metal-organic compounds
catena-Poly[[[diaquacobalt(II)]-bis{μ-2-[3-(4-carboxylatophenyl)pyridin-1-ium-1-yl]acetato}] dihydrate]
aCollege of Chemistry and Materials Science, Huaibei Normal University, 100 Dongshan Road, Huaibei, Anhui 235000, People's Republic of China
*Correspondence e-mail: zhangxiumeilb@126.com
In the title polymeric coordination compound, {[Co(C14H10NO4)2(H2O)2]·2H2O}n, the CoII ion resides on an inversion center and exhibits a distorted octahedral coordination geometry defined by four O atoms from two pairs of equivalent monodentate carboxylate groups from 2-[3-(4-carboxylatophenyl)pyridin-1-ium-1-yl]acetate ligands and by two O atoms from two equivalent coordinating water molecules. The zwitterionic dicarboxylate ligands serve as bridges with two monodentate carboxylate and the metal ions are linked by double bridges, forming polymeric chains running along [01-1]. The chains are further stabilized and associated into layers parallel to (011) through intra- and interchain hydrogen bonding and π–π stacking interactions [interplanar and centroid–centroid distances of 3.658 (3) Å and 3.653 (2) Å, respectively].
Related literature
For general background to zwitterionic ligands that contain more carboxylate groups than positive groups and hence have reduced negative charge, see: Zhang et al. (2010); Wang et al. (2009). For the synthesis of the ligand, see: Loeb et al. (2006).
Experimental
Crystal data
|
Data collection: SMART (Bruker, 2007); cell SAINT (Bruker, 2007); data reduction: SAINT; program(s) used to solve structure: SHELXTL (Sheldrick, 2008); program(s) used to refine structure: SHELXTL; molecular graphics: SHELXTL; software used to prepare material for publication: SHELXTL.
Supporting information
https://doi.org/10.1107/S1600536813008933/bg2502sup1.cif
contains datablocks I, global. DOI:Structure factors: contains datablock I. DOI: https://doi.org/10.1107/S1600536813008933/bg2502Isup2.hkl
The ligand was synthesized from 4-(3-pyridyl)benzoic acid and ethyl bromoacetate according to the procedure for similar compounds (Loeb et al., 2006). A mixture of the ligand (0.024 g, 0.10 mmol) and CoCl2.6H2O (0.010 g, 0.050 mmol) was thoroughly mixed in H2O (2 ml) and CH3OH (2 ml) in a Teflon-lined stainless steel vessel (25 ml), heated at 70°C for two days under autogenous pressure, and then cooled to room temperature. Red block crystals were harvested.
All the hydrogen atoms attached to carbon atoms were placed in calculated positions and refined using the riding model, and the water hydrogen atoms were located from the difference maps.
The zwitterionic ligands that contain more carboxylate groups than positive groups and hence have reduced negative charge have received little attention in crystal engineering and coordination chemistry (Zhang et al. (2010); Wang et al.. (2009)). The charge on the carboxylate ligand will certainly influence the coordination and supramolecular structures.
In this paper, we report the coordination and hydrogen-bond structure of the title CoII complex (I) derived from the zwitterionic ligand 3-carboxymethylpyridinium-4-benzoate (L).
The 1] (Fig.1). These coordination chains are further reinforced by the π-π interaction between the centrosymmetry-related phenylene groups (the interplanar and center-to-center distances are 3.658 (3) Å and 3.653 (2) Å respectively). Neighboring chains are associated via O—H···O hydrogen bonds mediated by lattice water molecules, which donate one hydrogen atom to a coordinated oxygen carboxylate from one chain and to a coordinated water molecule from another chain. Consequently, the chains are linked into layers (Fig. 2). The hydrogen bonding parameters are listed in Table 1.
of I contains a CoII ion on a centre of symmetry, one L ligand, one coordinated water molecule, and one lattice water molecule. Each Co atom resides in a distorted octahedral coordination geometry completed by four carboxylate O atoms from four L ligands and two O atoms from two coordinated water molecules. The Co—O distances lie in the range of 2.1031 (12)–2.1392 (14) Å. The L ligand binds two Co atoms through two monodentate carboxylate groups. Consequently, adjacent CoII centers are connected by a pair of zwitterionic ligands to give one-dimensional chains running along [01For general background to zwitterionic ligands that contain more carboxylate groups than positive groups and hence have reduced negative charge, see: Zhang et al. (2010); Wang et al. (2009). For the synthesis of the ligand, see: Loeb et al. (2006).
