Poly[[octaaqua-μ4-(benzene-1,2,4,5-tetra-carboxyl-ato)-dicobalt(II)] octa-hydrate].

The title polymeric coordination compound, {[Co2(C10H2O8)(H2O)8]·8H2O} n , was obtained by slow diffusion of a dilute aqueous solution of CoCl2 and the sodium salt of benzene-1,2,4,5-tetracarboxylic acid (H4btec) through an agar-agar gel bridge in a U-shaped tube. The two independent Co(2+) ions are each situated on an inversion centre and are coordinated in a slightly distorted octa-hedral geometry by four water O atoms and two carboxyl-ate O atoms from two btec(4-) ligands (-1> symmetry), forming a layer parallel to (11-1). This layer can be described as a mol-ecular two-dimensional square grid with the benzene rings at the nodes and the Co(II) atoms connecting the nodes. O-H⋯O hydrogen-bonding interactions involving the coordinating water molecules, the carboxylate O atoms and lattice water molecules lead to the formation of a three-dimensional network.

Related literature

For related metal-organic materials with large channels and cavities, see: Yaghi et al. (1998 ▶); Evans et al. (1999 ▶); Eddaoudi et al. (2002 ▶); Guillou et al. (2006 ▶). For examples of coordination polymers containing the btec4− ligand, see: Cheng et al. (2000 ▶); Rochon & Massarweh (2000 ▶); Chu et al. (2001 ▶); Wu et al. (2002 ▶); Luo et al. (2013 ▶). For related crystal-growth methods in gels, see: Henisch & Rustum (1970 ▶); Henisch (1988 ▶); Daiguebonne et al. (2003 ▶).

Experimental

Crystal data

[Co2(C10H2O8)(H2O)8]·8H2O

M = 656.22

Triclinic,

a = 5.4371 (1) Å

b = 9.8496 (3) Å

c = 10.2564 (3) Å

α = 96.445 (1)°

β = 91.232 (1)°

γ = 91.328 (1)°

V = 545.48 (3) Å3

Z = 1

Mo Kα radiation

μ = 1.64 mm−1

T = 298 K

0.10 × 0.09 × 0.06 mm

Data collection

Bruker APEXII diffractometer

8487 measured reflections

2456 independent reflections

2092 reflections with I > 2σ(I)

R int = 0.025

Refinement

R[F 2 > 2σ(F 2)] = 0.048

wR(F 2) = 0.153

S = 0.97

2456 reflections

166 parameters

H-atom parameters constrained

Δρmax = 0.60 e Å−3

Δρmin = −0.81 e Å−3

Data collection: APEX2 (Bruker, 2007 ▶); cell refinement: SAINT (Bruker, 2007 ▶); data reduction: SAINT; program(s) used to solve structure: SHELXS97 (Sheldrick, 2008 ▶); program(s) used to refine structure: SHELXL2013 (Sheldrick, 2008 ▶); molecular graphics: DIAMOND (Brandenburg, 1999 ▶); software used to prepare material for publication: publCIF (Westrip, 2010 ▶).

Crystal structure: contains datablock(s) I. DOI: 10.1107/S1600536813031577/vn2077sup1.cif

Structure factors: contains datablock(s) I. DOI: 10.1107/S1600536813031577/vn2077Isup2.hkl

Additional supplementary materials: crystallographic information; 3D view; checkCIF report

[Co2(C10H2O8)(H2O)8]·8H2O	V = 545.48 (3) Å3
Mr = 656.22	Z = 1
Triclinic, P1	F(000) = 340
a = 5.4371 (1) Å	Dx = 1.998 Mg m−3
b = 9.8496 (3) Å	Mo Kα radiation, λ = 0.71073 Å
c = 10.2564 (3) Å	µ = 1.64 mm−1
α = 96.445 (1)°	T = 298 K
β = 91.232 (1)°	Prism, very light pink
γ = 91.328 (1)°	0.10 × 0.09 × 0.06 mm

Bruker APEXII diffractometer	2092 reflections with I > 2σ(I)
Radiation source: Fine-focus sealed tube	Rint = 0.025
Graphite monochromator	θmax = 27.5°, θmin = 2.0°
CCD rotation images, thin slices scans	h = −6→7
8487 measured reflections	k = −12→12
2456 independent reflections	l = −13→13

Refinement on F2	0 restraints
Least-squares matrix: full	Hydrogen site location: difference Fourier map
R[F2 > 2σ(F2)] = 0.048	H-atom parameters constrained
wR(F2) = 0.153	w = 1/[σ2(Fo2) + (0.0911P)2 + 2.3818P] where P = (Fo2 + 2Fc2)/3
S = 0.97	(Δ/σ)max < 0.001
2456 reflections	Δρmax = 0.60 e Å−3
166 parameters	Δρmin = −0.81 e Å−3

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.

