dN

etw

orks

a

RE

FCO

DE

nam

ety

pe(n

ode)

net

Zcl

ass

sym

met

ryH

BR

Ino

te

3-co

nnec

ted

nets

IBU

XIN

3,5-

dini

trob

enza

mid

ehy

drat

eA

Adi

a-f

6Ia

[0,0

,1]

(6.0

0)1.

33I,

lvt,

a,b,

cA

HE

GO

J2-

amin

o-4-

(4-c

hlor

ophe

nylth

io)-

6-m

orph

olin

opyr

imid

ine

AA

dia-

f2

Ia[0

,0,1

](7

.01)

1.33

I,lv

t,a,

bIQ

AFE

L2-

brom

o-6-

etho

xy-7

-hyd

roxy

-6,7

-dih

ydro

-5H

-im

idaz

o[1,

2-b]

[1,2

,4]

tria

zin-

3-on

eA

Adi

a-f

2Ia

[0,0

,1]

(4.2

2)1.

33I,

lvt,

a,b

QE

CN

AN

1-hy

drox

y-2-

phen

yl-1

H-2

,4,1

-ben

zodi

azab

orin

-3-o

neA

Adi

a-f

2Ia

[0,0

,1]

(7.7

4)1.

33I,

lvt,

a,b

KU

STO

H(2

R,9

S,12

S,13

R)-

12-(

cycl

ohex

ylm

ethy

l)-9

-[[(

1,1-

dim

ethy

leth

oxy)

carb

onyl

]am

ino]

-13-

hydr

oxy-

2-(m

orph

olin

omet

hyl)

-6,1

0,14

-tri

oxo-

1,7-

diox

a-11

-aza

cycl

otet

rade

cane

AA

eta

2Ia

[0,0

,1]

(18.

93)

2.00

a,b

UG

UM

UE

5-(t

riflu

orom

ethy

l)ur

acil

AA

etb

2Ia

[0,0

,1]

(5.1

9)1.

33I,

nbo,

a,b

SAY

NA

I01

3-(c

hlor

oace

tam

ido)

pyra

zole

AA

lig3

Ia[0

,0,1

](5

.20)

1.33

I,lv

t,a

QA

CPE

P2-

amin

o-5-

n-bu

tyl-

3-et

hyl-

6-m

ethy

l-4(

3H)p

yrim

idin

one

AA

lig2

Ia[0

,0,1

](8

.81)

1.33

I,lv

t,a,

bK

APF

IR2,

6-di

amin

opyr

idin

ium

4-ni

trop

heno

late

4-ni

trop

heno

lA

BC

(AB

)cd

s-3-

Pnn

a3

Ia[1

,0,0

](1

3.61

)1.

25a

KA

NV

UR

4-he

xyl-

6-am

ino-

3-ph

enyl

-5-c

yano

-2H

,4H

-pyr

ano(

2,3-

c)py

razo

leA

Apc

u-h

2Ia

[1,1

,1]

(8.4

8)1.

33V

III,

nbo,

aSA

YM

UB

01bi

s(be

nzen

e-1,

3,5-

tric

arbo

xylic

acid

)tr

is(1

,2-b

is(4

-pyr

idyl

)eth

ane)

AB

(A)

srs

18II

Ib4

PIV

s/i

1.00

AD

EN

SLad

enin

ium

sulf

ate

AB

(AB

)sr

s2

IIa

i1.

67a

NU

ZK

AU

met

hyla

mm

oniu

m4-

nitr

ophe

nola

teA

B(A

B)

srs

2II

ai

1.00

aT

IPK

IMN

′-((S

)-N

′-ben

zoyl

-met

hyl-

2-ph

enyl

tyro

syl)

-(S)

-phe

nyla

lani

necy

cloh

exyl

amid

eA

Asr

s2

Ia[0

,0,1

](1

0.68

)1.

33IX

,di

a,a,

b

HN

AFP

Y10

1-(4

-ace

tyl-

5-m

ethy

l-2-

fury

l)-1

,3-d

ideo

xy-3

-nitr

o--

D-x

ylop

yran

ose

AA

ths

3Ia

[0,0

,1]

(17.

98)

1.33

aPA

ZH

OO

3-ca

rbox

ypyr

idin

ium

hydr

ogen

chlo

rani

late

AB

(AB

)th

s2

Ia[0

,1,0

](5

.43)

1.00

a4-

conn

ecte

dne

tsX

EB

TIH

tetr

akis

(4-(

3-hy

drox

yphe

nyl)

phen

yl)m

etha

nebi

s(be

nzoq

uino

ne)

AB

(A)

dia

11Ia

[0,0

,1]

(6.9

1)1.

00Si

(VO

JFA

B)

(4-(

(6-o

xopy

rid-

2-yl

)eth

ynyl

)phe

nyl)

sila

necl

athr

ate

AA

dia

8Ia

[1/2

,1/2

,1/2

](1

9.9)

2.00

IV

OJF

AB

(4-(

(6-o

xopy

rid-

2-yl

)eth

ynyl

)phe

nyl)

met

hane

clat

hrat

eA

Adi

a7

Ia[0

,1,0

](7

.35)

2.00

IG

EJV

EW

adam

anta

ne-1

,3,5

,7-t

etra

carb

oxyl

icac

idA

Adi

a5

Ia[1

,0,0

](7

.51)

2.00

IJA

DM

AD

met

hane

tetr

apro

pion

icac

idA

Adi

a5

Ia[1

,0,0

](9

.46)

2.00

IX

UV

BA

R(m

etha

nete

tray

ltetr

a-4,

1-ph

enyl

ene)

tetr

akis

(bor

onic

acid

)-

two

diff

eren

tcl

athr

ates

:X

UV

BIZ

AA

dia

5Ia

[1,0

,0]

(10.

6–10

.8)

2.00

I

XU

VB

EV

(sila

nete

tray

ltetr

a-4,

1-ph

enyl

ene)

tetr

akis

(bor

onic

acid

)pe

ntak

is(e

thyl

acet

ate)

hydr

ate

clat

hrat

eA

Adi

a5

Ia[1

,0,0

](1

0.84

)2.

00I

JUT

GO

U4-

amin

ophe

nyl(

4′-c

yano

phen

yl)s

ulfo

neA

Adi

a4

IIIa

[0,1

,0]

(8.1

2)/i

1.00

aO

HU

JOQ

16,2

0-di

nitr

o-(3

,4,8

,9)-

dibe

nzo-

2,7-

diox

a-5,

10-d

iaza

[4.4

.4]p

rope

llane

AA

dia

4Ia

[1,0

,0]

(6.8

5)1.

00a

QU

SME

W2,

6-di

met

hyl-

1,3,

5,7-

cycl

ooct

atet

raen

e-1,

3,5,

7-te

trac

arbo

xylic

acid

AA

dia

4II

Ia[1

,0,0

](1

1.09

)/2-

axis

1.00

aC

INM

ER

pyri

dine

3,4-

dica

rbox

ylic

acid

AA

dia

3Ia

[0,0

,1]

(5.2

8)1.

00a

EJU

ZO

Yci

s,ci

s-1,

3,5-

cycl

ohex

anet

rica

rbox

ylat

ehe

mik

is(1

,4-b

is(2

-(4-

pyri

dini

o)et

heny

l)be

nzen

e)A

B(A

)di

a3

Ia[1

,0,0

](4

.79)

1.00

a

FAFX

UF

(+)-

pino

resi

nol

AA

dia

3Ia

[1,0

,0]

(8.2

5)1.

00a,

bG

EST

AZ

met

hane

tetr

acet

icac

idA

Adi

a3

Ia[0

,0,1

](8

.96)

2.00

IG

IMSI

E2-

oxo-

6,6-

dihy

drox

y-ad

aman

tane

-1,3

,5,7

-tet

raca

rbox

ylic

acid

AA

dia

3Ia

[1,0

,0]

(7.3

3)2.

00I

NT

RT

AC

/01

nitr

ilotr

iace

ticac

idA

Adi

a3

Ia[0

,0,1

](6

.49)

1.00

cT

ER

RU

DN

-ace

tyl-

L-g

luta

mic

acid

AA

dia

3Ia

[1,0

,0]

(4.9

0)1.

50V

II,

aB

AX

KIV

amm

oniu

mbi

s(tr

ans-

1,2-

bis(

pyri

d-4-

yl)e

then

eN

,N′-d

ioxi

de)

AB

(A)

dia

2II

a2-

axis

1.00

BE

RC

UW

junc

eine

AA

dia

2Ia

[1/2

,1/2

,0]

(10.

43)

1.00

a,b

BO

LZ

IL2-

hydr

oxy-

N-m

ethy

lcya

noac

etam

ide

AA

dia

2Ia

[0,1

,0]

(3.9

5)1.

00a

CY

AN

AM

01cy

anam

ide

AA

dia

2II

ai

1.00

aFE

WSA

Cci

s-an

ti-4

a,8a

-dim

ethy

l-4b

,5,8

a,8b

-tet

rahy

drop

yrid

o(2

′,3′:3

,4)c

yclo

buta

(1,2

-b)p

yrid

ine-

2,6(

1H,4

aH)-

dion

eA

Adi

a2

IIa

i1.

00a,

b

HIV

BE

Tge

nist

ein

mor

phol

ine

AB

(A)

dia

2II

ai

1.00

aIN

UJU

Wte

trak

is(1

,2-d

ihyd

ro-2

-oxo

-5-p

yrid

yl)s

ilane

-si

xdi

ffer

ent

clat

hrat

esIN

UK

AD

,YIN

JOU

/01,

YIN

KA

H,Y

INK

EL

,YIN

KIP

AA

dia

2Ia

[0,0

,1]

(7.6

6–9.

58)

2.00

JAR

BO

U2,

5-bi

s(4-

amin

ophe

nyl)

-1,3

,4-o

xadi

azol

eA

Adi

a2

IIa

i1.

00a

Interpenetrated 3D Networks of H-Bonded Organic Species Crystal Growth & Design, Vol. 8, No. 2, 2008 521

Tab

le1.

Con

tinu

ed

RE

FCO

DE

nam

ety

pe(n

ode)

net

Zcl

ass

sym

met

ryH

BR

Ino

te

KE

RB

AK

bis(

1,3-

dim

ethy

lure

ido)

met

hane

AA

dia

2II

ai

1.00

a,b

LA

YFU

Ndi

(2-(

2-hy

drox

yeth

oxy)

phen

yl)

dite

lluri

deA

Adi

a2

IIa

i1.

00a

LU

YG

AN

bis(

C-m

ethy

lcal

ix[4

]res

orci

nare

ne)

tris

(4,4

′-bip

yrid

yl)

AB

(A)

dia

2Ia

[1/2

,1/2

,0]

(15.

28)

2.00

PAN

GO

B4-

amin

o-3-

(1,2

,4-t

riaz

ol-1

-ylm

ethy

l)-1

H-1

,2,4

-tri

azol

e-5(

4H)-

thio

neA

Adi

a2

IIa

i1.

00a

SEJS

IJ1,

1′-(

1,2-

etha

nedi

yl)-

bis(

l-py

rogl

utam

icac

id)

AA

dia

2Ia

[1,0

,0]

(7.5

1)1.

00a

SIV

TU

M(E

,E)-

4-am

ino-

3-cy

ano-

4-m

etho

xy-1

-(4-

met

hoxy

phen

yl)-

2-az

a-1,

3-bu

tadi

ene

AA

dia

2II

ai

1.00

a

TA

QX

AL

1-(c

arbo

xym

ethy

l)ur

acil

AA

dia

2Ia

[0,1

,0]

(4.6

3)2.

00a

VO

BFA

T2,

6-di

met

hylid

enea

dam

anta

ne-1

,3,5

,7-t

etra

carb

oxyl

icac

id-

thre

edi

ffer

ent

clat

hrat

esV

OB

FEX

,V

OB

FIB

AA

dia

2II

ai

2.00

I

VO

BFO

H2,

6-di

met

hylid

enea

dam

anta

ne-1

,3,5

,7-t

etra

carb

oxyl

icac

id-

two

diff

eren

tcl

athr

ates

VO

BFU

NA

Adi

a2

IIa

2-ax

is2.

00I

VO

BG

AU

2,6-

dim

ethy

liden

eada

man

tane

-1,3

,5,7

-tet

raca

rbox

ylic

acid

clat

hrat

eA

Adi

a2

Ia[0

,0,1

](1

0.93

)2.

00I

WE

ZPE

W3-

hydr

oxy-

1-m

ethy

l-4-

oxop

yrid

ine-

6-ca

rbox

ylic

acid

AA

dia

2Ia

[0,1

,0]

(4.5

1)1.

00a,

bZ

ER

MU

E6-

met

hylis

ocyt

osin

e-5-

acet

icac

idA

Adi

a2

Ia[1

,0,0

](4

.90)

1.50

IX,p

cu,a

,bZ

ER

NE

P6-

met

hylis

ocyt

osin

e-5-

prop

ioni

cac

idA

Adi

a2

Ia[1

,0,0

](5

.71)

2.50

IX,

pcu,

a,b

BE

QV

UO

5-hy

drox

yiso

phth

alic

acid

-4,

4′-t

rim

ethy

lene

dipy

ridi

neA

B(A

)cd

s4

IIIa

[0,1

,0]

(7.3

9)/i

1.00

SID

VO

Q3,

4-di

hydr

oxyb

enza

ldeh

yde-

4-ni

trop

heny

l-hy

draz

one

AA

cds

3Ia

[1/2

,1/2

,0]

(7.1

8)1.

00a

ZU

HH

ITp-

acet

amid

oper

benz

oic

acid

AA

cds

3Ia

[1,0

,0]

(5.0

5)1.

00a

ZU

HH

OZ

p-pr

opan

amid

oper

benz

oic

acid

AA

cds

3Ia

[1,0

,0]

(4.8

9)1.