Data collection: SMART (Bruker, 2007); cell
SAINT (Bruker, 2007); data reduction: SAINT (Bruker, 2007); program(s) used to solve structure: SHELXTL (Sheldrick, 2008); program(s) used to refine structure: SHELXTL (Sheldrick, 2008); molecular graphics: SHELXTL (Sheldrick, 2008); software used to prepare material for publication: SHELXTL (Sheldrick, 2008).Fig. 1. The one-dimensional coordination chain with the π-π stacking and hydrogen bonds intrachain the chains. The intrachain hydrogen bonds and π-π stacking are shown as dot lines. [Symmetry codes: (i)-x + 1, -y + 1, -z + 1 (iii) -x + 1, -y, -z + 2 (iv)x, y + 1, z - 1] | |
Fig. 2. The two-dimensional layer assembled through hydrogen bonding interactions. [Symmetry codes: (i)-x + 1, -y + 1, -z + 1 (v)-x + 1, -y + 1, -z] |
[Co(C14H10NO4)2(H2O)2]·2H2O | V = 636.57 (4) Å3 |
Mr = 643.45 | Z = 1 |
Triclinic, P1 | F(000) = 333 |
Hall symbol: -P 1 | Dx = 1.679 Mg m−3 |
a = 7.5943 (3) Å | Mo Kα radiation, λ = 0.71073 Å |
b = 7.9123 (3) Å | µ = 0.75 mm−1 |
c = 10.7673 (4) Å | T = 296 K |
α = 88.769 (1)° | Block, red |
β = 81.681 (1)° | 0.10 × 0.08 × 0.06 mm |
γ = 83.920 (1)° |
Bruker SMART CCD area-detector diffractometer | 2477 independent reflections |
Radiation source: fine-focus sealed tube | 2449 reflections with I > 2σ(I) |
Graphite monochromator | Rint = 0.015 |
phi and ω scans | θmax = 26.0°, θmin = 1.9° |
Absorption correction: multi-scan (SADABS; Bruker, 2008) | h = −9→9 |
Tmin = 0.929, Tmax = 0.956 | k = −9→9 |
7933 measured reflections | l = −10→13 |
Refinement on F2 | Primary atom site location: structure-invariant direct methods |
Least-squares matrix: full | Secondary atom site location: difference Fourier map |
R[F2 > 2σ(F2)] = 0.030 | Hydrogen site location: inferred from neighbouring sites |
wR(F2) = 0.091 | H atoms treated by a mixture of independent and constrained refinement |
S = 1.05 | w = 1/[σ2(Fo2) + (0.0573P)2 + 0.4307P] where P = (Fo2 + 2Fc2)/3 |
2477 reflections | (Δ/σ)max < 0.001 |
208 parameters | Δρmax = 0.42 e Å−3 |
3 restraints | Δρmin = −0.43 e Å−3 |
[Co(C14H10NO4)2(H2O)2]·2H2O | γ = 83.920 (1)° |
Mr = 643.45 | V = 636.57 (4) Å3 |
Triclinic, P1 | Z = 1 |
a = 7.5943 (3) Å | Mo Kα radiation |
b = 7.9123 (3) Å | µ = 0.75 mm−1 |
c = 10.7673 (4) Å | T = 296 K |
α = 88.769 (1)° | 0.10 × 0.08 × 0.06 mm |
β = 81.681 (1)° |