	x	y	z	Uiso*/Ueq
H1	0.0869	0.1434	0.3071	0.050*
H13	0.0780	−0.2852	−0.0807	0.050*
H4	0.2169	−0.2460	0.0208	0.050*
H5	0.4549	0.1226	0.5668	0.050*
H6	−0.4194	−0.4465	0.1454	0.050*
H7	0.2609	0.1784	0.6194	0.050*
H9	−0.1925	−0.3972	0.2127	0.050*
H10	0.1381	0.0269	0.2641	0.050*
Co1	0.0000	0.0000	0.5000	0.0165 (2)
Co2	0.0000	−0.5000	0.0000	0.0180 (2)
O22	−0.0419 (5)	−0.3362 (3)	0.3694 (3)	0.0246 (6)
O12	0.2439 (5)	−0.5016 (3)	0.1641 (3)	0.0212 (6)
O23	0.2189 (5)	−0.1729 (3)	0.4617 (3)	0.0224 (6)
O11	0.0733 (6)	−0.6758 (3)	0.2541 (3)	0.0352 (8)
O1	0.3013 (5)	0.1098 (3)	0.5906 (3)	0.0308 (7)
O2	−0.2644 (6)	−0.4222 (4)	0.1330 (3)	0.0399 (8)
C1	0.3561 (6)	−0.5310 (4)	0.3841 (3)	0.0159 (7)
O3	0.0735 (7)	0.0657 (3)	0.3177 (3)	0.0381 (8)
C3	0.5172 (7)	−0.6259 (4)	0.4275 (3)	0.0170 (7)
H3	0.5283	−0.7109	0.3786	0.020*
C2	0.3387 (6)	−0.4025 (3)	0.4587 (3)	0.0150 (7)
C22	0.1578 (6)	−0.2968 (4)	0.4251 (3)	0.0158 (7)
C11	0.2111 (7)	−0.5719 (4)	0.2586 (3)	0.0180 (7)
O4	0.1143 (9)	−0.3016 (4)	−0.0152 (4)	0.0596 (13)
O14	0.2936 (16)	−0.0732 (8)	0.1144 (8)	0.121 (3)
O16	0.5551 (16)	−0.1850 (8)	0.0171 (9)	0.121 (3)
O15	−0.4581 (14)	0.0456 (9)	0.1989 (8)	0.116 (2)
O17	0.8066 (16)	−0.0714 (9)	0.1011 (8)	0.124 (3)

	U11	U22	U33	U12	U13	U23
Co1	0.0162 (4)	0.0120 (3)	0.0218 (4)	0.0031 (2)	−0.0002 (3)	0.0034 (3)
Co2	0.0196 (4)	0.0198 (4)	0.0146 (3)	−0.0009 (3)	−0.0048 (2)	0.0036 (3)
O22	0.0202 (13)	0.0222 (13)	0.0296 (14)	0.0064 (10)	−0.0078 (11)	−0.0047 (11)
O12	0.0217 (13)	0.0263 (14)	0.0160 (12)	−0.0007 (11)	−0.0063 (10)	0.0054 (10)
O23	0.0186 (13)	0.0124 (12)	0.0362 (15)	0.0043 (10)	−0.0029 (11)	0.0023 (11)
O11	0.051 (2)	0.0243 (15)	0.0307 (16)	−0.0129 (14)	−0.0227 (14)	0.0108 (12)
O1	0.0192 (14)	0.0204 (14)	0.0511 (19)	0.0020 (11)	−0.0027 (12)	−0.0030 (13)
O2	0.0224 (15)	0.073 (3)	0.0221 (15)	0.0016 (15)	−0.0025 (11)	−0.0034 (15)
C1	0.0176 (16)	0.0160 (16)	0.0140 (15)	0.0013 (13)	−0.0038 (12)	0.0022 (13)
O3	0.064 (2)	0.0211 (15)	0.0307 (16)	0.0035 (14)	0.0150 (15)	0.0072 (12)
C3	0.0207 (17)	0.0121 (15)	0.0175 (16)	0.0027 (13)	−0.0029 (13)	−0.0011 (12)
C2	0.0161 (16)	0.0131 (15)	0.0161 (16)	0.0032 (12)	−0.0009 (12)	0.0027 (12)
C22	0.0155 (16)	0.0162 (16)	0.0157 (16)	0.0032 (13)	0.0000 (12)	0.0014 (13)
C11	0.0217 (17)	0.0147 (16)	0.0173 (17)	0.0063 (13)	−0.0062 (13)	0.0003 (13)
O4	0.099 (3)	0.045 (2)	0.0354 (19)	−0.040 (2)	−0.038 (2)	0.0205 (16)
O14	0.141 (7)	0.106 (6)	0.112 (6)	−0.001 (5)	0.012 (5)	−0.009 (4)
O16	0.127 (6)	0.106 (5)	0.131 (6)	−0.003 (5)	−0.023 (5)	0.025 (5)
O15	0.105 (5)	0.146 (7)	0.101 (5)	0.022 (5)	−0.002 (4)	0.022 (5)
O17	0.142 (7)	0.127 (6)	0.101 (5)	0.020 (5)	−0.017 (5)	0.004 (5)

