4..N OTIC FILE COPYUAITY CLASSiIFI(ATION 01$ 11011 FA~

~E~O~DCUMENTATIONPAGEi 1b, RESTRICTIVE MARKINGS

AE L,0, _NoneA,,.,3 4 - ISTRISUTINIAVAJL&SILITY OF REPORTAD-A223 409 Approved for public release.CHEOUL Distribution unlimited.

4. PERFORMING ORGANIZATION REPORT NUMBE 5. MONITORING ORGANIZATION REPORT NUMBER(S)

TECHNICAL REPORT 110

6. NAME OF PERFORMING ORGANIZATION 6b. OFFICE SYMBOL 7a. NAME OF MONITORING ORGANIZATION

University of Massachusetts Of JPPlkable) Office of Naval Research

6C_ ADDRESS (Gty, State. and ZIP Code) 7b. ADORESS (City, State. ard ZiP Code)

Department of Chemistry 800 N. Quincy Street

Lederle raduate Research.Tower Arlington VA 22217-5000

8.. NAME OF FUNOING/SPONSORING 8b. OFFKE SYMBOL 9. PROCUREMENT INSTRUMENT IDENTIFICATION NUMBERORGANIZATION (If applka8bl)

Office of Naval Research ONR

Sc. ADORESS (O,, State. and ZIP Code) 10. SOURCE OF FUNDING NUMBERS

800 N. Quincy Street PROGRAM PROJECT TASK WORK UNITELEMENT NO. NO. NO. ACCESSION NO

Arlington VA 22217-5000 N00014-87 K-0464

11. TIE (Onude SeCwty o.,i6caion) (UNCLASSIFIED)

THEORETICAL INVESTIGATIONS AND ATTEMPTED SYNTHESIS OF ORGANIC MAGNETIC POLYMERS

12. PERSONAL AUTHOR(S)P.M. Lahti

13a, 'TYPE OF REPORT 13b. IME COVERED J14. ATE OF REPORT (Year. Month. Day) S. PAGE COUNTAnnual Report I FROM 11-1-88 roiO-1-891 6 Mar 1990

16. SUPPEMENTARY NOTATION

Presented at Fall, 1989 OUR Contractor's Meeting : Summary of slide presentation.

17. CosAn CODES is.uejcr TERMS (Cnd,,e on mryw Ar-neceiay and iden tiy by block number)REL0 GROUP SUB-GROUP Organic radicals; organic polyradicals; theoretical and

computational chemistry; unimolecular radical synthesis ,

19. ABSTRACT f(C-thn rfevvr if necenarv And ident6f by bxk numbeid

Progresn ir theoretical and synthetic investigations of organic magnetic species is outlined by slides

presented at the Office of Naval Research contractors' meeting of Fall, 1989. Overall, progress was made in

synthesis of appropriate groups to allow photochemical and thermal generation of phenoxyl radicals in the

solid phase. Thermal stability of a variety of substituted phenoxyl systems generated by these methods in

PPMA matrices was investigated.

90 06 29 033MO. OSTRISUTIONIAVAILAUIUTY OF ABSTRACT 21. ABSTRACT SECURITY CLASSIFICATION

IUNCLASSIFIEOAJNUMITEO 03 SAME AS APT. 0 OTIC USERS Non-classified

22s. NAME OF RESPONSIBLE INDIVIDUAL n ll- E - .,Dr. Kenneth Wynne / Dr. JoAnn Mliiken z Are zoe 2 1 ~IESMO

OFFICE OF NAVAL RESEARCH

Contract # N00014-87-K-0464

R&T Code 413c037

Technical Report # 10

THEORETICAL INVESTIGATIONS AND ATTEMPTED SYNTHESIS OF ORGANICMAGNETIC POLYMERS AND OLIGOMERS

by Paul M. Lahti

Accesion For

NTIS CRA&IPresented at DTIC TAB

Unannounced

Office of Naval Research Contractors' Meeting JuslrficatioiAutumn, 1989

ByDistribution I

University of Massachusetts Ava3iLbility CodesDepartment of Chemistry Aail nd or

Amherst, MA 01003 Dis pcial

Submitted 6 March 1990

Reproduction in whole or In part Is permitted for

any purpose of the United States Government

This document has been approved for public release and sale; its distribution is unlimited.

THEORETICAL INVESTIGATIONSAND ATTEMPTED SYNTHESIS

OF ORGANIC MAGNETIC POLYMERSAND OLIGOMERS

by Paul M. LahtiDepartment of Chemistry

University of MassachusettsAmherst, MA 01003

OBJECTIVE:

To investigate the possibilies of generating magnetic information storagematerials from-basically non-metallic organic precursors, in order tocombine the technological usefulness of magnetism with the practicalusefulness of organic polymeric materials.