00a

DA

TN

BZ

1,3-

diam

ino-

2,4,

6-tr

initr

oben

zene

AA

cds

2Ia

[0,1

,0]

(5.2

0)1.

00a

BE

WY

OR

5-flu

oro-

1,3-

diam

ino-

2,4,

6-tr

initr

oben

zene

AA

cds

2Ia

[0,1

,0]

(5.1

2)1.

00a

EN

AN

IQ4-

((2-

(4-a

min

ophe

nyl)

ethy

l)su

lfan

yl)p

heno

lA

Acd

s2

Ia[0

,1,0

](5

.86)

1.00

aH

OT

SOY

4,5-

dihy

dro-

7-am

ino-

5-ox

o-[1

,2,4

]-tr

iazo

lo[1

,5-a

]py

rim

idin

eA

Acd

s2

Ia[1

,0,0

](5

.08)

1.50

I,ne

w6-

c,a

JIG

CIL

4-am

inoi

soth

iazo

lo(4

,3-d

)iso

xazo

leA

Acd

s2

Ia[0

,1,0

](6

.37)

1.00

a,b

JUN

QIS

4-ca

rbox

amid

o-1-

cuba

neca

rbox

ylic

acid

AA

cds

2Ia

[0,1

,0]

(7.1

3)1.

50c

TA

DR

UM

2,2′

-dia

min

o-4,

4′-b

i-1,

3-th

iazo

lium

fum

arat

eA

B(A

B)

cds

2Ia

[1,0

,0]

(5.2

8)1.

50a

TA

PZO

A2-

amin

oeth

ene-

1,1,

2-tr

icar

boni

trile

AA

cds

2Ia

[0,1

,0]

(5.7

5)1.

00c

WA

KFO

Ete

reph

thal

ate

bis

dim

ethy

lam

mon

ium

AB

(A)

cds

2Ia

[1,0

,0]

(9.6

4)1.

00W

OV

VU

Yp-

form

amid

oben

zoic

acid

AA

cds

2Ia

[0,1

,0]

(3.8

6)1.

00a

BU

XR

IV2,

7-di

met

hyltr

icyc

lo[4

.3.1

.13,8

]und

ecan

e-sy

n-2,

syn-

7-di

ol-

eigh

tdi

ffer

ent

clat

hrat

es:

BU

XR

IV10

,L

OR

QO

Y,

LO

RQ

UE

,PO

LFI

F,Q

UL

KO

X,

QU

LL

AK

,V

USY

EN

AA

gis

2II

ai

1.00

III,

lvt

WO

YL

EB

2,7-

dim

ethy

l-9-

thia

tric

yclo

[4.3

.1.1

3,8

]und

ecan

e-an

ti-2

,ant

i-7-

diol

AA

gis

2II

ai

1.00

III,

lvt

NU

GN

IMan

ti-2

,2′-b

i(tr

icyc

lo[3

.3.0

.03,7

]oct

ylid

ene)

-4,4

′-dio

lA

Agi

s2

Ia[0

,0,1

](6

.13)

1.00

III,

lvt,

a,b

CA

LV

AM

acet

amid

ine

AA

gis

2Ia

[0,0

,1]

(5.7

0)1.

00II

I,lv

t,a

UD

AY

UT

023,

3′,5

,5′-t

etra

met

hyl-

4,4′

-bip

yraz

olyl

AA

lcv

6II

Ia[0

,0,1

](8

.60)

/c-g

lide

1.33

II,

srs

HU

XM

IW3,

3′,5

,5′-t

etra

met

hyl-

4,4′

-bip

yraz

olyl

tris

chlo

rofo

rmA

Alc

v2+

2II

a+II

ai

1.00

II,

srs

HU

XM

UI

3,3′

,5,5

′-tet

ram

ethy

l-4,

4′-b

ipyr

azol

ylm

etha

nol

(3:1

)A

B(A

)lc

v6

IIIa

[0,1

,0]

(9.6

4)/i

1.00

II,

srs

LU

VPU

N1,

6-di

hydr

oxyd

odec

amet

hylh

exas

ilane

AA

lvt

3Ia

[0,0

,1]

(29.

54)

1.00

III,

dia,

aB

OL

NO

F3,

3′-(

ethy

lene

di-i

min

o)-b

is(3

-met

hyl-

2-bu

tano

neox

ime)

AA

lvt

2Ia

[0,0

,1]

(6.2

7)1.

00a

CE

YSO

O3,

3′-(

trim

ethy

lene

di-i

min

o)-b

is(3

-met

hyl-

2-bu

tano

neox

ime)

AA

lvt

2II

ac-

glid

e1.

00a,

bFA

XH

OB

012,

3-bu

tane

dion

edi

hydr

azon

eA

Alv

t2

Ia[0

,0,1

](4

.11)

1.00

a,b

HE

KW

UP

6-am

ino-

1,3-

dim

ethy

l-5-

hydr

oxyi

min

omet

hyl-

2,4(

1H,3

H)-

pyri

mid

ined

ione

AA

lvt

2II

ai

1.00

a,b

ICE

RA

K11

,23-

di-t

-but

yl-3

,7,1

5,19

-tet

ra-a

zatr

icyc

lo(1

9.3.

1.19

,13)

hexa

cosa

-1(2

5),9

(26)

,10,

12,2

1,23

-hex

aene

-2,8

,14,

20-t

etra

one

AA

lvt

2Ia

[0,0

,1]

(13.

68)

1.00

a,b

MIZ

RIW

5,11

,17,

23-t

etra

-t-b

utyl

-25,

27-d

ihyd

roxy

-26,

28-b

is(3

-hy

drox

yben

zoyl

oxy)

calix

[4]a

rene

AA

lvt

2II

ai

1.00

a

TA

KFE

Rtr

ans-

2,8-

dihy

drox

y-2,

4,4,

6,6,

8,10

,10,

12,1

2-de

cam

ethy

l-5,

11-

dica

rbac

yclo

hexa

silo

xane

(-C

H2-

)A

Alv

t2

Ia[0

,0,1

](9

.85)

1.00

III,

dia,

a

TA

KFU

Htr

ans-

2,8-

dihy

drox

y-2,

4,4,

6,6,

8,10

,10,

12,1

2-de

cam

ethy

l-5-

carb

acyc

lohe

xasi

loxa

ne(-

O-)

AA

lvt

2Ia

[0,0

,1]

(11.

36)

1.00

III,

dia,

a


Tab

le1.

Con

tinu

ed

RE

FCO

DE

nam

ety

pe(n

ode)

net

Zcl

ass

sym

met

ryH

BR

Ino

te

VA

TPA

Iac

etyl

acet

one

diox

ime

AA

lvt

2Ia

[0,0

,1]

(5.9

8)1.

00IV

,dia

,a,b

WE

QSU

G(-

)-ph

enyl

ahis

tinA

Alv

t2

Ia[0

,0,1

](8

.31)

1.00

a,b

KA

PVIH

2,2′

′,6,6

′′-te

tram

ethy

l-4,

4′′-t

erph

enyl

diol

AA

nbo

4Ia

[0,0

,1]

(10.

01)

1.00

V,

pcu

BA

SVU

M01

diet

hyl

2,5-

diam

inot

erep

htha

late

AA

nbo

2Ia

[0,0

,1]

(6.9

4)1.

00a

HIK

NO

E1,

4-bi

s(hy

drox

ymet

hyl)

cuba

neA

Anb

o2

Ia[0

,0,1

](5

.73)

1.00

V,

pcu,

a,b

HY

QU

IN05

-hy

droq

uino

ne-

eigh

tdi

ffer

ent

clat

hrat

esB

ICZ

IX,

BU

SPA

G,

HQ

UA

CN

/01,

HY

QH

CL

/01,

JAM

KE

N,

QU

OL

SO/0

1,Z

ZZ

VL

G01

,Z

ZZ

VL

I01

AA

nbo

2Ia

[0,0

,1]

(5.4

7)1.

00V

,pc

u

LE

BK

UZ

2,2′

-dim

ethy

l-4,

4′-b

iimid

azol

eA

Anb

o2

Ia[0

,0,1

](5

.00)

1.00

VI,

pcu,

aR

ASB

OD

[2-h

ydro

xyph

enyl

)-(3

,5-d

ihyd

roxy

phen

yl)m

etha

ne]

bis(

4,4′

-bip

yrid

ine)

AB

(A)

neb

8II

Ia[0

,0,1

](1

5.76

)/i

1.00

cJU

KV

OA

benf

otia

min

eA

Ane

b2

Ia[0

,0,1

](1

4.43

)1.

50I,

lig,

aM

IGR

ID1,

3,5-

tris

(4-h

ydro

xyph

enyl

)ben

zene

AA

neb

2II

ai

1.25

aH

AG

PUA

1,2-

bis(

3,4-

dim

etho

xyph

enyl

)-1,

2-et

hane

diol

AA

qtz

2Ia

[0,0

,1]

(9.6

6)1.

00a,

bIT

UX

IE4-

hydr

oxyb

enza

ldeh

yde

(4-n

itrop

heny

l)hy

draz

one

AA

sqc1

872

IIa

i1.

50a

TA

GU

DN

/01

1,2,

3-tr

iam

ino-

guan

idin

ium

nitr

ate

AB

(AB

)sr

a2

Ia[1

,0,0

](8

.39)

1.00

aD

ASD

IL1,

10-d

ihyd

roxy

bicy

clo(

8.8.

8)he

xaco

sane

.A

Auo

c1+

1he

tero

inte

rpen

etra

tion

1.00

III,

dia,

a,b

CA

XR

OI

17R

-phe

nyl-

andr

ost-

5-en

e-3

,17

-dio

lA

Auo

c3

Ia[0

,0,1

](1

2.49

)1.

00II

I,di

a,a,

b5-

conn

ecte

dne

tsD

OV

SUC

prot

osap

pani

nA

AA

bnn

2II

a2-

scre

w1.

20a

DA

CY

EL

3,5-

diam

ino-

2,4,

6-tr

initr

oben

zoic

acid

AA

nov

2Ia

[1,0

,0]

(7.2

5)1.

20I,

bcu,

aM

UR

QO

FC

-met

hylc

alix

[4]r

esor

cina

rene

bis(

4-py

ridy

lmet

hylid

yne)

hydr

azin

e1:

2A

B(A

)sq

p3

Ia[1

,0,0

](1

3.81

)1.

786-

conn

ecte

dne

tsM

EQ

QU

U2,

4-di

hydr

ogen

cis,

tran

s,ci

s,tr

ans-

1,2,

3,4-

cycl

obut

anet

etra

carb

oxyl

ate

bis(

imid

azol

ium

)A

B(A

)pc

u2

IIa

2-sc

rew

1.20

I,a,

b

PIC

TIE

3′-d

eoxy

sang

ivam

ycin

AA

pcu

2Ia

[0,0

,1]

(5.0

8)1.

00a,

bQ

IFQ

IFN

-(ca

rbam

oylm

ethy

l)im

inod

iace

ticac

idA

Apc

u2

IIa

i1.

00a

UJO

FEE

tetr

akis

(4-h

ydro

xyph

enyl

)met

hane

AA

pcu

2II

ai

1.00

UJO

FII

tetr

akis

(4-h

ydro

xyph

enyl

)sila

neA

Apc

u2

IIa

i1.

00c

WU

QY

OW

3,3,

9,9-

tetr

akis

(4-(

2,6-

diam

inot

riaz

en-4

-yl)

benz

yl)-

2,4,

8,10

-tet

raox

ospi

ro[5

.5]u

ndec

ane,

two

diff

eren

tcl

athr

ates

WU

CY

UC

AA

bp1

2II

ai

2.67

I,c

8-co

nnec

ted

nets

BA

WJU

F5,

10,1

5,20

-tet

raki

s(4-

((N

-n-b

utyl

carb

amoy

l)m

etho

xy)p

heny

l)po

rphy

rin

AA

bcu

2II

ai

1.00

a,b

mix

edco

nnec

tivi

tyne

tsU

LA

WE

Jm

alon

icac

idbi

s(is

onic

otin

amid

e)A

B(A

B)

dmd

3Ia

[0,0

,1]

(15.

68)

1.20

I,pt

s,a

APY

RD

N4-

amin

opyr

idin

hem

iper

chlo

rate

AB

C(A

BC

)bp

52

Ia[1

,0,0

](1

1.22

)1.

10N

-H-N

,sr

a,a

APY

RD

N01

4-am

inop

yrid

inhe

mip

erch

lora

teA

BC

(AB

C)

bp4

2II

ai

1.00

N-H

-N,

lon,

aV

AK

VIN

hydr

oqui

none

bis(

ison

icot

inam

ide)

AB

(AB

)bp

23

Ia[0

,1,0

](5

.41)

1.20

I,cd

s,a

TIP

WIY

/01

urea

E-b

uten

edio

icac

id(2

:1)

AB

(AB

)bp

22

Ia[1

,0,0

](5

.54

Å)

1.60

I,a

VE

JXA

J/01

urea

buta

nedi

oic

acid

(2:1

)A

B(A

B)

bp2

2Ia

[1,0

,0]

(5.6

4Å

)1.

60I,

aX

OM

POE

guan

idin

ium

hydr

ogen

mon

ofluo

roph

osph

ate

AB

(AB

)dm

c2

Ia[1

,0,0

](6

.78)

1.43

I,rt

f,a

JOZ

ZE

Dad

enin

ehy

drog

enpe

roxi

de(1

:1)

AB

(AB

)bp

33

Ia[1

/2,1

/2,0

](6

.97

Å)

1.43

I,ne

w(3

,6)-

c,a

CU

TY

EV

4,4′

-bip

heno

lbi

s(4,

4′-b

iphe

nola

te)

mes

o-5,

5,7,

12,1

2,14

-hex

amet

hyl-

1,4,

8,11

-tet

ra-a

zacy

clot

etra

deca

neA

BC

(AB

)tf

c3

Ia[1

,0,0

](9

.96)

1.00

HIB

DE

D/0

1gu

anid

iniu

m4-

carb

oxyb

enze

nesu

lfon

ate

AB

(AB

)gr

a2

IIa

i1.