Co1—O1	2.084 (3)	Co2—O12	2.122 (2)
Co1—O1i	2.084 (3)	O22—C22	1.249 (4)
Co1—O3	2.089 (3)	O12—C11	1.266 (5)
Co1—O3i	2.089 (3)	O23—C22	1.270 (4)
Co1—O23	2.106 (2)	O11—C11	1.250 (5)
Co1—O23i	2.106 (2)	C1—C3	1.398 (5)
Co2—O2	2.101 (3)	C1—C2	1.410 (5)
Co2—O4	2.060 (3)	C1—C11	1.505 (5)
Co2—O4ii	2.061 (3)	C3—C2iii	1.390 (5)
Co2—O2ii	2.101 (3)	C2—C3iii	1.390 (5)
Co2—O12ii	2.122 (2)	C2—C22	1.511 (5)
O1—Co1—O1i	180.0	O2ii—Co2—O12ii	87.12 (11)
O1—Co1—O3	92.62 (14)	O2—Co2—O12ii	92.88 (11)
O1i—Co1—O3	87.38 (14)	O4—Co2—O12	88.91 (12)
O1—Co1—O3i	87.38 (14)	O4ii—Co2—O12	91.09 (12)
O1i—Co1—O3i	92.62 (14)	O2ii—Co2—O12	92.88 (11)
O3—Co1—O3i	180.0	O2—Co2—O12	87.12 (11)
O1—Co1—O23	90.10 (11)	O12ii—Co2—O12	180.0
O1i—Co1—O23	89.90 (11)	C11—O12—Co2	124.9 (2)
O3—Co1—O23	92.24 (12)	C22—O23—Co1	130.4 (2)
O3i—Co1—O23	87.76 (12)	C3—C1—C2	118.8 (3)
O1—Co1—O23i	89.90 (11)	C3—C1—C11	117.7 (3)
O1i—Co1—O23i	90.10 (11)	C2—C1—C11	123.5 (3)
O3—Co1—O23i	87.76 (12)	C2iii—C3—C1	122.2 (3)
O3i—Co1—O23i	92.24 (12)	C3iii—C2—C1	119.0 (3)
O23—Co1—O23i	180.0	C3iii—C2—C22	118.1 (3)
O4—Co2—O4ii	180.0	C1—C2—C22	122.8 (3)
O4—Co2—O2ii	91.81 (19)	O22—C22—O23	124.9 (3)
O4ii—Co2—O2ii	88.19 (19)	O22—C22—C2	118.8 (3)
O4—Co2—O2	88.19 (19)	O23—C22—C2	116.2 (3)
O4ii—Co2—O2	91.81 (19)	O11—C11—O12	124.9 (3)
O2ii—Co2—O2	180.0	O11—C11—C1	117.4 (3)
O4—Co2—O12ii	91.09 (12)	O12—C11—C1	117.7 (3)
O4ii—Co2—O12ii	88.91 (12)

D—H···A	D—H	H···A	D···A	D—H···A
O3—H1···O11iv	0.79	1.92	2.698 (4)	169
O4—H4···O14	0.82	1.89	2.636 (9)	150
O4—H4···O16	0.82	1.92	2.632 (10)	143
O1—H5···O23v	0.89	1.87	2.746 (4)	171
O2—H6···O12vi	0.89	1.92	2.803 (4)	177
O1—H7···O22i	0.75	1.97	2.664 (4)	154
O2—H9···O22	0.90	1.82	2.725 (4)	176
O3—H10···O14	0.73	1.95	2.682 (9)	176
O3—H10···O15vii	0.73	2.32	2.848 (9)	130
O4—H13···O11ii	0.73	1.94	2.618 (5)	154

Table 1

Selected bond lengths (Å)

Co1—O1	2.084 (3)
Co1—O3	2.089 (3)
Co1—O23	2.106 (2)
Co2—O2	2.101 (3)
Co2—O4	2.060 (3)
Co2—O12	2.122 (2)

Table 2

Hydrogen-bond geometry (Å, °)

D—H⋯A	D—H	H⋯A	D⋯A	D—H⋯A
O3—H1⋯O11i	0.79	1.92	2.698 (4)	169
O4—H4⋯O14	0.82	1.89	2.636 (9)	150
O4—H4⋯O16	0.82	1.92	2.632 (10)	143
O1—H5⋯O23ii	0.89	1.87	2.746 (4)	171
O2—H6⋯O12iii	0.89	1.92	2.803 (4)	177
O1—H7⋯O22iv	0.75	1.97	2.664 (4)	154
O2—H9⋯O22	0.90	1.82	2.725 (4)	176
O3—H10⋯O14	0.73	1.95	2.682 (9)	176
O3—H10⋯O15v	0.73	2.32	2.848 (9)	130
O4—H13⋯O11vi	0.73	1.94	2.618 (5)	154

Symmetry codes: (i) ; (ii) ; (iii) ; (iv) ; (v) ; (vi) .