APPROACH

Theoretical computations allow selection of polyradicalpolymerstructures likely to yield high-spin magnetic properties.Experimentall we synthesize as model'compounds small segments ofa potential highly magnetic polymer, then test the predictions of theoryby standard methods- or inVestigati.g maonetic properties (electronspin resonance, magnetic susceptibility). SuccessfuI predictions forsmall models will ifmply that it is worth attempting synthesis of largerpolymers predicted to have desirable magnetic properties.

RESULT:

Theory does predict that linkage of several radical units into an oligomerwill in many cases yield high-spin organic polyradicals. Experimentalgeneration of such species will constitute the first step toward creatingtruly polymeric magnetically imaged organic materials.

IDELIZED USE OF PLYRAOCL MAGNTIC WITERD4L

Inert Polymer Backbone(Support Phase).

* -4 .Latent Magnetic Precursor'lp O Overlaid onInertlye Base.

Information EncodedBy "Developing" Some

P ortion of PrecursorTo Become Magnetic.

INTEREST IN ORGANIC FERROMAGNETIC MATERIALS

J. S. Miller, A. J. Epstein, W. M. Reiff Chem. Rev. 88, 201 (1988),Accts. Chem. Res., 21, 114(1988).

R. Breslow, et al. Pure App!. Chem., 54, 927(1982),J. Am. Chem. Sac., 109, 6412(1987),J. Am. Chem. Soc., 110, 3970(1988)

Yu. V. Korshak, T. V. Medvedeva, A. A. Ovchinnikov, V. N. Spector

Nature, 126, 370(1987)

J. B. Torrance, S. Qostra, A. Nazzal Synth. Metals, 19, 709(1987).

Experimental Work Toward Synthesis of High Spin Polyradicals

Examples include:

Cf. T. Sugawara, S. Bandow, K. Kimura, HR Iwamura, K. Itoh, J. Am. Chem. Soc.1984, 106, 6449; 1986,108, 368 and references therein.

N2

Hhv H

n3-5 cryogenic matrix

high spin statepolycarbenes

observed, characterized

H. Nishide, N. Yoshioka, K. Inagaki, E. Tsuchida, Macromolecules, 1988, 21, 3120.

OH O"tBu BU t Bu tBu

[0]

MW= 1-3x0 O

Stable, with about1 free spin / 10 monomers

by ESR spin.counting.

Y. Miura, T. Ohana, J. Org. Chem., 1988,53, 5770.

S-'a S PbO2 S.SHN NH "N N -

tBU ~ benzene

tBu tBu t Bu tBu J oligomers

DESIRED: A unimolecular strategy to generate phenoxyl radicalsin solution OR in solid state.

STRATEGY

ArG-X-Lv , " I A . xLv.

diamagnetic paramagneticlabile precursor phenoxyl radical

OUR PRESENT METHOD

0 0 Xenon arcIIli.

ArO-C-C-O-O- Bu ArO CO2 CO tBuO °

or

heat >700C

ADVANTAGES

1. Easy and cheap to make2. Fairly easy to store for some time, soluble in common solvents3. Some photolability, easy thermal decomposition at > 700C.

POSSIBLE FUTURE APPROACHES

00II II

ArO-C-C-X X = N=NR, I, CPh 3

Synthesis of Peroxvoxalate Precursorsfor Phcrioxy Systems

CMe 3 CMe 3

OH CI-COCO-CI C ' -CO-CO-Cl

R CMe3 R CMe 3

R CH3 . C(CH 3 ,H , CAH 'B uOOH,pyridine, CC14

QOC

CO CO2CMe 3 -O'Bu CMe 3

5, 0-A o, O-CO-C02-OtBu

R AZ- C Me 3 hvRj (CMe 3

stable for several days pentane recryst. at -78*C

at 25'C in benzene good room temperature stability

ESR 'HNMR, IR

0-co-co-c'

Yk hvh (

Y RT, benzene eOMeOe

3496 gauss

I 7.1 gauss

ESR Spectra in rigid matrix are much broader than in solution

Frozen Benzene Matrix

Benzene solution (fluid)

30 gauss

O-C0CO00tBu 00'Bu z tBu hv IBU r tBu

'Bu 'Bu

K: CI-c hv 077K, benzene

3412 gauss

81lgauss

- -coco-cl 11v0

PPMA matrix solution77 K

(SIMILAR LOSS OF FINE STRUCTURE IS OBSERVED IN NEAT SAM1PLE IRRADIATION)

EPA glass

O- - - - -~fll

00precursor

Sphotolysis 33 as77 K

0 MTHF glass

151 gauss

Synt'hcsis of Dioxy-StilbenesI

0 OMe

CH 11H0 2C -~-.C 2-C-OH ~CHO

MeO MeO MeO

mieta or para meta or para meta, meta'meta, para'