50I,

aE

TIG

AP

guan

idin

ium

4-hy

drox

y-3-

carb

oxyb

enze

nesu

lfon

ate

AB

(AB

)hm

s2

IIa

1.50

I,a

TA

PIPZ

N,N

,N′,N

′-tet

ra-a

min

o-pi

pera

zind

iium

bis

azid

eA

B(A

B)

rtl

2Ia

[1,0

,0]

(6.4

1)1.

00a

TIJ

KO

M(4

,4′-b

ipyr

idin

e)3(

2,3,

5,6-

tetr

ahyd

roxy

-1,4

-ben

zoqu

inon

e)2

AB

(AB

)fs

c3

Ia[1

,0,0

](8

.89)

1.00

aFo

rth

eco

lum

n“n

ote”

see

text

.T

here

fere

nces

for

the

RE

FCO

DE

are

liste

din

alph

abet

ical

orde

rfr

omnu

mbe

r25

for

AG

LU

AM

10to

num

ber

181

for

ZZ

ZV

LI0

1.


ing 3D arrays. These species are reported in CSD with a greaternumber of entries since different Refcodes are attributed in CSDto multiple crystal structure determinations (e.g., NTRTAC,NTRTAC01) or to compounds that contain different guestsolvents but give the same supramolecular architecture, that is,the same topology (e.g., XUVBAR, XUVBIZ).

The columns of Table 1, besides the Refcode and the chemicalformula, report the following information:

(a) TYPE (NODE): AA (homomolecular), AB, or ABC areused for one, two, or three different building units that contributeto the networks (solvent molecules are not included); note,however, that these symbols do not give the actual ratio of thecomponents. Homomolecular species with crystallographicallydifferent molecules are classified AA. The networks nodes, whennecessary, are also specified; that is, for TYPE AB we can haveas nodes only molecules A or both A and B: in the formersituation the TYPE (NODE) indication is AB(A), while in thelater one we give AB(AB). Moreover, note that a molecule, inprinciple, can work both as a node and as a spacer (2 connectingnode) depending on the number and directionality of thehydrogen bonds.

(b) TOPOLOGY: we give the three-letter symbol of the netproposed by O’Keeffe8 as can be retrieved from RCSR database(Reticular Chemistry Structure Resource, http://rcsr.anu.edu.au/).Seven nets found here are not listed in RCSR, but one (sqc187)was found in EPINET database (Euclidean Patterns in Non-Euclidean Tilings, http://epinet.anu.edu.au/, names starting withsqc)9 and another (cds-3-Pnna) in the recent list produced byBlatov.10 Five nets are new, and we propose as names bp1,bp2, bp3, bp4, bp5. For the nomenclature and recognition ofnew nets we follow the lines in refs 1e and 5. The correspondingSchläfli Symbol before the three-letter symbol11 is also reportedthroughout the text and in the schemes showing the molecularbuilding blocks (see later). In some cases for more detaileddescription of the net topology we use other topological indicessuch as Coordination Sequences and Vertex Symbols.1e,5

(c) Z/CLASS/SYMMETRY: the degree of interpenetrationZ and the interpenetration Class2d,e are reported. The columnSYMMETRY gives the interpenetration vectors (Å) and/or thesymmetry operations that relate equivalent interpenetrating nets.

(d) HBRI (H-Bond Ratio Index): this parameter gives theratio (no. of total effective hydrogen bonds per asymmetric unit/no. of theoretical single bonds required by connectivities of thenodes). The following equation can be used:

HBRI ) [2(Ntot/Z') - HBS]/(Σ Con Nodes)

with Ntot ) total number of intermolecular hydrogen bonds inthe crystallographic unit cell; Z′ (corrected Z) ) number ofeffective repeated units (whole molecules) in the cell takinginto account the possible special positions; HBS ) number ofhydrogen bonds connecting the independent spacers (if any) tothe nodes; Σ Con Nodes ) sum of the connectivities of all theindependent nodes. A more direct evaluation can be performedby simple inspection of the molecular drawings reported in theschemes (see below). HBRI depends on the choice of the nodesand could be considered as an indication of the stability of theframework; that is, values >1 reveal the presence of multiplehydrogen-bond bridges joining the building blocks. Simpleconsiderations for type AA nets, first introduced many yearsago,12 based on the balance of the number of hydrogen-bonddonor and acceptor groups in the building block show that onlywith even net connectivities we can have an exact match andHBRI ) 1, while with odd connectivities the value of HBRImust be >1. This seems also to indicate that in type AA nets

the odd connectivities, due to the possibility of facing the above-mentioned mismatch in the balance, are less likely to occur (seebelow) because the molecular structure is not always such toform stable cyclic synthons or multiple hydrogen-bond bridges.

(e) The NOTE column gives some extra information. Thepresence of a certain supramolecular “ring synthons” is reportedgiving the numbers from Scheme 1 (I–IX) and Figure 6 (X).When a certain “ring synthon” gives rise to a “ring synthonnet” the different topology is also indicated. With “ring synthonnet” we mean that the nodes of the alternative net are locatedat the center of the group of molecules (tectons) linked in thesupramolecular synthon and the edges of the alternative netcorrespond to tectons (see below Figures 6 and 7). Thisdemonstrates the unavoidable arbitrariness that, considering alsothe subjective choice of the Ω lower limit, is involved in thetopology assignment of hydrogen-bonded organic nets. Note,however, that the topologies of the “standard” net and thecorresponding “ring synthon net” are rigorously interrelated(vide infra).13a Further information is labeled as follows: (a) ifthe interpenetration was not recognized in the original paper(87 cases), (b) if 3D hydrogen-bonded nets were not detected(30 cases), (c) if connectivity and/or topology of the net werewrongly assigned, and/or some hydrogen-bonds were missed(seven cases).

The topology distribution and the most frequently observednets are shown in Figures 2 and 3. An evident difference fromvalence-bonded interpenetrating MOFs and from interpenetratinginorganic networks is that the main part of topologies are relatedto 4-c nets (ca. 68%), while 3-c (ca. 13%) and 6-c (5%) onesare rather rare. The rarity of 3-c nets can be considered inrelation to the point quoted above (discussion on HBRI and onodd and even connectivities).12 The analysis of more than 20003D hydrogen-bonded homomolecular single nets in CSD13a,b

is in very good agreement with the expected trend; that is, theeven connectivities are largely dominant over the odd ones. Atthe same time, in the single nets high even connectivities (6-cor 8-c nets) are very frequent, a fact that can be related to thetendency to form a molecular close packing (see Figure 2 bottomand Figure 4 top). The different distribution of the topologiesreported in Figure 2 with respect to other interpenetrating 3Dsystems is confirmed by the fact that diamondoid nets, the mostnumerous nets, are only 31.1% (vs. 42–44% in interpenetratedMOFs and inorganic networks).14

It may be surprising to some readers that the total number ofinterpenetrated nets is so small. Preliminary results reported inFigure 4 (bottom) show that the interpenetrated 3D nets are onlya small fraction of all 3D nets; further, the incidence ofinterpenetration in hydrogen-bonded nets is 10 times smallerthan that for valence bonded ones (MOFs). This striking resultis in contrast to the fact that infinite hydrogen-bonded nets are

Scheme 1


three times more frequent than MOFs: hydrogen-bond interac-tions more often form infinite motifs. It follows that it is easierto observe subnets that are cross-linked (hence destroyinginterpenetration) by such interactions giving a unique 3D netwith high connectivity (>6, see Figure 4 top).

Observing the other parameters we note that for the largemajority of the nets the value of the degree of interpenetrationis Z ) 2 (see Figure 5) and the classes of interpenetration areeither Ia or IIa. There are few exceptions: in particular we mustmention the case of the 103-srs net SAYMUB01, that has Z )18, by far the highest value ever found, and belongs to the rareClass IIIb.15 Other noteworthy species are XEBTIH, 66-dia withZ ) 11 and few net arrays belonging to the uncommon ClassIIIa: RASBOD, 66-neb, Z ) 8, HUXMUI and UDAYUT02,32.104-lcv, Z ) 6, BEQVUO, 65.8-cds, Z ) 4, JUTGOU andQUSMEW, 66-dia, Z ) 4.

The values of HBRI are in many cases >1, as discussedabove, showing that in hydrogen-bonded systems especially oftype AA, the single molecules tend to use all the possiblehydrogen bonds, according to the Donohue and Etter rules.16

In the following discussion, we will present the differenttopologies using various Schemes that show groups of structuresin order of increasing connectivity. As already mentioned, foreach Refcode we have also searched in the CSD for relatedstructures differing only in some ‘minor’ structural details

considered not influent on the hydrogen-bond patterns (i.e., adifferent halogen atom, a different -R similar substituent groupand so on). This was accomplished with the aim of possiblyfinding, by comparing the structures, elements useful for theirrationalization and for the crystal engineering of thesearchitectures.

Hydrogen-Bonds and Network Topologies. We have foundinterpenetrating nets mainly possessing common topologies(Figure 3). Nevertheless we have also observed some cases withquite rare topologies and discovered a few examples ofcompletely new ones.

3-c nets. Three-connected nets (only 16 cases) possess manydifferent topologies (see Table 1 and Scheme 2). Four nets oftype AA have the 4.142-dia-f topology using the molecularnodes, but all give 4-c nets of the 42.84-lvt topology withmolecular dimer nodes (ring synthon I). The most interestingis IBUXIN, which is 6-fold interpenetrated while the other three(AHEGOJ, IQAFEL, QECNAN) are only 2-fold interpenetrated.The authors gave a different description of IBUXIN taking intoaccount an intermolecular C-H · · ·O interaction but neglectingan N-H · · ·O one. By including these C-H · · ·O contacts also,a unique single 5-c net with a new topology is produced.

Drastic effects on the net topology are produced by the changeof a substituent in the molecular tecton, though the same localhydrogen-bond pattern (i.e., the system of hydrogen-bondsformed by a molecule) is maintained. This is the case ofQECNAN: by replacement of the phenyl group with a methylone we have the species NUJQOY with the same hydrogenbonds but exhibiting a 2D 3-c net, with the 63-hcb honeycombtopology here as brick-wall. Moreover, in KANVUR, a 2-fold6.102-pcu-h net (or a 64.82-nbo net considering dimer nodes),the substitution of the n-hexyl side chain by an i-propyl groupresults in KANWAY, which contains 1D polymers.

Figure 2. (top) Distribution of the net topologies within the 122structures; (bottom) distribution of the connectivity of the nodes (n-c).The table shows the occurrence for nets assembled by a single (TypeAA) or by different (Type AB) building blocks.

Figure 3. The most frequently observed nets (see also Figure 2).


The two well-known 3-c 103 topologies (103-srs and 103-ths) are present with four and two cases, respectively. Moreover,a novel 103 topology has been discovered in the 3-foldinterpenetrated KAPFIR (103-cds-3-Pnna; Vertex Symbol[10.10.103]). This new net has been found in a recent searchfor net relations by Blatov;10 it is interesting to note that thereare 27 known uniform nets with the Short Symbol 103 and 15have the same Vertex Symbol [10.10.103].

The 103-srs nets include the world record of interpenetration:the exceptional 18-fold SAYMUB01. Since the nets of thistopology are chiral it is of interest to establish the presence of

enantiomeric pairs. As we have previously suggested,2d in thepresence of such pairs the interpenetration class cannot be simplytranslational (Class I). Indeed SAYMUB01 contains nineenantiomeric pairs, ADENSL and NUZKAU 1 pair, whileTIPKIM contains two homochiral networks. In the latter casechoosing dimers (ring synthon X, see Figure 6) gives rise totwo translationally equivalent interpenetrating diamond nets.Indeed, the relationship between 66-dia and 103-srs nets is rathercommon for homomolecular hydrogen-bonded frameworks, asrecently found by Baburin and Blatov.14 The vertices of thediamond net occupy one-third of the edge centers in the 103-srs net (Figure 6).

Diamondoid Nets 66-dia. These networks are the mostnumerous ones also in hydrogen-bonded interpenetrated systems(38 cases), though their % distribution is lower than expected(see above). They show an interpenetration degree Z rangingfrom 2 to 11. With Z > 2 (17 cases illustrated in Scheme 3),the interpenetration is generated by pure translational symmetry(Class Ia) in all but two cases (JUTGOU and QUSMEW, Z )4, Class IIIa). In the 2-fold interpenetrated net arrays, Class Ia(10 cases) and Class IIa (11 cases) are almost equally populated.Noncentrosymmetric space groups are observed in 13 cases, aresult that can be of interest toward the achievement of acentriccrystal structures with promising NLO properties, as appearedin recent years.

The diamondoid net array with the highest interpenetrationdegree Z (11-fold, the current world record for 66-dia) isXEBTIH, a species that has been properly engineered usingtetrahedral nodes and linear spacers in the ratio 1:2. Ininterpenetrated MOFs the current upper limit is rep-resented by the 10-fold 66-dia network XISXAY,[Ag(dodecanedinitrile)2](NO3). Note that all the diamondoid netsof Class Ia show normal mode1a,2a,b of interpenetration exceptthe four cases with Z ) 5 (GEJVEW, JADMAD, XUVBAR,XUVBEV) and one with Z ) 8 (the silane analogous ofVOJFAB).