Bruker SMART CCD area-detector diffractometer | 2477 independent reflections |
Absorption correction: multi-scan (SADABS; Bruker, 2008) | 2449 reflections with I > 2σ(I) |
Tmin = 0.929, Tmax = 0.956 | Rint = 0.015 |
7933 measured reflections |
R[F2 > 2σ(F2)] = 0.030 | 3 restraints |
wR(F2) = 0.091 | H atoms treated by a mixture of independent and constrained refinement |
S = 1.05 | Δρmax = 0.42 e Å−3 |
2477 reflections | Δρmin = −0.43 e Å−3 |
208 parameters |
Geometry. All e.s.d.'s (except the e.s.d. in the dihedral angle between two l.s. planes) are estimated using the full covariance matrix. The cell e.s.d.'s are taken into account individually in the estimation of e.s.d.'s in distances, angles and torsion angles; correlations between e.s.d.'s in cell parameters are only used when they are defined by crystal symmetry. An approximate (isotropic) treatment of cell e.s.d.'s is used for estimating e.s.d.'s involving l.s. planes. |
Refinement. Refinement of F2 against ALL reflections. The weighted R-factor wR and goodness of fit S are based on F2, conventional R-factors R are based on F, with F set to zero for negative F2. The threshold expression of F2 > σ(F2) is used only for calculating R-factors(gt) etc. and is not relevant to the choice of reflections for refinement. R-factors based on F2 are statistically about twice as large as those based on F, and R- factors based on ALL data will be even larger. |
x | y | z | Uiso*/Ueq | ||
Co1 | 0.5000 | 0.0000 | 1.0000 | 0.01887 (13) | |
C1 | 0.1280 (2) | 0.2122 (2) | 1.01741 (17) | 0.0240 (4) | |
C2 | −0.0189 (2) | 0.2764 (2) | 0.93891 (16) | 0.0236 (4) | |
H2A | −0.1265 | 0.2227 | 0.9683 | 0.028* | |
H2B | −0.0468 | 0.3982 | 0.9496 | 0.028* | |
C3 | 0.0277 (3) | 0.0817 (2) | 0.76392 (18) | 0.0262 (4) | |
H3A | −0.0235 | 0.0016 | 0.8182 | 0.031* | |
C4 | 0.0928 (3) | 0.0397 (2) | 0.64190 (19) | 0.0305 (4) | |
H4A | 0.0861 | −0.0691 | 0.6131 | 0.037* | |
C5 | 0.1687 (3) | 0.1600 (2) | 0.56150 (18) | 0.0280 (4) | |
H5A | 0.2178 | 0.1303 | 0.4797 | 0.034* | |
C6 | 0.1715 (2) | 0.3251 (2) | 0.60302 (17) | 0.0218 (4) | |
C7 | 0.1054 (2) | 0.3596 (2) | 0.72797 (17) | 0.0219 (4) | |
H7A | 0.1075 | 0.4681 | 0.7590 | 0.026* | |
C8 | 0.2383 (2) | 0.4612 (2) | 0.51779 (16) | 0.0217 (4) | |
C9 | 0.2396 (2) | 0.4480 (2) | 0.38854 (17) | 0.0243 (4) | |
H9A | 0.1995 | 0.3532 | 0.3564 | 0.029* | |
