[Journal logo]

Volume 65 
Part 9 
Page m1091  
September 2009  

Received 30 June 2009
Accepted 12 August 2009
Online 19 August 2009

Key indicators
Single-crystal X-ray study
T = 294 K
Mean [sigma](C-C) = 0.003 Å
R = 0.036
wR = 0.097
Data-to-parameter ratio = 13.5
Details
Open access

Tetraaquabis(2-methylbenzimidazolium-1,3-diacetato-[kappa]O)zinc(II) tetrahydrate

aSchool of Chemistry and Chemical Engineering, Guangxi Normal University, Guilin 541004, People's Republic of China
Correspondence e-mail: lianhengchi@yahoo.com.cn

The asymmetric unit of the title compound, [Zn(C12H11N2O4)2(H2O)4]·4H2O, contains one-half of the complex molecule and two uncoordinated water molecules. The four water O atoms in the equatorial plane around the ZnII centre ([\overline 1] symmetry) form a distorted square-planar arrangement, while the distorted octahedral coordination geometry is completed by the O atoms of the zwitterionic 2-methylbenzimidazolium-1,3-diacetate ligands in the axial positions. The benzimidazole ring system is planar, with a maximum deviation of 0.041 (3) Å. Intramolecular O-H...O hydrogen bonding results in the formation of a non-planar six-membered ring. In the crystal structure, strong intra- and intermolecular O-H...O hydrogen bonds link the molecules into a three-dimensional network. [pi]-[pi] contacts between benzimidazole rings [centroid-centroid distance = 3.899 (1) Å] may further stabilize the structure.

Related literature

For general background to metal-organic frameworks, see: Robson et al. (2000[Robson, R. (2000). J. Chem. Soc. Dalton Trans. pp. 3735-3744.]); Kitagawa et al. (2004[Kitagawa, S., Kitaura, R. & Noro, S. (2004). Angew. Chem. Int. Ed. 43, 2334-2375.]). For a related structure, see: Ni et al. (2007[Ni, Q.-L., Li, F.-S., Jin, L.-L., He, P.-X. & Wang, X.-J. (2007). Chem. Res. Appl. (Chin. J.), 19, 1181-1184.]).

[Scheme 1]

Experimental

Crystal data
  • [Zn(C12H11N2O4)2(H2O)4]·4H2O

  • Mr = 703.95

  • Monoclinic, P 21 /n

  • a = 7.2749 (9) Å

  • b = 21.265 (3) Å

  • c = 9.7794 (12) Å

  • [beta] = 104.467 (2)°

  • V = 1464.9 (3) Å3

  • Z = 2

  • Mo K[alpha] radiation

  • [mu] = 0.92 mm-1

  • T = 294 K

  • 0.32 × 0.21 × 0.15 mm

Data collection
  • Bruker SMART CCD area-detector diffractometer

  • Absorption correction: multi-scan (SADABS; Sheldrick, 1996[Sheldrick, G. M. (1996). SADABS. University of Göttingen, Germany.]) Tmin = 0.757, Tmax = 0.874

  • 7436 measured reflections

  • 3202 independent reflections

  • 2582 reflections with I > 2[sigma](I)

  • Rint = 0.022

Refinement
  • R[F2 > 2[sigma](F2)] = 0.036

  • wR(F2) = 0.097

  • S = 1.10

  • 3202 reflections

  • 237 parameters

  • H atoms treated by a mixture of independent and constrained refinement

  • [Delta][rho]max = 0.98 e Å-3

  • [Delta][rho]min = -0.51 e Å-3

Table 1
Selected geometric parameters (Å, °)

Zn1-O5 2.1023 (17)
Zn1-O6 2.1128 (16)
Zn1-O4 2.1303 (14)

Table 2
Hydrogen-bond geometry (Å, °)

D-H...A D-H H...A D...A D-H...A
O5-H5B...O8 0.80 (4) 1.92 (4) 2.716 (3) 170 (3)
O6-H6A...O3 0.92 (4) 1.70 (4) 2.610 (2) 170 (3)
O6-H6B...O2ii 0.75 (3) 2.08 (3) 2.811 (2) 164 (3)
O7-H7A...O1iii 0.78 (4) 2.11 (4) 2.864 (3) 165 (4)
O7-H7B...O2iv 0.78 (4) 2.03 (4) 2.792 (2) 167 (3)
O8-H8A...O4iv 0.75 (3) 2.10 (3) 2.846 (2) 177 (3)
O8-H8B...O7v 0.79 (3) 2.00 (3) 2.786 (3) 168 (3)
Symmetry codes: (ii) [x-{\script{1\over 2}}, -y+{\script{1\over 2}}, z-{\script{1\over 2}}]; (iii) -x-1, -y+1, -z; (iv) x-1, y, z; (v) [x+{\script{1\over 2}}, -y+{\script{1\over 2}}, z+{\script{1\over 2}}].

Data collection: SMART (Bruker, 1998[Bruker (1998). SMART and SAINT. Bruker AXS Inc., Madison, Wisconsin, USA.]); cell refinement: SAINT (Bruker, 1998[Bruker (1998). SMART and SAINT. Bruker AXS Inc., Madison, Wisconsin, USA.]); data reduction: SAINT; program(s) used to solve structure: SHELXS97 (Sheldrick, 2008[Sheldrick, G. M. (2008). Acta Cryst. A64, 112-122.]); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008[Sheldrick, G. M. (2008). Acta Cryst. A64, 112-122.]); molecular graphics: SHELXTL (Sheldrick, 2008[Sheldrick, G. M. (2008). Acta Cryst. A64, 112-122.]); software used to prepare material for publication: SHELXTL.


Supplementary data and figures for this paper are available from the IUCr electronic archives (Reference: HK2732 ).


Acknowledgements

This work was supported by the Natural Science Foundation of Guangxi Province (grant No. 0832100) and the Programme for Excellent Talents in Guangxi Higher Education Institutions.

References

Bruker (1998). SMART and SAINT. Bruker AXS Inc., Madison, Wisconsin, USA.
Kitagawa, S., Kitaura, R. & Noro, S. (2004). Angew. Chem. Int. Ed. 43, 2334-2375.  [ISI] [CrossRef] [ChemPort]
Ni, Q.-L., Li, F.-S., Jin, L.-L., He, P.-X. & Wang, X.-J. (2007). Chem. Res. Appl. (Chin. J.), 19, 1181-1184.  [ChemPort]
Robson, R. (2000). J. Chem. Soc. Dalton Trans. pp. 3735-3744.  [CrossRef]
Sheldrick, G. M. (1996). SADABS. University of Göttingen, Germany.
Sheldrick, G. M. (2008). Acta Cryst. A64, 112-122.  [CrossRef] [details]


Acta Cryst (2009). E65, m1091  [ doi:10.1107/S1600536809031766 ]

This is an open-access article distributed under the terms of the Creative Commons Attribution Licence, which permits unrestricted use, distribution, and reproduction in any medium, provided the original authors and source are cited.