Wuest and co-workers have reported that tetrakis[4-(6-oxopyrid-2-yl)ethynylphenyl]methane gives hydrogen-bondedframeworks containing carboxylic acids as guests. The bis(bu-tyric acid) clathrate VOJFAB contains disordered guest mol-ecules and is a 7-fold diamondoid net array. Note that theanalogous silane species (not reported in CSD) is 8-foldinterpenetrated (but non-normal,1a,2a,b that is, not along one ofthe 2-fold axes of the adamantane cage). The related speciesVOJFEF contains propionic acid guest molecules, which formdirect hydrogen-bonds with the tecton thus preventing thepossibility of an extended hydrogen-bonded network.

It is worth mentioning the case of QUSMEW (a cyclictetracarboxylic acid monohydrate, 4-fold 66-dia, Class IIIa). Wehave decided to not include guest water molecules in ourtopological analysis since they are often disordered or not wellrefined, but in this species the water molecules interestingly jointhe 66-dia nets in pairs, thus resulting in a completely differentdescription of the supramolecular array, that is, a 2-fold ClassIIa interpenetrated 6-c net array with the 48.67-msw topology(see below the 6-c WUQYOW).

The substitution in TERRUD (N-acetyl-L-glutamic acid,3-fold 66-dia) of a -COOH group by a -CONH2 one gives aspecies (AGLUAM10), which has the possibility of an additionalNH · · ·OdC hydrogen bond; neglecting this rather long newcontact the net array remains 3-fold 66-dia, while taking it intoaccount a unique single 6-c new net (44.611) results, with a lowerHBRI of 8/6.

Figure 4. (top) Distribution by the node connectivity of single 3Dhomonuclear hydrogen-bonded nets from refs 13a and 13b. (bottom)Occurrence of infinite nets in MOFs and hydrogen-bonded frameworksdivided by dimensionality.

Figure 5. Distribution of the degree of interpenetration Z (n-f). Thetable shows the occurrence for dia nets and for the remainder.


The structure of (+)-pinoresinol contains a 3-fold 66-dia array(FAFXUF). It was interesting to analyze also the structure ofthe racemic form NELRUR that exhibits a different localhydrogen-bond pattern producing a system of square layers of44-sql topology. The molecular units are, in this case, flatter.Nitrilotriacetic acid (NTRTAC) is the second oldest exampleof recognized interpenetration (1967) but missing one subnet;it was classified as 2-fold instead of 3-fold. The oldest example(1947) is 2-fold -quinol QUOLSO (vide infra).

A number of 2-fold interpenetrated 66-dia net arrays showinteresting features (see Scheme 4); some of them are discussed

here, which change their topology by replacement of substituentsnot directly involved in the hydrogen-bond pattern.

In FEWSAC the substitution of the two methyl groups bychlorine atoms leads to FEWRUV, exhibiting a different localhydrogen-bond pattern that contains a highly distorted single65.8-cds network.

The modification of the side chain -CH2-COOH in TAQXAL(2-fold 66-dia) has drastic effects: with a -CH2-CH2-COOHelongated side chain (BIYRIK) the hydrogen-bond patternchanges, and the array results in 63-hcb layers (HBRI ) 4/3).With a -CH2-CH2-CONH2 chain (CIRYUK) we obtain again44-sql (HBRI ) 6/4), while with a -CH2-CH2-OH chain(DEFXOB) a 1D polymer is observed.

Other 4-c nets. Many important 4-c nets, different fromdiamondoid nets, are observed. Collectively, their number iscomparable with that of diamondoid nets (45 vs. 38 nets). Wehave the following net topologies: 14 of 65.8-cds, 11 of 42.84-lvt, 5 of 64.82-nbo, 4 of 43.62.8-gis, 3 of 32.104-lcv, 3 of 66-neb and 5 other nets with less common topologies. Curiously,some 4-c nets rather usual in other families of compounds, suchas 42.84-pts, are here lacking.2d

The numerous group of 65.8-cds nets (Scheme 5) shows amaximum Z value of 4 (BEQVUO, Class IIIa). The structureof 1,3-diamino-2,4,6-trinitrobenzene (DATNBZ) reveals a 2-fold65.8-cds net array that remains unchanged also in the isomorphic5-fluoro substituted species (BEWYOR). The high packingefficiency and crystal density observed for these compounds(and for related polynitro-organic compounds) were generallyascribed to efficient intermolecular packing arrangements, which

Scheme 2

Figure 6. Relationship between 66-dia (red) and 103-srs (blue) netsvia ring synthon X observed in TIPKIM.


limit the amount of free space in the unit cells, while thepossibility of interpenetration to fill voids was previously notconsidered.

The interesting species 4-carboxamido-1-cubanecarboxylicacid (JUNQIS) gives a 2-fold 65.8-cds net array (erroneouslyclassified by the authors as 64.82-nbo). Its bis(carboxamide)derivative (HIDTET) uses all its hydrogen-bond functionalities,so that each building block is linked to six other moleculesresulting in a novel single 6-c net of topology (44.610.8). The2-fold net observed for 2-aminoethene-1,1,2-tricarbonitrile(TAPZOA) was wrongly described as (non-“standard”) 103-ths, while following their proposed simplification it is 103-utp.

The structures of a series of p-alkylamido-substituted per-benzoic acids well illustrate the effects of the lengthening ofan alkyl side chain: p-acetamidoperbenzoic acid (ZUHHIT) andp-propanamidoperbenzoic acid (ZUHHOZ) give 3-fold 65.8-cds net arrays, but longer side chains (ZUHHUF, butanamido,and ZUHJAN, pentanamido) give simple almost flat 2D 44-sql.

Another numerous group of interpenetrated net arrays exhibitsthe 42.84-lvt topology (see Scheme 6). The lengthening of themolecular chain on passing from BOLNOF, 3,3′-(ethylenedi-imino)-bis(3-methyl-2-butanone oxime), to CEYSOO, 3,3′-(trimethylenedi-imino)-bis(3-methyl-2-butanone oxime), doesnot alter the topology and Z (both are 2-fold 42.84-lvt), but onlythe Class, from Ia to IIa.

A number of biimidazole and bipyrazole derivatives havebeen investigated because of their interesting hydrogen-bondedarchitectures (Scheme 6) that can be topologically described indifferent manners. While the parent 4,4′-biimidazole givessimple 2D 44-sql (KAMBEG) the methyl species 2,2′-dimethyl-4,4′-biimidazole (LEBKUZ) is a 2-fold interpenetrated 64.82-

nbo array and the ethyl species 2,2′-diethyl-4,4′-biimidazole(LEBLAG) forms a single 3D 65.8-cds net. In spite of thedifferent topologies, therefore, the “square-planar” local geom-etry of the nodes is always maintained. On choosing as analternative node the ring synthon VI in LEBKUZ, a 2-fold412.63-pcu net array is generated. Moreover, also the individual5-membered rings of the molecule can also be selected as 3-cnodes leading to the 6.102-pcu-h (LEBKUZ) and 103-ths(LEBLAG) topologies, respectively.

Also, the structure of the parent 4,4′-bipyrazole (UDAYIH)contains 2D 44-sql. The derivative 3,3′,5,5′-tetramethyl-4,4′-bipyrazole is known in many fascinating forms, with or withoutclathrate molecules. There are three polymorphs of the guest-free species (UDAYUT, UDAYUT01, UDAYUT02) exhibitingdifferent 3D networks, which are discussed later. Moreover, thetris(chloroform) clathrate (HUXMIW) is exceptional becauseit is a 4-fold interpenetrated 32.104-lcv array consisting of twononequivalent pairs of net arrays (2 + 2 interpenetration, ClassIIa + IIa). The methanol solvate species (HUXMUI) is of typeAB since the methanol molecules (3:1 ligand/methanol) areincluded in the network as spacers: the resulting system showsagain the 32.104-lcv topology but is 6-fold interpenetrated (ClassIIIa).

One of the older examples of well-characterized interpen-etrated supramolecular assemblies via hydrogen-bond bridgeswas the family of rhombohedral -quinol clathrates, all exhibit-ing the same structural type (see Figure 7). Also the guest freeform (HYQUIN05) was claimed to possess this structure, whichwe have classified as 2-fold 64.82-nbo, using as nodes the wholemolecules (the “standard” topology). However, here we have aclassical case of possible alternative topological descriptions,that can seem more natural: assuming the hexagonal synthons

Scheme 3


V as nodes we obtain the 412.63-pcu topology, or, otherwise, a3-c 6.102-pcu-h topology (pcu decorated by hexagons) can beenvisaged using as nodes the -OH groups. Quinol, moreover,gives also the R- and γ-forms that are considered later.

A series of structural investigations were devoted to thecharacterization of supramolecular arrays based on 2,7-dimethyltricyclo[4.3.1.13,8]undecane-syn-2,syn-7-diol and relatedspecies. These analyses are of great interest in the context of

Scheme 4

Scheme 5


crystal engineering: topological framework changes are observedupon variation of the clathrates and/or substituents.

The clathrates show three different structural situations:(a) 2-fold interpenetrated 43.62.8-gis net array in BUXRIV/

BUXRIV10[(diol).benzene],LORQUE[(diol)4.CH3CN],LORQOY[(diol).CH2Cl2], POLFIF [(diol)4.CS2], QULKOX

[(diol)4.cyclohexane], QULLAK [(diol)4.CHCl3], VUSYEN[(diol)4.1,2-dichlorobenzene];

(b) single 64.82-qtz net in BUXREV/BUXREV10 [(diol).ethylacetate], EDOLOY [(diol).t-butylcyclohexane], EDOLUE [(di-ol).cyclohexane], PAPSII [(diol).CCl4], PAPSOO [(diol).1,3-dibromopropane], PAPSUU [(diol).o-xilene], POKVUG[(diol).dibromodifluoromethane], QULKUD [(diol)3.fluorocyc-lohexane], QULLEO [(diol)2.(CHCl3)], VUSYIR [(diol)3.1,2-dichlorobenzene];

(c) 2D 44-sql in EQOPOP [(diol).propionic acid], EQOPUV[(diol).acetic acid], EQOQAC [(diol). 2-propanol], HIBGII[(diol).p-chlorophenol], HIBGOO [(diol).p-methoxyphenol],HIBGUU [(diol).p-hydroxythiophenol].

Also the guest-free species (SODVUC) is comprised of 2D44-sql.

Group (c) differs from the other two in that the clathratemolecules use their -OH functionalities to form direct hydrogenbonds with the diols that seem to prevent the formation of 3Darchitectures. In group (a) the 2-fold interpenetration is ac-companied by a lower content of guest molecules with respectto group (b) single nets. For example, compare QULLAK (2-fold 43.62.8-gis) and QULLEO (single 64.82-qtz), both CHCl3

clathrates but exhibiting (without guests) free voids of 13 and26%, respectively, and a double amount of guests in the second

Scheme 6

Figure 7. On the left, the network observed in -quinol HYQUIN05showing the hexameric synthon V (Scheme I) that maps onto 412.63-pcu. On the right, the three possible descriptions of a single net of the2-fold -quinol: “standard” 64.82-nbo (green) with the whole moleculeas 4-c node, ring-synthon net 412.63-pcu (red) with the centres of thehexagonal synthon as 6-c nodes and 6.102-pcu-h (blue) when theoxygens of the -OH groups are considered as 3-c nodes.


one. A single gismondine network (43.62.8-gis) as observed inthe 2-fold interpenetrated acetamidine (CALVAM) is shownin Figure 8.

The structure of (+/-)1,2-bis(3,4-dimethoxyphenyl)-1,2-ethanediol (HAGPUA) shows the unique case of a chiral 2-foldinterpenetrated 64.82-qtz network. A drastic change is observedin the structure of the meso-form (TABJEL) that containshydrogen-bonded 1D chains.

The list of interpenetrated 4-c nets includes also someexamples of quite unusual topology of great interest (Scheme7). This is the case of 66-neb, a rather elusive topology thatcan be confused with 66-dia, first mentioned as ”net 9” byO’Keeffe and Brese17 during an enumeration of uninodal 4-cnets, and later observed and correctly described by Ermer andEling18 in examining the hydrogen-bonded single supertetra-hedral network of ethanolamine (JAKKEL).19 The comparisonof 66-dia and 66-neb is shown in Figure 9; both nets have thesame Schläfli Symbol 66 but different Vertex Symbols([62.62.62.62.62.62]-dia; [6.6.6.62.62.62]-neb) and CoordinationSequences that differs from the third term (4,12,24,42 · · ·dia;4,12,27,50 · · ·neb). The left column of Figure 9 shows a cutextracted from 66-dia, a double adamantane cage (14 carbonatoms), called diamantane or also congressane (D3d symmetry),while the right column illustrates the single cage of 66-neb. Thisis a hypothetical pentacyclotetradecane cage [66] named “iso-diamantane” (D2 symmetry) by Ermer and Eling;18 it forms thenatural tiling of 66-neb, while the 66-dia natural tiling isconstructed of single [64] adamantane units.8 We have foundhere three examples of interpenetrated nets with this topology(RASBOD, JUKVOA, MIGRID) that was previously not seenby the authors (or confused with 66-dia). RASBOD (Type AB)is particularly noteworthy in that it is 8-fold interpenetrated ofClass IIIa.

The unusual topology (42.84)-uoc is observed in two cases.DASDIL contains two interpenetrated nets of the same topologybut not symmetry related; that is, this is a rare case of (1 + 1)nonequivalent interpenetration.2e The molecule 17R-phenyl-androst-5-ene-3,17-diol (CAXROI) gives a 3-fold (42.84)-uoc net array, but the replacement of the phenyl with the benzylgroup results in HAVFOZ which forms 2D 44-sql.

Finally, compound 4-hydroxybenzaldehyde(4-nitrophenyl)-hydrazone (ITUXIE) crystallizes with two independent mol-

ecules, each of which is an independent node; the array is a2-fold binodal (65.8)(66)-sqc187 network.9 The same moleculewith 1,4-dioxane solvate (ITUXEA) gives 2D 63-hcb layersusing dioxane as spacer.