C10 | 0.3003 (2) | 0.5750 (2) | 0.30783 (17) | 0.0237 (4) | |
H10A | 0.3012 | 0.5640 | 0.2219 | 0.028* | |
C11 | 0.3597 (2) | 0.7182 (2) | 0.35321 (16) | 0.0221 (4) | |
C12 | 0.3616 (2) | 0.7305 (2) | 0.48192 (17) | 0.0235 (4) | |
H12A | 0.4038 | 0.8246 | 0.5135 | 0.028* | |
C13 | 0.3014 (2) | 0.6043 (2) | 0.56340 (16) | 0.0239 (4) | |
H13A | 0.3028 | 0.6148 | 0.6491 | 0.029* | |
C14 | 0.4175 (2) | 0.8612 (2) | 0.26645 (17) | 0.0225 (4) | |
O1 | 0.23496 (18) | 0.08802 (17) | 0.97274 (13) | 0.0280 (3) | |
O2 | 0.1218 (2) | 0.2815 (2) | 1.12000 (14) | 0.0381 (4) | |
O3 | 0.4574 (2) | 0.99102 (19) | 0.31444 (13) | 0.0371 (4) | |
O4 | 0.41823 (18) | 0.83772 (17) | 0.14971 (12) | 0.0268 (3) | |
O5 | 0.5063 (2) | −0.20597 (18) | 0.87341 (14) | 0.0309 (3) | |
H5C | 0.629 (4) | −0.250 (4) | 0.867 (3) | 0.046* | |
H5B | 0.504 (4) | −0.150 (4) | 0.806 (3) | 0.046* | |
O6 | 0.3383 (3) | 0.4835 (3) | −0.0904 (2) | 0.0637 (6) | |
H6A | 0.437 (4) | 0.402 (3) | −0.100 (4) | 0.096* | |
H6B | 0.399 (5) | 0.578 (3) | −0.108 (4) | 0.096* | |
N1 | 0.03825 (19) | 0.23849 (19) | 0.80482 (14) | 0.0213 (3) |
U11 | U22 | U33 | U12 | U13 | U23 | |
Co1 | 0.02626 (19) | 0.01584 (18) | 0.01403 (18) | −0.00255 (12) | −0.00149 (12) | 0.00310 (12) |
C1 | 0.0299 (9) | 0.0220 (9) | 0.0202 (9) | −0.0061 (7) | −0.0021 (7) | 0.0069 (7) |
C2 | 0.0257 (8) | 0.0247 (9) | 0.0185 (8) | −0.0008 (7) | 0.0008 (7) | 0.0034 (7) |
C3 | 0.0321 (9) | 0.0213 (9) | 0.0253 (9) | −0.0061 (7) | −0.0028 (7) | 0.0064 (7) |
C4 | 0.0403 (11) | 0.0208 (9) | 0.0299 (10) | −0.0037 (8) | −0.0029 (8) | 0.0005 (8) |
C5 | 0.0342 (10) | 0.0267 (9) | 0.0212 (9) | −0.0012 (8) | 0.0002 (7) | 0.0008 (7) |
C6 | 0.0225 (8) | 0.0227 (9) | 0.0196 (8) | −0.0007 (7) | −0.0023 (6) | 0.0046 (7) |
C7 | 0.0252 (8) | 0.0193 (8) | 0.0212 (9) | −0.0030 (7) | −0.0037 (7) | 0.0048 (7) |
C8 | 0.0217 (8) | 0.0227 (9) | 0.0189 (9) | 0.0004 (6) | −0.0003 (6) | 0.0056 (7) |
C9 | 0.0276 (9) | 0.0244 (9) | 0.0211 (9) | −0.0038 (7) | −0.0032 (7) | 0.0028 (7) |
C10 | 0.0255 (8) | 0.0283 (9) | 0.0164 (8) | −0.0003 (7) | −0.0022 (6) | 0.0049 (7) |
C11 | 0.0212 (8) | 0.0241 (9) | 0.0191 (9) | 0.0012 (7) | 0.0003 (6) | 0.0066 (7) |
C12 | 0.0277 (9) | 0.0220 (9) | 0.0202 (9) | −0.0018 (7) | −0.0021 (7) | 0.0025 (7) |
C13 | 0.0292 (9) | 0.0256 (9) | 0.0156 (8) | −0.0011 (7) | −0.0011 (7) | 0.0028 (7) |
