7/31/2019 ICC-2001-SBW

1/3

Unusual molecular ladder structure containing zinc(II) and naturalT-shape ligand nitrilotriacetate

Bai-Wang Sun, Zhe-Ming Wang, Song Gao *

State Key Laboratory of Rare Earth Materials Chemistry and Applications, Peking University The University of Hong Kong Joint Laboratory on Rare

Earth Materials and Bioinorganic Chemistry, Peking University, Beijing 100871, People's Republic of China

Received 21 August 2000; received in revised form 16 November 2000; accepted 17 November 2000

Abstract

A novel coordination polymer, Zn2bpyNTACl H2On (bpy 2,2H-bipyridine, H3 NTA nitrilotriacetic acid), has been

synthesized and its structure determined by X-ray diraction analysis, which consists of a ladder running along b axis where ZnII

ions are linked through the carboxylic groups acting as the rungs and rails of the ladder. 2001 Elsevier Science B.V. All rights

reserved.

Keywords: Ladder; Crystal structure; Zinc; Nitrilotriacetate (NTA)

Studies of the coordination chemistry of zinc(II) with

carboxylate ligands have aroused more and more in-

terest in the last decade in view of their biological

modeling applications [1,2] and solid-state materials

[3,4].

The nitrilotriacetate ion NCH2COO33 Y hereinaf-

ter referred to as NTA, is a remarkably versatile build-

ing block having seven potential donor atoms.

Crystallographic studies of various metal-NTA com-

plexes have previously been reported [512]. Our recent

work on complex Tm(III) has further highlighted its

versatility for coordination to more metal centers in a

variety of ways [13]. Three carboxylate groups in the

NTA ligand show a natural T-shape, which is essential

to give a ladder structure. Therefore, it is a good can-

didate for the assembly of molecular ladder. Manyladder-like coordination polymers with interesting net-

work topologies have been reported [1420], but only a

few of them have ligand NTA [13]. Here we report the

preparation and crystal structure of a novel molecular

ladder Zn2bpyNTACl H2On.Complex 1 was prepared by the reaction of ZnCl2 (1

mmol, 0.1363 g) with Na3 [NTA] (1 mmol, 0.2571 g) and

bpy (1 mmol 0.1562 g) in water solution. After the so-

lution had been stored at room temperature for two

weeks, colourless well-shaped crystals formed which

were ltered o, washed with water, and dried in vac-

uo. 1

The X-ray analysis 2 revealed that each zinc atom in

1 is in a highly distorted trigonal bipyramidal environ-

ment shown as in Fig. 1. The Zn(1) atom is coordinated

by one nitrogen atom of bpy ligand (Zn(1)N(1):

2.123(2) #A) and two O atoms from dierent carboxylate

groups of NTA ligand (Zn(1)O(1) 2.011(2), Zn(1)

Inorganic Chemistry Communications 4 (2001) 7981

www.elsevier.nl/locate/inoche

*Corresponding author. Fax: +86-1062751708.

E-mail address: gaosong@pku.edu.cn (S. Gao).

1 Satisfactory elemental data (C, H, N) were obtained. Anal.

Found: C, 36.54; H, 3.23; N, 8.02. Calc. For C16H16N3O7Zn2Cl1 X CY 36X36Y HY 3X05Y NY 7X95%X

2 The structure of compound 1 was studied at Nonius B. V. Demo

Lab in Peking University. Data were collected on a Nonius Kap-

paCCD diractometer with graphite monochromated MoKa radia-tion (k 0X71073 #A). Crystallographic data for 1: monoclinic, spacegroup P21an, a 9X49262Y b 8X86792Y c 22X91755 #A,b 99X641913, V 1901X937 #A3, Z 4Y Dc 1X846 Mg m

3.

Cell parameters were obtained by the global renement of the

positions of all collected reections. Integration was carried out by

the program DENZO-SMN, and data were corrected for Lorentz-

polarisation eects and for absorption using the program SCALE-

PACK. Solution was obtained by direct methods and followed by

subsequent Fourier-dierence syntheses (SHELXL 97). A total of

32981 was collected, of which 4538 (Rint 0X0697) was unique;equivalent reections were averaged. All non-hydrogen atoms were

rened anisotropic, while all hydrogenous were assigned to calculated

positions. The structure was rened by a full-matrix least-squares

technique to nd the results R1(0.0482) and wR2(0.0822), using the

weighting scheme.