Higher Connectivities. Here we briefly discuss interpenetrat-ing networks with node connectivities >4, that is, in the range5–8. These nets are rare (only 10 cases, see Scheme 7 for 5-cand Scheme 8 for the remainder), a feature that is peculiar ofinterpenetrating hydrogen-bonded networks, different fromMOFs and inorganic frames where the 6-c primitive cubic412.63-pcu (R-Po) topology is the second one after 66-dia (17.3%in MOFs and 18.8% in inorganic nets).

There are five examples of 412.63-pcu net arrays, all 2-foldinterpenetrated. In the pair UJOFEE, tetrakis(4-hydroxyphenyl)-methane, and UJOFII, tetrakis(4-hydroxyphenyl)silane, the samearrays are observed, though they are not isomorphic. ForUJOFII, one hydrogen-bond interaction was missed by theauthors, with the consequence that the net was described as 4-cinstead of 6-c 412.63-pcu.

Wuest and co-workers have reported the structure of 3,3,9,9-tetrakis(4-(2,6-diaminotriazen-4-yl)benzyl)-2,4,8,10-tetraoxospiro[5.5]undecane (WUQYOW), which was incorrectlydescribed as an 8-fold 66-dia (that should belong to Class IIIa,4*2) because an important additional hydrogen-bond contactwas neglected. Including these interactions the network becomes6-c 2-fold interpenetrated of Class IIa and belongs to a new(48.67) topology that we name bp1. With all the hydrogen bondsthis compound is the one with the highest HBRI (of 16/6 )2.666). WUCYUC is a different clathrate, isomorphic withWUQYOW. The nature of (48.67)-bp1 has suggested to us thepossible existence of a whole new series of uninodal self-catenated 6-c nets derived from interpenetrated 66-dia nets: whenthe parent n-fold 66-dia net arrays are of Class Ia, by connectingthe 4-c nodes along the unique full interpenetration vector (FIV)we obtain single nets all having the same Schlafli Symbol (48.67)whichever the number of nets in the array (but topologicallydistinct by, e.g., Coordination Sequence). We can apply the sameprocedure to n-fold 66-dia net arrays of Class IIIa by connectingin this case the 4-c nodes along the translation interpenetrationvector (TIV). Again we obtain (48.67) 6-c nets but now the arrayis interpenetrated of Class IIa (retaining the original nontrans-lational symmetry operation). This is what observed for WU-QYOW [from 8-fold IIIa to 2-fold (48.67)-bp1] (see Figure 10)and for the previously mentioned QUSMEW [from 4-fold IIIato 2-fold (48.67)-msw, when the solvate water molecule isconsidered].

The highest connectivity is present in the unique 8-c 2-foldinterpenetrated species BAWJUF, which shows the (424.64)-bcu topology.

Mixed Nodes. Obviously, though not strictly necessarily,none of these species (13 cases) is of the type AA. Differentmolecular nodes, with different hydrogen-bonding requirements,favor the formation of mixed nodes networks. The most commonones are 3,4-c (see Scheme 9). It is noteworthy that four of thefive new nets are in this group and that the net (83)2(85.10)-bp2 has been recently observed as single net in a leadcoordination polymer.20

Hydrogen-Bonded Nets and Interpenetration. Our resultsmay provide new information for the rationalization of thephenomenon of interpenetration (class and degree) in networksbased on similar tectons and exhibiting the same topology.Different Z values (or, at least, different classes) could, inprinciple, be produced in type AA species by one (or more) ofthe following factors: (a) effects of different guests; (b) atom

Figure 8. On top the network observed in acetamidine (CALVAM)showing the three possible alternative description: 4-c “standard”topology (green), 4-c rhombic ring synthon (red) and 3-c when themolecule is considered as two 3-c nodes (blue). Below the three netsgis (green), lvt (red), and lvt-a (blue) derived from the alternativedescriptions.


or group substitution in the node leading to variated dimensionsof the tecton; (c) different length of side chains bearing thehydrogen-bond donors and/or acceptors.

Examination of the networks listed in Table 1 reveals some

interesting observations. The effect of changing the guestmolecules has some influence in the family of 2-fold 66-dianets assembled from 2,6-dimethylideneadamantane-1,3,5,7-tetracarboxylic acid (see Scheme 4). While Z remains the same,some (VOBFAT, VOBFEX, VOBFIB) belong to Class IIa, withthe two equivalent nets generated by an inversion center, others(VOBFOH, VOBFUN) belong to the same Class IIa but with a2-fold axis as symmetry operation, and one (VOBGAU) is ofClass Ia. On the other hand, guest substitution has differentconsequences in the family of 2-fold 66-dia networks INUJUW,INUKAD, and YINJOU: they represent a case of adaptiveporosity and contain the tecton tetrakis(1,2-dihydro-2-oxo-5-pyridyl)silane together with different carboxylic acids solvatesthat produce expansion/compression of the frames.21 All thenet arrays belong to Class Ia and the change of guests impliesa variation of the interpenetration vector (coincident with the ccrystallographic axis). Curiously, the related species YINJUA,with Sn instead of Si and containing clathrate valeric acid, formsa different hydrogen-bond pattern resulting in a 6-c single 412.63-pcu net.

Substitution of the central atom in the node of VOJFAB (Siin place of C) leads to a greater Z value (from 7 to 8), as alreadymentioned. At difference from this case in the pair of net arraysXUVBAR/XUVBEV the replacement of C by Si at the nodesdoes not influence the degree of interpenetration (both are 5-fold66-dia, Class Ia).

It is of interest in the context of crystal engineering tocompare the structure of -quinol (HYQUIN05, see above andFigures 1 and 7 and Scheme 6) with that of the related lineardiphenolic species 2,2′′ ,6,6′′ -tetramethyl-4,4′′ -terphenyldiol

Scheme 7

Figure 9. Two perpendicular views of the different cages made of 14nodes observed in the uniform nets 66-dia and 66-neb.


(KAPVIH). The two species share the same 64.82-nbo topology,but the increased length of the tecton in KAPVIH causes achange of the interpenetration degree from 2- to 4-fold (bothspecies are of Class Ia).

The effect of side chains lengthening on interpenetration hasbeen already observed in the pair BOLNOF/CEYSOO (seeabove and Scheme 6): both are 2-fold 42.84-lvt, but the Classpasses from Ia to IIa.

A major effect is observed in the pair methanetetracetic acid(GESTAZ) and methanetetrapropionic acid (JADMAD): bothare 66-dia Class Ia, but the former is 3-fold while the latter is5-fold interpenetrated.

On the other hand, no effects on interpenetration are observedon comparing the 2-fold 66-dia net arrays, Class Ia, of6-methylisocytosine-5-acetic acid (ZERMUE) and 6-methyl-isocytosine-5-propionic acid (ZERNEP), though they showsomewhat different local hydrogen-bond patterns (see Scheme4 bottom).

These observations show how difficult it is, given a certaintopology, to predict the extent of the phenomenon of interpen-etration, even when we compare two closely related species.

Hydrogen-Bonded Nets and Crystal Engineering. Crystalengineering concerns the structural control of the outcomingarchitectures from a certain planned self-assembly process.22

However the arrays of type AA obtained from the self-assemblyof organic molecules are difficult to control in their final result.A major control seems achievable when the deliberate buildingof type AB species (presumably nodes+spacers) is attemptedusing basic concepts that are the same for the construction ofMOFs and of hydrogen-bonded arrays. A suitable building blockof selected geometry is chosen as a node for a specific targetnetwork, together with proper spacer molecules to join the nodes.Unfortunately, this does not seem to be sufficient to obtain thetarget architecture. With type AA species, on the other hand,all the information on the resulting net should be embedded inthe structure of the tecton, but the passage from tecton to synthonand then to the overall net is still far from being wellunderstood.22 Conflicting factors for any strategy of this typeare the concurrent possible alternatives arising from polymor-phism and supramolecular isomerism (see below). Indeed, weprobably prefer to ignore that there is a large variety oftopologies associated with each selection of the (planned)building blocks, so that, for instance, we expect that tetrahedralnodes and linear spacers in the proper ratio should always resultin superdiamond networks. The occurrence of alternative nets(see above the case of the 66-neb topology) is therefore usuallyoverlooked. Factors orienting the topology of the assembly arepoorly investigated. Moreover, the ambiguity associated withthe possible control of the degree of interpenetration has alreadybeen described above. From the perspective of getting betterinsight we suggest that the unique possibility seems to inves-tigate in a systematic fashion the self-assembly processes uponvariation of the reaction conditions. At present we do not havetrue answers to questions like “why a certain topology?” and“why interpenetration?”

As to the geometry of the tecton in orienting the topology ofthe resulting networks we have already shown (see above) thatsmall changes in the molecule can have drastic topological

Scheme 8

Figure 10. The generation of the new 6-c (48.67)-bp1 net from 4-foldinterpenetrated 66-dia nets.


effects. Nevertheless, with a certain optimism, we can outlinehere some trends.

(a) We observe that the local geometry may be “foreseen”by considering the structure of molecules. Thus the mostfrequent 4-c topologies can be divided in two classes lookingat the local geometries at the node and comparing it with theones for the idealized nets: tetrahedral (66-dia, 43.62.8-gis, 66-neb) and rectangular (65.8-cds, 42.84-lvt, 64.82-nbo). Thus, in66-dia nets there are tetrahedral molecular centers, and in netswith rectangular coordination there are planar molecules (oftenwith conjugated π-electronic systems). We may expect with highprobability that molecules with a rectangular hydrogen-bondenvironment will give one of the three possible rectangular nets.

(b) Some relevance may be attributed to the fact that groupsof networks with the same “standard” topologies can also bedescribed in the same way using their “ring synthon nets”, asin the case of many molecular 42.84-lvt nets that contain 66-dia “ring synthons nets”. Note that the “standard” and “ringsynthon net” topologies are interrelated and match each other(Table 1); starting from the “standard” net one can anticipatepossible topologies of “ring synthon nets”.

(c) Another aspect that has been checked here concerns thesubstitution in a molecule of a bound group not directly involvedin hydrogen-bonding with a different one of similar volume;

the exchange is not expected to influence the net topology. Thisis true, for example, in the pair BUXRIV/WOYLEB byreplacement of a -CH2- moiety by a -S- atom (both net arraysare 2-fold 43.62.8-gis). On the other hand, in a family ofaminophenols (ENANIQ/ENAMAD) the effect of substitutionof a -CH2- group by an -S- atom shows a complete structuraltransformation from 2-fold 65.8-cds to a 2D 44-sql species.

Hydrogen-Bonded Nets, Polymorphism, and Supra-molecular Isomerism. In the self-assembly of hydrogen-bondedorganic supramolecular arrays and in the crystal engineeringstrategies for the construction of specific networks we arecontinuously faced with the phenomena of polymorphism andsupramolecular isomerism, that, together with the unpredictableevent of interpenetration or other types of entanglements,1,2 canrepresent obstacles to our planning ability.

Polymorphism appears when the same substance exhibitsdifferent crystal packing arrangements.23 Supramolecular isom-erism, on the other hand, concerns the possible existence ofmore than one network superstructure for the same molecularbuilding blocks; it has been introduced in the context ofcoordination polymers24 but applies as well to all other modularextended arrays. So, the former phenomenon deals with crystals,while the second one deals with networks and their topologies.

Scheme 9


Polymorphs can be always described also as supramolecularisomers but not vice versa. Supramolecular isomerism can applytherefore to nets of the same composition but with differenttopologies because of different guests (solvates or pseudopoly-morphs). Moreover this phenomenon can include differentindependent isomeric nets that are found together in the samecrystal, as observed in some MOFs.24b,c

The analysis of polymorphism and supramolecular isomerismcan be carried out using the network topological approach, thatproduces an useful categorization and creates opportunities forsystematic structure–property studies.

We have examined for all the interpenetrated hydrogen-bonded nets the possible existence of polymorphs. The resultsare listed in Table 2. We can compare the polymorph structuresconsidering the changes in topology/node connectivity, as aconsequence of possible variations in the hydrogen-bondpatterns.

In the case of SAYNAI01/SAYNAI we pass from 3-foldinterpenetrated 82.10-lig to a single 103-ths net; both topologiesare 3-c and the local hydrogen-bond pattern remains almost thesame, forming a ring synthon I that is flat in the former specieswhile rather folded in the second one (“bowl shaped” accordingto the authors).

The three polymorphs of 3,3′,5,5′-tetramethyl-4,4′-bipyra-zolyl, UDAYUT01 (R form), UDAYUT ( form), and UD-AYUT02 (γ form), give networks with the same connectivity(4-c) but different topologies: single 65.8-cds, single 64.82-qtz,and 6-fold 32.104-lcv (see Figure 11), respectively. The mol-ecules form similar hydrogen bonds that result in “chainsynthons” in the two former cases while in UDAYUT02, ringsynthons II are present. The analysis of N-C-C-N torsionangles shows similar values in the R and noninterpenetratedforms but quite different in the γ one.

In the case of KAPVIH/KAPVIH01, we observe two 4-cnetworks: 4-fold 64.82-nbo in the former one vs 44-sql in thesecond one, that can be related to the formation of differentsynthons (ring synthon V and chain, respectively).

On the other hand, in the pair BASVUM01/BASVUM thedifferent topologies (2-fold 64.82-nbo vs. 44-sql) seem not tobe related to different hydrogen-bond patterns but rather to moresubtle factors, that is, to the relative orientations of adjacentmolecules, as discussed by the authors.