/Cu chroinifte Cu chromitequin oline cholidine

H~O-MeH H ~

MeO eOMeO

O-COCO-X OHH ~/H

1. 2 BuLi

X-OC-2. CI-cO3t Bu HO

(X = .OOtBu)

I 1. 2BuUhv~ or A 2. xs CIOCOCIO

1 00 O-cOcO-xH -/hv H /

.0 X-COCO-O

meta , mecta'meta, para' (X = C1)

O-C-C-O-OtBu

II II

O00

O-C-C-O-O-tBu

00precursor

I photolysis77 K

if only one centerTheory predicts generated. get aa paramagnetic 1 monoradicaltriplet ground statefor this molecule. gp0a -

diradical is producedwhen both centers

are generated

3430 gauss (half-field observed, 25 gauss wide)

204 gauss

,, .OBSERVED SPECTRUM OF IRRADIATED DIRADICAL PRECURSOR IN MATRIX (77K)

SU. OF META and PARA-OXYSTILBENE ESR SPECTRA(SIMULATED)

33 gauiss

t3430 gauss

STABILITY OF UNHINDERED PHENOXYs IS EASILY MONITOREDIN POLYMERIC MATRIX BY UV-vis SPECTROSCOPY.

AOB hv 0

PPMA 77K

AO3 -O-COCO-OOtBu

( r c t

'-00 0

(Arrows indicate the para-stilbenoxy absorbances)

IUNHINDERED RADICAL STABILITY IN MATRIX

Unhindered para-stilbenoxy appears indefinitely stable by UV-vis when generatedin PPMA at 13K. When warmed swiftly (<4 min) to 90K, rapid absorbance decayoccurs, which slows and leaves the absorbance (radical concentration) approachingan asymptotic value. Warming again to 170K results in the same behavior, withthe final result being a much decreased (relative to the 13K value) but still finiteamount of radical with stability for at least 5h at 170K At room temperature, theradical appears to be completely quenched. Similar behavior occurs in poly-styrene, but onset of decay behavior is faster. Some decay in both matrices hasalready occured by 77K with our typical 10% wt/wt radical-in-polymer mixes.

With some optimization, further increase in stabilization of unhindered radicalsin polymer matrix may be possible.

DECAY OF p-STILBENOXY IN PPMA

0.8

Original value of optical0.7 density at 13K (stable). Optical Density

Temperature ramped to Temperature ramped to 170 K90K on a photolyzed f. from 90K. after optical density

0.6-/ value stabilized at this value

0.5-0- 0

0.4

0 0.3 Final value of persistentradical optical density at1_70K (at least 5h stability)

0.2-

0.1 . . . . . | . . . . . J . . . . . . .

0 100 200 300 400 500 600 700

Time/mn

A NEW, EFFICIENT SYNTHESIS OF para-OLEFINIC2,6-di-tert-Butylphenolic polymer precursors.

O OH

tBU tBu 2 eq. LiCH 2 PPh 3Br tBu ' tBU

H CH 2

(previously reported in D. Braun,B. Meier, Makronol Chem, 167, 119(1973))

AIBNH-(CO)-N(TMS) 2 toluene

MeCN. 900 C 65-750 C

OTMS OHtBu tBU 1. BF3 /Et 2 O 'Bu tBu

2. Bu 4 NF

n

further functlonalizationof this polymer to the

polyradical is desirable.

[FUTURE WORK I1. Nitrenes and polynitrenes N-

N.. -..

N- N- -

N.

2. Poly(2,6-di-tert-butyl-4-oxy-styrene) derivatives and copolymers.Polymers with pendant hindered stilbenoxy groups.

hv hv

"0 K~tBu- AB IB" tBU A BU a B

OH 0. AOB+ highly paramagnetic?

tBuOO(CO)(CO)OOtBu

II I

x x x

' BU 'BtU

NAOB . otBU tBU

highly paramagnetic?

3. Optimize radical production in polymer matrices

PPMA // ArO-X-Lv , , PPMA //ArO X Lv

ACKNOWLED GEMENTS

Group Members

David Modarelli Organic Magnetic MaterialsFrank Rossitto Organic Magnetic MaterialsMasaki Minato Organic Magnetic MaterialsAndrew Ichimura Computational (Folyradicals)Frank R. Denton 1M1 Conducting PolymersAnanda Sarker Conducting PolymersMark Kearley Pentamethylenepropanes

Support

Office of Naval Research (Magnetic Materials)National Science Foundation (Departmental Computing)

Air Force Office of Scientific Research (Conducting Polymrers)Petroleum Research Fund (Pentamethylenepropanes)

Research Corporation (UV Spectroscopy)Exxon Education FoundationUniversity of Massachusetts