1387-7003/01/$ - see front matter 2001 Elsevier Science B.V. All rights reserved.

PII: S 1 3 8 7 - 7 0 0 3 ( 0 0 ) 0 0 2 1 1 - 2

7/31/2019 ICC-2001-SBW

2/3

O(6B), 2.018(2), #A) in the equatorial plane, while the

other nitrogen atom of bpy ligand and O atom from

remainder carboxylate group of NTA ligand (Zn(1)

N(2), 2.139(2); Zn(1)O(4A) 2.085(2) #A) occupy the

axial positions with O(4A)Zn(1)N(2) at 164.90(7).

The coordination geometry of Zn(2) comprises three

carboxylate oxygen atoms and one nitrogen atom of

NTA ligand and one Cl atom. Three O atoms form the

equatorial plane (Zn(2)O(2), 2.011(2); Zn(2)O(5),

2.014(2); Zn(2)O(3), 2.032(2) #A). The axial positions

are occupied by Cl(1) and N(3), (Cl(1)Zn(2), 2.258(1);

Zn(2)N(3), 2.247(2) #A) with N(3)Zn(2)Cl(1) at177.65(5). ZnO and ZnN distances in 1 are in good

agreement with those in complex NaZn(NTA)H2O,which is a three-dimensional coordination polymer with

intricate network [21].

Fig. 2 shows the illustration for the assembly of an

innite ladder framework from T-shaped unit,

ZnNTACl2Y and node, Znbpy

2X The unit[Zn(bpy)(NTA)Cl] is used as a ladder motif corner. The

rails of the ladder are made of 8-atom units, Zn(1)

O(1)C(12)O(2)Zn(2)O(3)C(14)O(4) in which two

carboxylato groups of NTA bridge adjacent Zn(II)

atoms in antisyn mode. The rungs of the ladder are

made of another carboxylato group bridging two

Zn(II) atoms also in antisyn mode. The nearest

Zn Zn separation in the rail of the ladder is 4.941and 5.093 #A, respectively, and the nearest ZnZn dis-

tance in the rung is 5.166 #A. The distance between the

crystal water and its nearest atoms is larger than 3.2 #A,

so no hydrogen bonding was observed. The ladders arewell separated without hydrogen bonding and pp

stacking.

Acknowledgements

The nancial support from the National Natural

Science Foundation of China (No: 29771001 and

29831010) and the National Key Project Fundamental

Research (G1998061306), and the Excellent Young

Teachers Fund of MOE, P.R.C is gratefully acknowl-

edged.

Fig. 2. Scheme of the illustration for the assembly of an innite ladder

framework from T-shaped unit, ZnNTACl2

, and node,

Znbpy2.

Fig. 1. An ORTEP view of the crystal structure of complex1 showing

the 30% probability thermal motion ellipsoid. Selected bond distances

(#A) and angles (): Zn(1)O(1), 2.0105(17); Zn(1)O(4A), 2.0849(16);

Zn(1)O(6A), 2.0176(17); Zn(1)N(1), 2.123(2); Zn(1)N(2), 2.139(2);

Cl(1)Zn(2), 2.2580(7); Zn(2)O(2), 2.0105(17); Zn(2)O(5),

2.0143(18); Zn(2)O(3), 2.0324(18); Zn(2)N(3), 2.2471(19); O(1)

Zn(1)O(6B), 116.96(7); O(1)Zn(1)O(4A), 88.25(7); O(6B)Zn(1)

O(4A), 95.92(7); O(1)Zn(1)N(1), 104.79(7); O(6B)Zn(1)N(1),

137.77(7); O(4A)Zn(1)N(1), 91.23(7); O(1)Zn(1)N(2), 103.31(7);

O(6B)Zn(1)N(2), 87.54(7); O(4A)Zn(1)N(2), 164.90(7); N(1)