We have already discussed the structure of -quinol in theguest-free HYQUIN05 (2-fold 64.82-nbo). Two polymorphs (R,HYQUIN02, and γ, HYQUIN) are also known. However,

though all the three species are 4-c, the nets are different: thetopology of HYQUIN02 is a novel 3D trinodal net of topology(62.84)(62.84)(64.82) and HYQUIN gives 44-sql. Indeed, the samekind of hydrogen bonds are present but different synthons areformed in the three cases.

All the above examples are of type AA, but there are alsotwo cases of polymorphs that involve the assembly of differentmolecular building blocks. In the pair SAYMUB01/SAYMUB,of type AB (with only A nodes), both polymorphs are 3-c, but

Table 2. True Polymorphs of Interpenetrated Nets

Refcode topology C.P.a crystallization interconversion

SAYNAI01 ( tetragonal) lig 3-f Y from dichloromethane R interconverts to at 368.8 KSAYNAI (R orthorhombic) ths singleSAYMUB01 (orthorhombic) srs 18-f Y from DMSOSAYMUB (monoclinic) hcb 3-fUDAYUT02 (γ tetragonal) lcv 6-f hydrothermal conditionsUDAYUT01(R monoclinic) cds single N from hot waterUDAYUT ( hexagonal) qtz single from acetonitrileKAPVIH (compound 1a) nbo 4-f Y from ethyl acetateKAPVIH01 (compound 1b) sql layerBASVUM01(orange trigonal) nbo 2-f Y from ethyl acetate yellow interconverts to orange in the range

25–125 °CBASVUM (yellow monocl.) sql layerHYQUIN02 (R) 4-c trinodal N sublimation γ and spontaneously convert to RHYQUIN (γ) sql layer sublimation or rapid evaporation

at RT from ethyl etherHYQUIN05 () nbo 2-f n-octane (air free ethanol)APYRDN (R, RT) bp5 2-f N acetonitrile at RT phase transition at 290 KAPYRDN01 (, low T) bp4 2-f acetonitrile at 283 K

a C.P. ) concomitant polymorphs.

Figure 11. On top, the network observed in UDAYUT02 (γ form)and in the bottom, the three possible alternative descriptions: 4-c“standard” topology 32.104-lcv (green), 3-c 103-srs rhombic ringsynthon II (Scheme 1) (red) and 3-c 3.202-srs-a (blue) when themolecule is considered as two 3-c nodes.


only SAYMUB01 is 3D (the unique 18-fold 103-srs) whileSAYMUB contains 2D 63-hcb layers that are 3-fold interpen-etrated in a parallel fashion. Both show the same hydrogen-bond pattern, with single bonds of the -COOH groups of thetrimesic acid to the 4,4′-bispyridylethane spacers. The differenceconsists in the relative rotation about the hydrogen-bonds ofthe adjacent nodes, that is, the molecules of the acid give thethree dihedral angles for C-C-OH · · ·N that deviate consider-ably from 180° (150°-170°) only for the 3D derivative.

Finally, we consider the case of APYRDN/APYRDN01, theR- and -forms of 4-aminopyridin hemiperchlorate, respectively,that are both included in our list of interpenetrated nets. Thetwo species are of type ABC, with three distinct nodes, that is,the 4-aminopyridin molecule, its protonated form and theperchlorate anion. In Scheme 9 we show only the APYRDN01polymorph, the second one (APYRDN) differing only in theinteractions of the perchlorate anion that uses three out of thefour oxygen atoms for networking but gives a bifurcatedH-bond. Thus the ClO4

- anions are 4-c nodes in both poly-morphs but originate different H-bonded patterns and different(3,4)-trinodal topologies with symbols: (4.6.83.10)(4.6.8)(6.82)-bp5 for APYRDN and (83)(83)(86)-bp4 for APYRDN01. Bothcompounds can be alternatively described considering theresonance hydrogen-bond pyridine-pyridinium dimer as node.

In summary, different polymorphs can be originated in somecases by variated hydrogen-bond patterns with different syn-thons, but can be observed also in the presence of almostidentical hydrogen-bond patterns because of different spatialorientations of adjacent molecules (tectons), especially whenthese are not joined via the more rigid ring synthons. Given acertain environment of the nodes (tetrahedral, square-planar, etc.)we must remember that many alternative topologies are alwayspossible.

Preliminary examination of the interaction energies with thePIXEL method23b,c of three couples of polymorphs (SAYNAI/01, KAPVIH/01, BASVUM/01) shows that the contribution ofthe Coulumbic term (that include hydrogen bonds) is alwayson the same scale as the dispersion terms from the nearestmolecules, indicating that the interpenetration phenomena cannotbe distinguished on an energy basis. The dispersion interactionsconnect all the subnets into a single one. On the other hand,the different dimensionality 2D vs 3D can be appreciated.

As to supramolecular isomerism, we can cite many examplesthat have been already mentioned, like the case of the familyof clathrates of 2,7-dimethyltricyclo[4.3.1.13,8]undecane-syn-2,syn-7-diol. We have above-described their distinct guest-induced topologies, as, for instance, in the pair QULLAK (2-fold 43.62.8-gis) and QULLEO (single 64.82-qtz) containingCHCl3 solvated molecules in different amounts. Moreover, wecan associate to the three just described guest-free polymorphsof 3,3′,5,5′-tetramethyl-4,4′-bipyrazolyl UDAYUT, UDAYUT01,and UDAYUT02, also the tris(chloroform) clathrate HUXMIW(2 + 2 interpenetrated 32.104-lcv) that can be considered asupramolecular isomer of all three.

Conclusions

The use of the TOPOS package for the analysis of interpen-etrating 3D hydrogen-bonded networks in CSD has produced acomprehensive list of 122 distinct entangled architectures.Interpenetration was previously not seen in most (71%) of thelisted species that exhibit a variety of topological types, someof which are unprecedented. The importance of describing theextended systems assembled with hydrogen-bonds in terms ofthe resulting overall array has been here emphasized to contrast

the attention often devoted only to the first molecular environ-ments. The distribution of the topologies is rather different fromwhat is observed in other classes of interpenetrated materials(such as coordination and inorganic networks). The results wereanalyzed to search for factors influencing the topologies, thedegree of interpenetration, and the phenomena of polymorphismand supramolecular isomerism.

Acknowledgment. L.C., G.C., and D.M.P. thank MIUR forfinancing the PRIN 2006–2007 “POLYM2006: Innovativeexperimental and theoretical methods for the study of crystalpolymorphism: a multidisciplinary approach.”

References

(1) (a) Batten, S. R.; Robson, R. Angew. Chem., Int. Ed. 1998, 37, 1460.(b) Robson, R. J. Chem. Soc., Dalton Trans. 2000, 3735. (c) Batten,S. R. Curr. Opin. Solid State. Mater. Sci. 2001, 5, 107. (d) Carlucci,L.; Ciani, G.; Proserpio, D. M. Coord. Chem. ReV. 2003, 246, 247.(e) Carlucci, L.; Ciani, G.; Proserpio D. M. Networks, Topologies,and Entanglements. In Making Crystals by Design - Methods,Techniques and Applications; Braga D., Grepioni G., Eds.; Wiley-VCH: Weinheim,2007; Chapter 1.3.

(2) (a) Batten, S. R. CrystEngComm 2001, 3, 67. (b) Carlucci, L.; Ciani,C.; Proserpio, D. M.; Rizzato, S. Chem. Eur. J. 2002, 8, 1520. (c)Carlucci, L.; Ciani, C.; Proserpio, D. M. CrystEngComm 2003, 5,269. (d) Blatov, V. A.; Carlucci, L.; Ciani, G.; Proserpio, D. M.CrystEngComm 2004, 6, 377. (e) Baburin, I.; Blatov, V. A.; Carlucci,L.; Ciani, G.; Proserpio, D. M. J. Solid State Chem. 2005, 178, 2452.(f) Koch, E.; Fischer, W.; Sowa, H. Acta Crystallogr. 2006, A62,152.

(3) (a) Vangala, V. R.; Bhogala, B. R.; Dey, A.; Desiraju, G. R.; Broder,C. K.; Smith, P. S.; Mondal, R.; Howard, J. A. K.; Wilson, C. C.J. Am. Chem. Soc. 2003, 125, 14495. (b) Desiraju, G. R., Ed. CrystalDesign: Structure and Function - PerspectiVe in SupramolecularChemistry; Wiley: New York, 2003; Vol. 7. (c) Desiraju, G. R.Angew. Chem., Int. Ed. 1995, 34, 2311. (d) Krische, M. J.; Lehn,J.-M. Struct. Bonding (Berlin) 2000, 96, 3. (e) Burrows, A. D. Struct.Bonding (Berlin) 2004, 108, 55.

(4) (a) Wells, A. F. Structural Inorganic Chemistry, 5th ed.; OxfordUniversity Press: Oxford, 1984. (b) Wells, A. F. Three-DimensionalNets and Polyhedra; Wiley: New York, 1977. (c) Wells, A. F. FurtherStudies of Three-Dimensional Nets; American CrystallographicAssociation: Pittsburgh, PA, 1979; Monograph 8. (d) O’Keeffe, M.Hyde, B. G. Crystal Structures I: Patterns and Symmetry; Mineral.Soc. Am.: Washington, DC, 1996. (e) O’Keeffe, M.; Eddaoudi, M.;Li, H.; Reineke, T.; Yaghi, O. M. J. Solid State Chem. 2000, 152, 3.(f) Yaghi, O. M.; O’Keeffe, M.; Ockwig, N. W.; Chae, H. K.;Eddaoudi, M.; Kim, J. Nature 2003, 423, 705.

(5) http://www.topos.ssu.samara.ru; Blatov, V. A IUCr CompCommNewsletter 2006, 7, 4.

(6) (a) Jeffrey, G. A. An Introduction to Hydrogen Bonding; OxfordUniversity Press: Oxford,1997. (b) Steiner, T Angew. Chem., Int.Ed. 2002, 41, 48.

(7) The authors are grateful to W. D. S. Motherwell for extracting thisinformation from CSD.

(8) (a) Delgado-Friedrichs, O.; O’Keeffe, M.; Yaghi, O. M. ActaCrystallogr. 2003, A59, 22. (b) Delgado-Friedrichs, O.; O’Keeffe,M.; Yaghi, O. M. Acta Crystallogr. 2003, A59, 515. (c) Ockwig,N. W.; Delgado-Friedrichs, O.; O’Keeffe, M.; Yaghi, O. M. Acc.Chem. Res. 2005, 38, 176. (d) Delgado-Friedrichs, O.; Foster, M. D.;O’Keeffe, M.; Proserpio, D. M.; Treacy, M. M. J.; Yaghi, O. M. J.Solid State Chem. 2005, 178, 2533. (e) Delgado-Friedrichs, O.;O’Keeffe, M.; Yaghi, O. M. Phys. Chem. Chem. Phys. 2007, 9, 1035.

(9) Hyde, S. T.; Delgado-Friedrichs, O.; Ramsden, S. J.; Robins, V. SolidState Sci. 2006, 8, 740.

(10) Blatov, V. A. Acta Crystallogr. 2007, A63, 329.(11) Öhrström, L.; Larsson, K. Molecule-Based Materials: The Structural

Network Approach; Elsevier: Amsterdam, 2005.(12) (a) Kuleshova, L. N.; Zorky, P. M. Acta Crystallogr. 1980, B36,

2113. (b) Zorky, P. M.; Kuleshova, L. N. Zh. Strukt. Khim. 1980,22, 153.

(13) (a) Baburin, I.; Blatov, V. A. Acta Crystallogr. 2007, B63, 791. (b)Baburin, I. Z. Kristallogr., accepted for publication. The list of therecognized single hydrogen-bonded nets with REFCODE describedin the two papers is available at http://www.topos.ssu.samara.ru.


(14) Remember that only topologies for nets of molecular centroids, notsupramolecular synthons, are considered here. Note that, on the otherhand, in the literature many net topologies were attributed selectingas nodes the centers of supramolecular synthons [e.g., LUVPUN wasdescribed as 66-dia (Z ) 2) using the tetrameric ring synthons III,but the “standard” topology of the molecular net is 42.84-lvt (Z )2)].

(15) Note that in 2e this possible value for Class IIIb was passed; it maybe obtained as a product of permitted values Z ) 9 and Z ) 2 forClasses Ib and IIa, respectively.

(16) (a) Donohue, J. J. Phys. Chem. 1952, 56, 502. (b) Etter, M. C. J.Phys. Chem. 1991, 95, 4601. (c) Etter, M. C. Acc. Chem. Res. 1990,23, 120.

(17) O’Keeffe, M.; Brese, N. E. Acta Crystallogr. 1992, A48, 663.(18) Ermer, O.; Eling, A. J. Chem. Soc. Perkin Trans. 2 1994, 925. The

authors considered the N and O atoms of ethanolamine as the nodesof the net. In our ”standard” representation the whole molecule is6-connected and the single net 48.66.8-rob.

(19) A MOF example of single 66-neb has been reported for some cobaltimidazolates EQOBUH, EQOCES, EQOCIW in Tian, Y.-Q.; Cai,C.-X.; Ren, X.-M.; Duan, C.-Y.; Xu, Y.; Gao, S.; You, X.-Z. Chem.Eur. J. 2003, 9, 5673.

(20) Yang, J.; Li, G.-D.; Cao, J.-J.; Yue, Q.; Li, G.-H.; Chen, J.-S. Chem.Eur. J. 2007, 13, 3248.

(21) Trolliet, C.; Poulet, G.; Tuel, A.; Wuest, J. D.; Sautet, P. J. Am.Chem. Soc. 2007, 129, 3621.

(22) Desiraju, G. R. Angew. Chem., Int. Ed. 2007, 46, 8342.(23) (a) Bernstein, J. Polymorphism in Molecular Crystals; Oxford

University Press: Oxford, 2002. (b) Gavezzotti, A. J. Pharm. Sci.2007, 96, 2232. (c) Gavezzotti, A Molecular Aggregation, StructureAnalysis and Molecular Simulation of Crystals and Liquids; OxfordUniversity Press: Oxford, 2006.