C14 | 0.0250 (8) | 0.0226 (9) | 0.0183 (8) | 0.0007 (7) | −0.0003 (6) | 0.0043 (7) |
O1 | 0.0301 (7) | 0.0252 (7) | 0.0285 (7) | 0.0012 (5) | −0.0071 (5) | 0.0014 (5) |
O2 | 0.0499 (9) | 0.0381 (8) | 0.0265 (7) | 0.0040 (7) | −0.0121 (6) | −0.0041 (6) |
O3 | 0.0628 (10) | 0.0288 (7) | 0.0219 (7) | −0.0151 (7) | −0.0066 (7) | 0.0050 (6) |
O4 | 0.0387 (7) | 0.0241 (6) | 0.0173 (6) | −0.0066 (5) | −0.0011 (5) | 0.0055 (5) |
O5 | 0.0476 (9) | 0.0226 (7) | 0.0229 (7) | −0.0053 (6) | −0.0060 (6) | 0.0021 (5) |
O6 | 0.0462 (10) | 0.0515 (11) | 0.0891 (16) | −0.0104 (9) | 0.0100 (10) | −0.0085 (11) |
N1 | 0.0232 (7) | 0.0222 (7) | 0.0179 (7) | −0.0008 (6) | −0.0031 (6) | 0.0050 (6) |
Co1—O4i | 2.1031 (12) | C7—N1 | 1.346 (2) |
Co1—O4ii | 2.1031 (12) | C7—H7A | 0.9300 |
Co1—O1 | 2.1184 (13) | C8—C9 | 1.396 (3) |
Co1—O1iii | 2.1184 (13) | C8—C13 | 1.400 (3) |
Co1—O5iii | 2.1392 (14) | C9—C10 | 1.387 (3) |
Co1—O5 | 2.1392 (14) | C9—H9A | 0.9300 |
C1—O2 | 1.236 (2) | C10—C11 | 1.387 (3) |
C1—O1 | 1.263 (2) | C10—H10A | 0.9300 |
C1—C2 | 1.533 (3) | C11—C12 | 1.394 (2) |
C2—N1 | 1.474 (2) | C11—C14 | 1.512 (2) |
C2—H2A | 0.9700 | C12—C13 | 1.385 (3) |
C2—H2B | 0.9700 | C12—H12A | 0.9300 |
C3—N1 | 1.340 (2) | C13—H13A | 0.9300 |
C3—C4 | 1.370 (3) | C14—O3 | 1.244 (2) |
C3—H3A | 0.9300 | C14—O4 | 1.274 (2) |
C4—C5 | 1.387 (3) | O4—Co1iv | 2.1031 (12) |
C4—H4A | 0.9300 | O5—H5C | 0.95 (3) |
C5—C6 | 1.393 (3) | O5—H5B | 0.85 (3) |
C5—H5A | 0.9300 | O6—H6A | 0.927 (18) |
C6—C7 | 1.389 (3) | O6—H6B | 0.924 (18) |
C6—C8 | 1.483 (2) | ||
O4i—Co1—O4ii | 180.0 | C5—C6—C8 | 122.02 (17) |
O4i—Co1—O1 | 86.13 (5) | N1—C7—C6 | 120.95 (16) |
O4ii—Co1—O1 | 93.87 (5) | N1—C7—H7A | 119.5 |
O4i—Co1—O1iii | 93.87 (5) | C6—C7—H7A | 119.5 |
O4ii—Co1—O1iii | 86.13 (5) | C9—C8—C13 | 118.49 (16) |
O1—Co1—O1iii | 180.000 (1) | C9—C8—C6 | 119.86 (16) |
O4i—Co1—O5iii | 88.97 (5) | C13—C8—C6 | 121.65 (16) |
O4ii—Co1—O5iii | 91.03 (5) | C10—C9—C8 | 120.49 (17) |
O1—Co1—O5iii | 88.79 (6) | C10—C9—H9A | 119.8 |
O1iii—Co1—O5iii | 91.21 (6) | C8—C9—H9A | 119.8 |
O4i—Co1—O5 | 91.03 (5) | C11—C10—C9 | 121.02 (16) |
O4ii—Co1—O5 | 88.97 (5) | C11—C10—H10A | 119.5 |
O1—Co1—O5 | 91.21 (6) | C9—C10—H10A | 119.5 |
O1iii—Co1—O5 | 88.79 (6) | C10—C11—C12 | 118.66 (16) |
O5iii—Co1—O5 | 180.0 | C10—C11—C14 | 121.32 (16) |
O2—C1—O1 | 127.55 (18) | C12—C11—C14 | 120.01 (17) |
O2—C1—C2 | 116.33 (17) | C13—C12—C11 | 120.78 (17) |