Zn(1)N(2), 76.57(8); O(2)Zn(2)O(5), 117.65(8); O(2)Zn(2)O(3),

110.25(8); O(5)Zn(2)O(3), 120.34(8); O(2)Zn(2)N(3), 78.99(7);

O(5)Zn(2)N(3), 79.00(7); O(3)Zn(2)N(3), 77.36(7); O(2)Zn(2)

Cl(1), 99.30(5); O(5)Zn(2)Cl(1), 103.27(5); O(3)Zn(2)Cl(1),

101.84(5); N(3)Zn(2)Cl(1), 177.65(5); O(2)C(12)O(1), 123.3(2);

O(4)C(14)O(3), 124.3(2); O(6)C(16)O(5), 124.9(2) Symmetry

transformations used to generate equivalent atoms: A: xY y 1Y z; B:x 3a2Y y 1a2Y z 1a2.

80 B.-W. Sun et al. / Inorganic Chemistry Communications 4 (2001) 7981

7/31/2019 ICC-2001-SBW

3/3

References

[1] X.M. Chen, Y.X. Tong, Inorg. Chem. 33 (1994) 4586.

[2] K.I. Nakamura, T. Koike, M. Shionoya, Y. Kodama, T. Ikeda,

M. Shiro, J. Am. Chem. Soc. 116 (1994) 4764.

[3] H. Kunkely, A. Volger, J. Chem. Soc., Chem. Commun. (1990)

1204.[4] C.F. Lee, K.F. Chin, S.M. Peng, C.M. Che, J. Chem. Soc., Dalton

Trans. (1993) 467.

[5] H.G. Visser, W. Purcell, S.S. Basson, Polyhedron 16 (1997) 2851.

[6] H.G. Visser, W. Purcell, S.S. Basson, Polyhedron 18 (1999) 2795.

[7] B.L. Barnett, V.A. Uchtman, Inorg. Chem. 18 (1979) 2674.

[8] L.P. Battaglia, A.B. Corradi, M.E.V. Tani, Acta Cryst. B 31

(1975) 1160.

[9] R.J. Butcher, B.R. Penfold, J. Crystal. Mol. Struct. 6 (1976) 13.

[10] V.V. Fomenko, L.I. Kopaneva, M.A. Porai-Koshits, T.N. Poly-

nova, Zh. Strukt. Khim. 15 (1975a) 645.

[11] V.V. Fomenko, L.I. Kopaneva, M.A. Porai-Koshits, T.N. Poly-

nova, Zh. Strukt. Khim. 15 (1975b) 651.

[12] J.F. Hoard, E.W. Silverton, J.V. Silverton, J. Am. Chem. Soc. 90

(1968) 2300.

[13] Y. Chen, B.Q. Ma, Q.D. Liu, J.R. Liu, S. Gao, Inorg. Chem.

Commun. 3 (2000) 319.

[14] A.J. Blake, N.R. Champness, S.S.M. Chung, W.S. Li, M.

Schroder, Chem. Commun. (1997) 1675.

[15] P. Losier, M.J. Zaworotko, Angew. Chem., Int, Ed. Engl. 35

(1996) 2779.

[16] A.R. Kennedy, R.E. Mulvey, A. Robertson, Chem. Commun.

(1998) 89.

[17] A.J. Blake, N.R. Champness, A. Khlobystov, D.A. Lemenovskii,

W.S. Li, M. Schroder, Chem. Commun. (1997) 2027.

[18] M. Ohba, N. Maruono, H. Okawa, T. Enoki, J.M. Latour, J. Am.

Chem. Soc. 116 (1994) 11566.

[19] S. Decurtins, M. Gross, H.W. Schmalle, S. Ferlay, Inorg. Chem.

37 (1998) 2443.

[20] B.W. Sun, S. Gao, Z.M. Wang, Chem. Lett. (2001) 2.

[21] J.D. Oliver, B.L. Barnett, L.C. Strickland, Acta Cryst. B 40 (1984)

377.

B.-W. Sun et al. / Inorganic Chemistry Communications 4 (2001) 7981 81