(24) (a) Moulton, B.; Zaworotko, M. J. Chem. ReV. 2001, 101, 1629. (b)Carlucci, L.; Ciani, G.; Proserpio, D. M.; Spadacini, L. CrystEng-Comm 2004, 6, 96. (c) Carlucci, L.; Ciani, G.; Proserpio, D. M. Chem.Commun. 2004, 380.

(25) AGLUAM10. Narasimhamurthy, M. R.; Venkatesam, K.; Winkler,F. J. Chem. Soc., Perkin Trans. 1976, 2, 768.

(26) ADENSL. Langer, V.; Huml, K. Acta Crystallogr. 1978, B34, 1157.(27) AHEGOJ. Lynch, D. E.; Mcclenaghan, I.; Light, M. E.; Coles, S. J.

Cryst. Eng. 2002, 5, 79.(28) APYRDN. Roziere, J.; Williams, J. M.; Grech, E.; Malarski, Z.;

Sobczyk, L. J. Chem. Phys. 1980, 72, 6117.(29) APYRDN01. Teulon, P.; Delaplane, R. G.; Olovsson, I.; Roziere, J.

Acta Crystallogr. 1985, C41, 479.(30) BASVUM-BASVUM01. Mann, B. J.; Duesler, E. N.; Paul, I. C.;

Curtin, D. Y. J. Chem. Soc. Perkin Trans. 2 1981, 1577.(31) BAWJUF. Shirakawa, M.; Kawano, S.; Fujita, N.; Sada, K.; Shinkai,

S. J. Org. Chem. 2003, 68, 5037.(32) BAXKIV. Ma, B.-Q.; Sun, H.-L.; Gao, S. Chem. Commun. 2003,

2164.(33) BEQVUO. Wheatley, P. S.; Lough, A. J.; Ferguson, G.; Glidewell,

C. Acta Crystallogr. 1999, C55, 1486.(34) BERCUW. Stoeckli-Evans, H. Acta Crystallogr. 1982, B38, 1614.(35) BEWYOR. Ammon, H. L.; Bhattacharjee, S. K.; Holden, J. R. Acta

Crystallogr. 1982, B38, 1851.(36) BICZIX. Arulsamy, N.; Bohle, D. S.; Butikofer, J. L.; Stephens,

P. W.; Yee, G. T. Chem. Commun. 2004, 1856.(37) BIYRIK. Fujita, S.; Takenaka, A.; Sasada, Y. Acta Crystallogr. 1982,

B38, 2936.(38) BOLNOF. Mazhar-ul-Haque; Hussain, M. S. Acta Crystallogr. 1983,

C39, 292.(39) BOLZIL. Kresge, A. J.; Lough, A. J.; Popik, V. V. Acta Crystallogr.

1999, C55, IUC9900140.(40) BUSPAG. Chan, T.-L.; Mak, T. C. W. J. Chem. Soc., Perkin Trans.

1983, 2, 777.(41) BUXRIV. Bishop, R.; Dance, I. G.; Hawkins, S. C. Chem. Commun.

1983, 889.(42) BUXRIV10. Hawkins, S. C.; Bishop, R.; Dance, I. G.; Lipari, T.;

Craig, D. C.; Scudder, M. L. J. Chem. Soc. Perkin Trans. 2 1993,1729.

(43) CALVAM. Norrestam, R.; Mertz, S.; Crossland, I. Acta Crystallogr.1983, C39, 1554.

(44) CAXROI. Weeks, C. M.; Strong, P. D.; Duax, W. L.; Vickery, L. E.Acta Crystallogr. 1983, C39, 1698.

(45) CEYSOO. Hussain, M. S.; Ul-Haque, M.; Ahmad, J. Acta Crystallogr.1984, C40, 813.

(46) CINMER. Takusagawa, F.; Hirotsu, K.; Shimada, A. Bull. Chem.Soc. Jpn. 1973, 46, 2669.

(47) CIRYUX. Fujita, S.; Takenaka, A.; Sasada, Y. Acta Crystallogr.,Sect. C 1984, 40, 1605.

(48) CUTYEV. Gregson, R. M.; Glidewell, C.; Ferguson, G.; Lough, A. J.Acta Crystallogr. 2000, B56, 39.

(49) CYANAM01. Denner, L.; Luger, P.; Buschmann, J. Acta Crystallogr.1988, C44, 1979.

(50) DACYEL. Ammon, H. L.; Prasad, S. M. Acta Crystallogr. 1985,C41, 921.

(51) DASDIL. Jones, I. W.; Monguchi, Y.; Dawson, A.; Carducci, M. D.;Mash, E. A. Org. Lett. 2005, 7, 2841.

(52) DATNBZ. Holden, J. R. Acta Crystallogr. 1967, 22, 545.(53) DEFXOB. Shibata, M.; Takenaka, A.; Sasada, Y. Acta Crystallogr.

1985, C41, 1499.(54) DOVSUC. Nagai, M.; Nagumo, S.; Lee, S.; Eguchi, I.; Kawai, K.

Chem. Pharm. Bull. 1986, 34, 1.(55) EDOLOY-EDOLUE. Alshahateet, S. F.; Bishop, R.; Craig, D. C.;

Scudder, M. L. CrystEngComm 2002, 4, 42.(56) EJUZOY. Bhogala, B. R.; Nangia, A. Cryst. Growth Des. 2003, 3,

547.(57) ENANIQ. Vangala, V. R.; Bhogala, B. R.; Dey, A.; Desiraju, G. R.;

Broder, C. K.; Smith, P. S.; Mondal, R.; Howard, J. A. K.; Wilson,C. C. J. Am. Chem. Soc. 2003, 125, 14495.

(58) EQOPOP- EQOPUV- EQOQAC. Alshahateet, S. F.; Nakano, K.;Bishop, R.; Craig, D. C.; Harris, K. D. M.; Scudder, M. L.CrystEngComm 2004, 6, 5.

(59) ETIGAP. Zhang, X.-L.; Chen, X.-M.; Ng, S. W. Acta Crystallogr.2004, E60, o453.

(60) FAFXUF. Lundquist, K.; Stomberg, R. Holzforschung 1988, 42, 375.(61) FAXHOB01. Youngs, W. J.; Hauer, C. R.; King, G. S.; McCool,

E. L.; Euler, W. B.; Ferrara, J. D. J. Am. Chem. Soc. 1987, 109,5760.

(62) FEWSAC. Hirano, S.; Toyota, S.; Toda, F. Chem. Commun. 2005,643.

(63) FEWRUV. Hirano, S.; Toyota, S.; Toda, F. Chem. Commun. 2005,643.

(64) GEJVEW. Ermer, O. J. Am. Chem. Soc. 1988, 110, 3747.(65) GESTAZ. Ermer, O.; Eling, A. Angew. Chem., Int. Ed. Engl. 1988,

27, 829.(66) GIMSIE. Ermer, O.; Lindenberg, L. HelV. Chim. Acta 1988, 71, 1084.(67) HAGPUA. Karlsson, O.; Lundquist, K.; Stomberg, R. Acta Chem.

Scand. 1993, 47, 728.(68) HAVFOZ. Stankovic, S.; Miljkovic, D.; Medic-Mijacevic, L.; Gasi,

K.; Courseille, C. Acta Crystallogr. 1994, C50, 1328.(69) HEKWUP. Low, J. N.; Ferguson, G.; Moreno-Carretero, M. N.;

Hueso-Urena, F. Acta Crystallogr. 1994, 50, 312.(70) HIBDEB. Russel, V. A.; Etter, M. C.; Ward, M. D. Chem. Mater.

1994, 6, 1206.(71) HIBDEB01. Videnova-Adrabinsk, V.; Turowska-Tyrk, I.; Borowiak,

T.; Dutkiewicz, G. New J. Chem. 2001, 25, 1403.(72) HIBGII-HIBGOO-HIBGUU. Ung, A. T.; Bishop, R.; Craig, D. C.;

Dance, I. G.; Scudder, M. L. Chem. Mater. 1994, 6, 1269.(73) HIDTET. Kuduva, S. S.; Blaser, D.; Boese, R.; Desiraju, G. R. J.

Org. Chem. 2001, 66, 1621.(74) HIKNOE. Zakharov, V. V.; Bugaeva, G. P.; Ivanova, M. E.;

Romanova, L. B.; Eremenko, L. T.; Nefedov, S. E.; Eremenko, I. L.IzV. Akad. Nauk SSSR, Ser. Khim. (Russ. Chem. Bull.) 1998, 1387.

(75) HIVBET. Mazurek, A. P.; Kozerski, L.; Sadlej, J.; Kawecki, R.;Bednarek, E.; Sitkowski, J.; Dobrowolski, J. C.; Maurin, J. K.;Biniecki, K.; Witowska, J.; Fiedor, P.; Pachecka, J. J. Chem. Soc.Perkin Trans. 2 1998, 1223.

(76) HNAFPY. Moreno, E.; Conde, A.; Marquez, R. Eur. Cryst. Meeting1979, 5, 398.

(77) HNAFPY10. Conde, A.; Moreno, E.; Marquez, R. Acta Crystallogr.1980, B36, 2730.

(78) HOTSOY. Orgueira, H.; Haj, M. A.; Salas, J. M.; Jensen, W. P.;Tiekink, E. R. T. Z.Kristallogr. New Cryst. Struct. 1999, 214, 517.

(79) HQUACN. Mak, T. C. W.; Lee, K.-S. Acta Crystallogr. 1978, B34,3631.

(80) HQUACN01. Chan, T.-L.; Mak, T. C. W. J. Chem. Soc. Perkin Trans.2 1983, 777.

(81) HUXMIW- HUXMUI. Boldog, I.; Rusanov, E. B.; Sieler, J.;Blaurock, S.; Domasevitch, K. V. Chem.Commun. 2003, 740.

(82) HYQHCL-HYQHCL01. Boeyens, J. C. A.; Pretorius, J. A. ActaCrystallogr. 1977, B33, 2120.

(83) HYQUIN. Maartman-Moe, K. Acta Crystallogr. 1966, 21, 979.(84) HYQUIN02. Wallwork, S. C.; Powell, H. M. K. J. Chem. Soc. Perkin

Trans. 2 1980, 641.(85) HYQUIN05. Lindeman, S. V.; Shklover, V. E.; Struchkov, Yu. Cryst.

Struct. Commun. 1981, 10, 1173.


(86) IBUXIN. Prakashareddy, J.; Pedireddi, V. R. Tetrahedron 2004, 60,8817.

(87) ICERAK. Chmielewski, M. J.; Szumna, A.; Jurczak, J. TetrahedronLett. 2004, 45, 8699.

(88) INUJUW - INUKAD - INUKAD01. Saied, O.; Maris, T.; Wuest,J. D. J. Am. Chem. Soc. 2003, 125, 14956.

(89) IQAFEL. Garnier, E.; Guillard, J.; Pasquinet, E.; Suzenet, F.; Poullain,D.; Jarry, C.; Leger, J.-M.; Lebret, B.; Guillaumet, G. Org. Lett. 2003,5, 4595.

(90) ITUXEA-ITUXIE. Kuleshova, L. N.; Antipin, M. Yu.; Khrustalev,V. N.; Gusev, D. V.; Grintselev-Knyazev, G.V.; Bobrikova, E. S.Cryst. Rep. 2003, 48, 594.

(91) JADMAD. Ermer, O.; Kusch, A.; Robke, C. HelV. Chim. Acta 2003,86, 922.

(92) JAKKEL. Mootz, D.; Brodalla, D.; Wiebcke, M. Acta Crystallogr.1989, C45, 754.

(93) JAMKEN. Birchall, T.; Frampton, C. S.; Schrobilgen, G. J.;Valsdottir, J. Acta Crystallogr. 1989, C45, 944.

(94) JARBOU. Franco, O.; Orgzall, I.; Reck, G.; Stockhause, S.; Schulz,B. J. Phys. Chem. Solids 2005, 66, 994.

(95) JIGCIL. Vicentini, C. B.; Veronese, A. C.; Poli, T.; Guarneri, M.;Giori, P.; Ferretti, V. J. Heterocycl. Chem. 1990, 27, 1481.

(96) JOZZED. Serra, M. A.; Dorner, B. K.; Silver, M. E. Acta Crystallogr.1992, C48, 1957.

(97) JUKVOA. Shin, W.; Cho, S. W.; Chae, C. H. Acta Crystallogr. 1993,C49, 294.

(98) JUNQIS. Kuduva, S. S.; Craig, D. C.; Nangia, A.; Desiraju, G. R.J. Am. Chem. Soc. 1999, 121, 1936.

(99) JUTGOU. Bertolasi, V.; Ferretti, V.; Gilli, P.; De Benedetti, P. G.J. Chem. Soc. Perkin Trans. 2 1993, 213.

(100) KAMBEG. Morita, Y.; Murata, T.; Fukui, K.; Yamada, S.; Sato,K.; Shiomi, D.; Takui, T.; Kitagawa, H.; Yamochi, H.; Saito, G.;Nakasuji, K. J. Org. Chem. 2005, 70, 2739.

(101) KANVUR. Dyachenko, V. D.; Rusanov, E. B. Khim. Get. Soedin.2004, 270.

(102) KAPFIR. Prakash, M. J.; Radhakrishnan, T. P. Cryst. Growth Des.2005, 5, 721.

(103) KAPVIH- KAPVIH01. Srinivasulu, A.; Nangia, A. Chem. Commun.2005, 3159.

(104) KERBAK. Ebisuno, T.; Takimoto, M.; Takahashi, M.; Shiba, R Bull.Chem. Soc. Jpn. 1988, 61, 4441.