O1—C1—C2 | 115.98 (16) | C13—C12—H12A | 119.6 |
N1—C2—C1 | 111.06 (14) | C11—C12—H12A | 119.6 |
N1—C2—H2A | 109.4 | C12—C13—C8 | 120.54 (16) |
C1—C2—H2A | 109.4 | C12—C13—H13A | 119.7 |
N1—C2—H2B | 109.4 | C8—C13—H13A | 119.7 |
C1—C2—H2B | 109.4 | O3—C14—O4 | 125.88 (17) |
H2A—C2—H2B | 108.0 | O3—C14—C11 | 117.89 (16) |
N1—C3—C4 | 119.77 (17) | O4—C14—C11 | 116.22 (16) |
N1—C3—H3A | 120.1 | C1—O1—Co1 | 132.41 (12) |
C4—C3—H3A | 120.1 | C14—O4—Co1iv | 127.67 (12) |
C3—C4—C5 | 119.77 (18) | Co1—O5—H5C | 100.6 (17) |
C3—C4—H4A | 120.1 | Co1—O5—H5B | 99.2 (19) |
C5—C4—H4A | 120.1 | H5C—O5—H5B | 102 (2) |
C4—C5—C6 | 120.13 (18) | H6A—O6—H6B | 98 (2) |
C4—C5—H5A | 119.9 | C3—N1—C7 | 121.83 (16) |
C6—C5—H5A | 119.9 | C3—N1—C2 | 118.73 (15) |
C7—C6—C5 | 117.43 (16) | C7—N1—C2 | 119.39 (15) |
C7—C6—C8 | 120.53 (16) |
Symmetry codes: (i) −x+1, −y+1, −z+1; (ii) x, y−1, z+1; (iii) −x+1, −y, −z+2; (iv) x, y+1, z−1. |
D—H···A | D—H | H···A | D···A | D—H···A |
O5—H5C···O2iii | 0.95 (3) | 1.91 (3) | 2.835 (2) | 164 (3) |
O5—H5B···O3i | 0.85 (3) | 1.80 (3) | 2.617 (2) | 162 (3) |
O6—H6A···O4v | 0.93 (2) | 2.13 (2) | 3.003 (2) | 156 (3) |
O6—H6B···O5iv | 0.92 (2) | 1.96 (2) | 2.880 (2) | 173 (4) |
Symmetry codes: (i) −x+1, −y+1, −z+1; (iii) −x+1, −y, −z+2; (iv) x, y+1, z−1; (v) −x+1, −y+1, −z. |
Experimental details
Crystal data | |
Chemical formula | [Co(C14H10NO4)2(H2O)2]·2H2O |
Mr | 643.45 |
Crystal system, space group | Triclinic, P1 |
Temperature (K) | 296 |
a, b, c (Å) | 7.5943 (3), 7.9123 (3), 10.7673 (4) |
α, β, γ (°) | 88.769 (1), 81.681 (1), 83.920 (1) |
V (Å3) | 636.57 (4) |
Z | 1 |
Radiation type | Mo Kα |
µ (mm−1) | 0.75 |
Crystal size (mm) | 0.10 × 0.08 × 0.06 |
Data collection | |
Diffractometer | Bruker SMART CCD area-detector |
Absorption correction | Multi-scan (SADABS; Bruker, 2008) |
Tmin, Tmax | 0.929, 0.956 |
No. of measured, independent and observed [I > 2σ(I)] reflections | 7933, 2477, 2449 |
Rint | 0.015 |
(sin θ/λ)max (Å−1) | 0.617 |
Refinement | |
R[F2 > 2σ(F2)], wR(F2), S | 0.030, 0.091, 1.05 |
No. of reflections | 2477 |
No. of parameters | 208 |
No. of restraints | 3 |
H-atom treatment | H atoms treated by a mixture of independent and constrained refinement |
Δρmax, Δρmin (e Å−3) | 0.42, −0.43 |
Computer programs: SMART (Bruker, 2007), SAINT (Bruker, 2007), SHELXTL (Sheldrick, 2008).
