metal-organic compounds
Acta Crystallographica Section C
Crystal Structure
baran et al., 2009; Koshima et al., 2005; Childs & Hardcastle,
¨
2007; Aakeroy et al., 2007). Crystal engineering with coordi-
Communications
nation bonds is a very popular research area because of the
stable coordination bonds and versatile coordination modes of
metal ions, especially transition metals. However, transition
metal coordination compounds assembled by hydrogen-
bonding interactions have been less well studied (Liu et al.,
ISSN 0108-2701
Two two-dimensional hydrogen-
bonded coordination networks:
bis(3-carboxybenzoato-jO)bis(4-
methyl-1H-imidazole-jN3)copper(II)
and bis(3-methylbenzoato-jN)bis(4-
methyl-1H-imidazole-jN3)copper(II)
monohydrate
¨
¨
¨
2007; Beatty, 2001; Larsson & Ohrstrom, 2003; Aakeroy et al.,
1998, 2004). Therefore, our focus is on arranging transition
metal cationic centres through hydrogen bonds, attempting to
construct structures with interesting dimensions and topolo-
gies. We present here the two title two-dimensional hydrogen-
bonded coordination networks, viz. (I) and (II).
Ziliang Wanga* and Linheng Weib
aInstitute of Molecule and Crystal Engineering, College of Chemistry and Chemical
Engineering, Henan University, Kaifeng 475001, People’s Republic of China, and
bInstitute of Natural Resources and Environmental Science, College of Environment
and Planning, Henan University, Kaifeng 475001, People’s Republic of China
Correspondence e-mail: zlwang@henu.edu.cn
Received 8 August 2009
The molecular structure of (I) is shown in Fig. 1. The Cu2+
ion is coordinated by two 4-methyl-1H-imidazole (4-MeIM)
molecules and two 3-carboxybenzoate (HBDCꢁ) anions and is
located on an inversion centre, giving an approximate square-
Accepted 13 November 2009
Online 25 November 2009
The title two-dimensional hydrogen-bonded coordination
compounds, [Cu(C8H5O4)2(C4H6N2)2], (I), and [Cu(C8H7-
O2)2(C4H6N2)2]ꢀH2O, (II), have been synthesized and structu-
rally characterized. The molecule of complex (I) lies across an
inversion centre, and the Cu2+ ion is coordinated by two N
atoms from two 4-methyl-1H-imidazole (4-MeIM) molecules
and two O atoms from two 3-carboxybenzoate (HBDCꢁ)
anions in a square-planar geometry. Adjacent molecules are
linked through intermolecular N—Hꢀ ꢀ ꢀO and O—Hꢀ ꢀ ꢀO
hydrogen bonds into a two-dimensional sheet with (4,4)
topology. In the asymmetric part of the unit cell of (II) there
are two symmetry-independent molecules, in which each Cu2+
ion is also coordinated by two N atoms from two 4-MeIM
molecules and two O atoms from two 3-methylbenzoate
(3-MeBCꢁ) anions in a square-planar coordination. Two
neutral complex molecules are held together via N—Hꢀ ꢀ ꢀ
O(carboxylate) hydrogen bonds to generate a dimeric pair,
which is further linked via discrete water molecules into a two-
˚
planar arrangement [Cu1—O1 = 1.9442 (13ꢂ) A, Cu1—N1 =
˚
1.9763 (18) A and N1—Cu1—O1 = 89.95 (7) ]. Each 4-MeIM
molecule and HBDCꢁ anion binds to the metal centre through
one N atom and one O atom, respectively. Obviously, the
HBDCꢁ anion coordinates as a monodentate ligand to the
Cu2+ ion. The other carboxyl group does not lose its H atom,
so each [Cu(4-MeIM)2(HBDC)2] molecular unit simulta-
neously possesses two N—H donors and two O—H donors.
3
6 6 3
¨
dimensional network with the Schlafli symbol (4 )2(4 ,6 ,8 ).
In both compounds, as well as the strong intermolecular
hydrogen bonds, ꢀ–ꢀ interactions also stabilize the crystal
stacking.
Comment
Hydrogen bonds having good directionality and flexibility and
suitable strength are very important and have been widely
studied in physics, chemistry and biology (Beatty, 2003).
Moreover, most reported work on crystal engineering has
concentrated on organic supramolecular compounds (Ram-
Figure 1
The molecular structure of (I), showing the atom-numbering scheme.
Displacement ellipsoids are drawn at the 30% probability level and H
atoms are shown as small spheres of arbitrary radii. Unlabelled atoms are
related to labelled atoms by the symmetry transformation (ꢁx + 1, ꢁy + 2,
ꢁz + 1).
Acta Cryst. (2009). C65, m481–m484
doi:10.1107/S0108270109048203
# 2009 International Union of Crystallography m481