(105) KUSTOH. Weber, A. E.; Steiner, M. G.; Krieter, P. A.; Colletti,A. E.; Tata, J. R.; Halgren, T. A.; Ball, R. G.; Doyle, J. J.; Schorn,T. W.; Stearns, R. A.; Miller, R. R.; Siegl, P. K. S.; Greenlee, W. J.;Patchett, A. A. J. Med. Chem. 1992, 35, 3755.

(106) LAYFUN. Tripathi, S. K.; Patel, U.; Roy, D.; Sunoj, R. B.; Singh,H. B.; Wolmershauser, G.; Butcher, R. J. J. Org. Chem. 2005, 70,9237.

(107) LEBLAG -LEBKUZ. Murata, T.; Morita, Y.; Nishimura, Y.;Nakasuji, K. Polyhedron 2005, 24, 2625.

(108) LORQOY- LORQUE. Bishop, R.; Craig, D. C.; Dance, I. G.;Scudder, M. L.; Ung, A. T. Zh. Strukt. Khim. 1999, 40, 822.

(109) LUVPUN. Korlyukov, A. A.; Chernyavskaya, N. A.; Antipin, M.Yu.; Chernyavskii, A. I. MendeleeV Commun. 2002, 236.

(110) LUYGAN. Friscic, T.; MacGillivray, L. R. J. Organomet. Chem.2003, 666, 43.

(111) MEQQUU. Macdonald, J. C.; Dorrestein, P. C.; Pilley, M. M. Cryst.Growth Des. 2001, 1, 29.

(112) MIGRID. Thallapally, P. K.; Katz, A. K.; Carrell, H. L.; Desiraju,G. R. Chem. Commun. 2002, 344.

(113) MIZRIW. Nomura, E.; Hosoda, A.; Taniguchi, H. J. Org. Chem.2001, 66, 8030.

(114) MURQOF. Ma, B. Q.; Coppens, P. Chem. Commun. 2003, 412.(115) NELRUR. Stomberg, R.; Langer, V.; Shiming, L.; Lundquist, K. Acta

Crystallogr., Sect. E: Struct. Report Online 2001, 57, o692.(116) NTRTAC. Stanford, H. Acta Crystallogr. 1967, 23, 825.(117) NTRTAC01. Skrzypczak-Jankun, E.; Smith, D. A.; Maluszynska,

H. Acta Crystallogr., Sect. C 1994, 50, 1097.(118) NUGNIM. Gleiter, R.; Fritzsche, G.; Borzyk, O.; Oeser, T.;

Rominger, F.; Irngartinger, H. J. Org. Chem. 1998, 63, 2878.(119) NUJQOY. Smith, B. D.; Hughes, M. P. J. Org. Chem. 1997, 62,

4492.(120) NUJQOY01. Zhuo, J.-C.; Soloway, A. H.; Beeson, J. C.; Ji, W.;

Barnum, B. A.; Rong, F.-G.; Tjarks, W.; Jordan IV, G. T.; Liu, J.;Shore, S. G. J. Org. Chem. 1999, 64, 9566.

(121) NUZKAU. Le Fury; Masse, R. Z.Kristallogr. New Cryst. Struct. 1998,213, 430.

(122) OHUJOQ. Nowicka-Scheibe, J.; Grech, E.; Sosnicki, J. G.; Glowiak,T.; Sawka-Dobrowolska, W.; Sobczyk, L. J. Mol. Struct. 2003, 655,17.

(123) PANGOB. Wei-Hua, Li.; Feng-Ling, Xu; Guan-Ping, Yu; Liang-Zhong, Xu Acta Crystallogr. 2005, E61, o2061.

(124) PAPSOO-PAPSUU. Ung, A. T.; Bishop, R.; Craig, D. C.; Scudder,M. L. Struct. Chem. 2001, 12, 251.

(125) PAZHOO. Tabuchi, Y.; Takahashi, A.; Gotoh, K.; Akashi, H.; Ishida,H. Acta Crystallogr. 2005, E61, o4215.

(126) PICTIE. Limori, T.; Murai, Y.; Wakizaka, Y.; Ohtsuka, Y.; Ohuchi,S.; Kodama, Y.; Oishi, T. Chem. Pharm. Bull. 1993, 41, 775.

(127) POKVUG -POLFIF. Craig, D. C.; Bishop, R.; Marougkas, A.;Scudder, M. L. Tetrahedron 1994, 50, 8749.

(128) QACPEP. Craciun, L.; Huang, R.; Mager, S. Monatsch Chem. 1998,129, 735.

(129) QECNAN. Jianping, Liu; Jordan, I. T.; Feng-Guang, Rong; Weihua,Ji; Zhuo, J.-C.; Soloway, A. H.; Beeson, J. C.; Barnum, B. A.; Tjarks,W.; Shore, S. G. J. Org. Chem. 1999, 64, 9566.

(130) QIFQIF. Bugella-Altamirano, E.; Gonzalez-Perez, J. M.; Sicilia-Zafra,A. G.; Niclos-Gutierrez, J.; Castineiras-Campos, A. Polyhedron 2000,19, 2463.

(131) QULKOX-QULLAK-QULKUD-QULLEO. Alshahateet, S. F.; Bishop,R.; Craig, D. C.; Scudder, M. L.; Ung, A. T. Struct. Chem. 2001,12, 251.

(132) QUOLSO. Palin, D. E.; Powell, H. M. J. Chem. Soc. 1947, 208.(133) QUOLSO01. Polyanskaya, T. M.; Alexeev, V. I.; Bakakin, V. V.;

Chekhova, G. N. Zh. Strukt. Khim. 1982, 23, 123.(134) QUSMEW. Vij, A.; Palmer, J. L.; Chauhan, K.; Williams, R. V.

J. Chem. Cryst. 2000, 30, 621.(135) RASBOD. Jayaraman, A.; Balasubramaniam, V.; Valiyaveettil, S.

Cryst. Growth Des. 2005, 5, 575.(136) SAYMUB-SAYMUB01. Zhenqiang, Wang; Shattock, T. R.; Vish-

weshwar, P.; Zaworotko, M. J. Cryst. Growth Des. 2005, 5, 2046.(137) SAYNAI-SAYNAI01. Kaftory, M.; Botoshansky, M.; Sheinin, Y.

Cryst. Growth Des. 2005, 5, 2242.(138) SEJSIJ. Emge, T. J.; Strickland, L. C.; Perkins, C. M. Acta

Crystallogr. 1990, C46, 286.(139) SIDVOQ. Man Shing, Wong; Liakatas, I.; Gramlich, V.; Bosshard,

C.; Gunter, P. AdV. Mater. 1998, 10, 777.(140) SIVTUM. Freeman, F.; Kim, D.S.H.L. J. Org. Chem. 1991, 56, 657.(141) SODVUC. Ung, A. T.; Bishop, R.; Craig, D. C.; Dance, I. G.;

Scudder, M. L. Chem. Commun. 1991, 1012.(142) TABJEL. Karlsson, O.; Lundquist, K.; Stomberg, R. Acta Chem.

Scand. 1990, 44, 617.(143) TADRUM. Liu, J.-G.; Xu, D.-J.; Sun, W.-L. Acta Crystallogr. 2003,

E59, O812.(144) (a) TAGUDN. Bracuti, A. J. Acta Crystallogr. 1979, B35, 760. (b)

TAGUDN01. Choi, C. S.; Prince, E. Acta Crystallogr. 1979, B35,761.

(145) TAKFER. Polishchuk, A. P.; Makarova, N. N.; Astapova, T. V.;Petrova, I. M. Kristallografiya 2002, 47, 856.

(146) TAKUHF. Polishchuk, A. P.; Makarova, N. N.; Astapova, T. V.Kristallografiya 2002, 47, 863.

(147) TAPIPZ. Lex, J.; Linke, K.-H. Chem. Ber. 1976, 109, 2684.(148) TAPZOA. Tafeenko, V. A.; Paseshnichenko, K. A.; Ershov, O. V.;

Eremkin, A. V.; Aslanov, L. A. Acta Crystallogr. 2005, C61, o434.(149) TAQXAL. Xiong, J.; Liu, M.-C.; Yuan, J.-X. Acta Crystallogr. 2005,

E61, o2665.(150) TERRUD. Dobson, A. J.; Gerkin, R. E. Acta Crystallogr. 1997, C53,

73.(151) TIJKOM. Cowan, J. A.; Howard, J. A. K.; Leech, M. A. Acta

Crystallogr. 2001, C57, 1196.(152) TIPKIM. Obrecht, D.; Lehmann, C.; Ruffieux, R.; Schonholzer, P.;

Muller, K. HelV. Chim. Acta 1995, 78, 1567.(153) TIPWIY. Videnova-Adrabinska, V. Acta Crystallogr. 1996, B52,

1048.(154) TIPWIY01. Smith, G.; Kennard, C. H. L.; Byriel, K. A. Aust. J. Chem.

1997, 50, 1021.(155) UDAYIH-UDAYUT-UDAYUT01. Boldog, I.; Rusanov, E. B.;

Chernega, A. N.; Sieler, J.; Domasevitch, K. V. Angew. Chem., Int.Ed. 2001, 40, 3435.

(156) UDAYUT02. Boldog, I.; Rusanov, E. B.; Sieler, J.; Blaurock, S.;Domasevitch, K. V. Chem. Commun. 2003, 741.

(157) UGUMUE. Twamley, B.; Gupta, O. D.; Shreeve, J. M. ActaCrystallogr. 2002, E58, O1040.

(158) UJOFEE-UJOFII. Fournier, J.-H.; Maris, T.; Simard, M.; Wuest, J. D.Cryst. Growth Des. 2003, 3, 535.

(159) ULAWEJ. Vishweshwar, P.; Nangia, A.; Lynch, V. M. Cryst. GrowthDes. 2003, 3, 783.


(160) VAKVIN. Vishweshwar, P.; Nangia, A.; Lynch, V. M. CrystEng-Comm 2003, 5, 164.

(161) VATPAI. Olmstead, M. M.; Sahbari, J. J. Acta Crystallogr. 2003,E59, o1648.

(162) VEJXAJ01 VEJXAJ. Wiedenfeld, V. H.; Knock, F. Acta Crystallogr.1990, C46, 1038.

(163) VOBFAT-VOBFEX-VOBFIB-VOBFOH-VOBFUN-VOBGAU. Erm-er, O.; Lindenberg, L. HelV. Chim. Acta 1991, 74, 825.

(164) VOJFAB-VOJFEF. Simard, M.; Su, D.; Wuest, J. D. J. Am. Chem.Soc. 1991, 113, 4696.

(165) VUSYIR. Ung, A. T.; Bishop, R.; Craig, D. C.; Dance, I. G.; Scudder,M. L. Tetrahedron 1993, 49, 639.

(166) WAKFOE. Alekseyev, R. S.; Karpova, E. V.; Zakharov, M. A.;Gutnikov, S. I. Acta Crystallogr. 2004, E60, o2491.

(167) WEQSUG. Kanoh, K.; Kohno, S.; Katada, J.; Takahashi, J.; Uno,I.; Hayashi, Y. Bioorg. Med. Chem. 1999, 7, 1451.

(168) WEZPEW. Jones, M. M.; Molenda, J. J.; Basinger, M. A. J. Med.Chem. 1994, 37, 93.

(169) WOVVUY. De Armas, H. N.; Peeters, O. M.; Blaton, N. M.; DeRanter, C. J.; Marill, L. X. Acta Crystallogr. 2001, C57, 86.

(170) WOYLEB. Kim, S.; Bishop, R.; Craig, D. C.; Dance, I. G.; Scudder,M. L. J. Org. Chem. 2002, 67, 3221.

(171) WUQYOW-WUQYUC. Sauriat-Dorizon, H.; Maris, T.; Wuest, J. D.;Enright, G. D. J. Org. Chem. 2003, 68, 240.

(172) XEBTIH. Reddy, D. S.; Dewa, T.; Endo, K.; Aoyama, Y. Angew.Chem., Int. Ed. 2000, 39, 4266.

(173) XISXAY. Carlucci, L.; Ciani, G.; Proserpio, D. M.; Rizzato, S. Chem.Eur. J. 2002, 8, 1520.

(174) XOMPOE. Prescott, H. A.; Troyanov, S.; Feist, M.; Kemnitz, E. Z.Anorg. Allg. Chem. 2002, 628, 1749.

(175) XUVBAR-XUVBIZ-XUVBEV. Wenzhuo, Guo; Fournier, J.-H.;Maris, T.; Wuest, J. D.; Galoppini, E. J. Am. Chem. Soc. 2003, 125,1002.

(176) YINJOU. Wang, X.; Simard, M.; Wuest, J. D. J. Am. Chem. Soc.1994, 116, 12119.

(177) YINJOU01. Saied, O.; Maris, T.; Wuest, J. D. J. Am. Chem. Soc.2003, 125, 14957.

(178) ZERMUE-ZERNEP. Toledo, L. M.; Musa, K.; Lauher, J. W.; Fowler,F. W. Chem. Mater. 1995, 7, 1639.

(179) ZUHHIT-ZUHHOZ- ZUHHUF- ZUHJAN. Feeder, N.; Jones, W.Acta Crystallogr. 1996, C52, 919.

(180) ZZZVLG01. Mak, T. C. W.; Tse, J. S.; Tse, C.-S.; Lee, K.-S.; Chong,Y.-H. J. Chem. Soc. Perkin Trans. 2 1976, 1169.

(181) ZZZVLI01. Mak, T. C. W. J. Chem. Soc. Perkin Trans. 2 1982,1435.

CG0705660


Documents

CRYSTAL GROWTH Interpenetrated Three-Dimensional Networks … · 2014-12-19 · Database. The great interest in the self-assembly of organic molecules into hydrogen-bonded supramolecular