D—H···A | D—H | H···A | D···A | D—H···A |
O5—H5C···O2i | 0.95 (3) | 1.91 (3) | 2.835 (2) | 164 (3) |
O5—H5B···O3ii | 0.85 (3) | 1.80 (3) | 2.617 (2) | 162 (3) |
O6—H6A···O4iii | 0.927 (18) | 2.13 (2) | 3.003 (2) | 156 (3) |
O6—H6B···O5iv | 0.924 (18) | 1.961 (18) | 2.880 (2) | 173 (4) |
Symmetry codes: (i) −x+1, −y, −z+2; (ii) −x+1, −y+1, −z+1; (iii) −x+1, −y+1, −z; (iv) x, y+1, z−1. |
Acknowledgements
We are thankful for financial support from the NSFC (21201069) and the Natural Science Foundation of Anhui Province (1308085QB23).
References
Bruker (2007). SMART and SAINT. Bruker AXS Inc., Madison, Wisconsin, USA. Google Scholar
Bruker (2008). SADABS. Bruker AXS Inc., Madison, Wisconsin, USA. Google Scholar
Loeb, S. J., Tiburcio, J., Vella, S. J. & Wisner, J. A. (2006). Org. Biomol. Chem. 4, 667–671. Web of Science CSD CrossRef PubMed CAS Google Scholar
Sheldrick, G. M. (2008). Acta Cryst. A64, 112–122. Web of Science CrossRef CAS IUCr Journals Google Scholar
Wang, Y.-Q., Wang, K., Sun, Q., Tian, H., Gao, E.-Q. & Song, Y. (2009). Dalton Trans. pp. 9854–9859. Web of Science CSD CrossRef Google Scholar
Zhang, X.-M., Wang, Y.-Q. & Gao, E.-Q. (2010). Eur. J. Inorg. Chem. pp. 1249–1254. Web of Science CSD CrossRef Google Scholar
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The zwitterionic ligands that contain more carboxylate groups than positive groups and hence have reduced negative charge have received little attention in crystal engineering and coordination chemistry (Zhang et al. (2010); Wang et al.. (2009)). The charge on the carboxylate ligand will certainly influence the coordination and supramolecular structures.
In this paper, we report the coordination and hydrogen-bond structure of the title CoII complex (I) derived from the zwitterionic ligand 3-carboxymethylpyridinium-4-benzoate (L).
The asymmetric unit of I contains a CoII ion on a centre of symmetry, one L ligand, one coordinated water molecule, and one lattice water molecule. Each Co atom resides in a distorted octahedral coordination geometry completed by four carboxylate O atoms from four L ligands and two O atoms from two coordinated water molecules. The Co—O distances lie in the range of 2.1031 (12)–2.1392 (14) Å. The L ligand binds two Co atoms through two monodentate carboxylate groups. Consequently, adjacent CoII centers are connected by a pair of zwitterionic ligands to give one-dimensional chains running along [011] (Fig.1). These coordination chains are further reinforced by the π-π interaction between the centrosymmetry-related phenylene groups (the interplanar and center-to-center distances are 3.658 (3) Å and 3.653 (2) Å respectively). Neighboring chains are associated via O—H···O hydrogen bonds mediated by lattice water molecules, which donate one hydrogen atom to a coordinated oxygen carboxylate from one chain and to a coordinated water molecule from another chain. Consequently, the chains are linked into layers (Fig. 2). The hydrogen bonding parameters are listed in Table 1.