Poly[[diaqua­(μ₈-benzene-1,2,4,5-tetra­carboxyl­ato)calciumzinc] monohydrate]

In the title complex, {[CaZn(C₁₀H₂O₈)(H₂O)₂]·H₂O}_n, the Zn^II ion is coordinated by four O atoms from four benzene-1,2,4,5-tetra­carboxyl­ate anions in a distorted tetra­hedral geometry. The Ca^II ion is eight-coordinated by six O atoms from four benzene-1,2,4,5-tetra­carboxyl­ate anions and by two water mol­ecules in a distorted square-anti­prismatic geometry. The Ca^II and Zn^II ions and the lattice water mol­ecule are located on twofold rotation axes; the centroid of the benzene-1,2,4,5-tetra­carboxyl­ate anion is located on a centre of inversion. The μ₈-bridging mode of the anion results in the formation of a three-dimensional structure with channels extending along [100] in which lattice water mol­ecules are situated. Inter­molecular O—H...O hydrogen bonds involving the coordinating and lattice water mol­ecules as donors and the carboxyl­ate O atoms and lattice water mol­ecules as acceptors are present in the structure.

Key indicators

• Single-crystal X-ray study
• T = 293 K
• Mean [sigma](C-C) = 0.003 Å
• R factor = 0.027
• wR factor = 0.099
• Data-to-parameter ratio = 13.7

checkCIF/PLATON results

No syntax errors found



Alert level C
PLAT790_ALERT_4_C Centre of Gravity not Within Unit Cell: Resd.  #          1
              C10 H6 Ca O10 Zn
PLAT911_ALERT_3_C Missing # FCF Refl Between THmin & STh/L=  0.600         13
PLAT976_ALERT_2_C Negative Residual Density at 0.51A from O6     .      -0.48 eA-3

Alert level G
PLAT004_ALERT_5_G Info: Polymeric Structure Found with Dimension .          3
PLAT005_ALERT_5_G No _iucr_refine_instructions_details in CIF ....          ?
PLAT007_ALERT_5_G Note: Number of Unrefined D-H Atoms ............          3
PLAT199_ALERT_1_G Check the Reported _cell_measurement_temperature        293 K
PLAT200_ALERT_1_G Check the Reported   _diffrn_ambient_temperature        293 K
PLAT764_ALERT_4_G Overcomplete CIF Bond List Detected (Rep/Expd) .       1.32 Ratio
PLAT790_ALERT_4_G Centre of Gravity not Within Unit Cell: Resd.  #          2
              H2 O
PLAT912_ALERT_4_G Missing # of FCF Reflections Above STh/L=  0.600         17

   0 ALERT level A = Most likely a serious problem - resolve or explain
   0 ALERT level B = A potentially serious problem, consider carefully
   3 ALERT level C = Check. Ensure it is not caused by an omission or oversight
   8 ALERT level G = General information/check it is not something unexpected

   2 ALERT type 1 CIF construction/syntax error, inconsistent or missing data
   1 ALERT type 2 Indicator that the structure model may be wrong or deficient
   1 ALERT type 3 Indicator that the structure quality may be low
   4 ALERT type 4 Improvement, methodology, query or suggestion
   3 ALERT type 5 Informative message, check

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S1. Comment

A large number of complexes constructed from the multidentate aromatic ligand benzene-1,2,4,5-tetracarboxylic acid and its corresponding anions have been extensively studied due to the diversity of the coordination modes and sensitivity to pH values of the carboxylate anions. Some of the final products exhibit useful functional properties (Prajapati et al., 2009; Xie et al., 2008). In order to further explore complexes with new structures, we selected benzene-1,2,4,5-tetracarboxylic acid as precursor to self-assembly with ZnCl₂ and CaCl₂ simultaneously in solution and obtained the title complex, [CaZn(C₁₀H₂O₈)(H₂O)₂]^.(H₂O), the crystal structure of which is reported herein.

As shown in Figure 1, the Zn^II ion displays a distorted tetrahedral coordination geometry defined by four oxygen atoms from four symmetry-related benzene-1,2,4,5-tetracarboxylate groups (O1, O1A, O4B and O4C). The Ca^II ion is bound to six oxygen atoms from four benzene-1,2,4,5-tetracarboxylate groups (O1E, O1D, O2, O2F, O3D, O3E) and two water molecules (O5, O5F) leading to a distorted square-antiprismatic geometry. The base plane of the square antiprism consists of atoms O1E, O2F, O3E, and O5F with a mean deviation of 0.1065 Å from the least-squares plane. The top plane of the square antiprism consists of symmetry-related atoms O1D, O2, O3D, and O5. The dihedral angle between the two planes is 3.9 °. The three-dimensional set-up of the structure leaves space for channels extending along [100] where the lattice water molecules are located.

Intermolecular O—H···O hydrogen bonds between coordinating water molecules and lattice water molecules, between coordinating water molecules and carboxylate groups, and between solvent water molecules and carboxylate groups consolidate the crystal packing (Table 1, Fig. 2).

Related literature

For background to complexes based on benzene-1,2,4,5-tetracarboxylic acid and its anions, see: Prajapati et al. (2009); Xie et al. (2008).

S2. Experimental

A mixture of ZnCl₂ (0.05 mmol), CaCl₂ (0.05 mmol), benzene-1,2,4,5-tetracarboxylic acid (0.05 mmol), water (4 ml) and methanol (4 ml) was placed in a 25 ml Teflon-lined stainless steel vessel and heated at 393 K for 72 h, then cooled to room temperature. Colourless crystals were obtained from the filtrate and dried in air.

S3. Refinement

The H atom bound to C5 was positioned geometrically and refined as riding, with C—H = 0.93 Å. H atoms bound to water O atoms were found from difference maps and refined with distance restraints of O—H = 0.85 Å. All H atoms were refined with U_iso(H) = 1.2 U_eq(C,O).

Computing details

Data collection: CrystalClear (Rigaku/MSC, 2004); cell refinement: CrystalClear (Rigaku/MSC, 2004); data reduction: CrystalClear (Rigaku/MSC, 2004); program(s) used to solve structure: SHELXS97 (Sheldrick, 2008); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008); molecular graphics: SHELXTL (Sheldrick, 2008); software used to prepare material for publication: publCIF (Westrip, 2010).

Figures

	Fig. 1. View of the building units of the title compound showing the coordination environment around the metal ions. The displacement parameters of the atoms are displayed at the 30% probability level. [Symmetry code A: -x, y, -z - 1/2; B: x - 1, y, z; C: -x + 1, y, -z - 1/2; D: -x + 1, -y, -z - 1; E: x, -y - 1, z + 1/2; F: -x + 1, y, 1/2 - z; G: -x + 1, -y, -z.].
	Fig. 2. Packing plot of the title complex with O—H···O hydrogen bonds indicated by dashed lines.

Poly[[diaqua(µ₈-benzene-1,2,4,5-tetracarboxylato)calciumzinc] monohydrate]

Crystal data

[CaZn(C10H2O8)(H2O)2]·H2O	F(000) = 412
Mr = 409.61	Dx = 2.207 Mg m^−3
Monoclinic, P2/c	Mo Kα radiation, λ = 0.71073 Å
a = 6.2006 (12) Å	Cell parameters from 1852 reflections
b = 9.770 (2) Å	θ = 2.1–27.9°
c = 11.259 (3) Å	µ = 2.47 mm^−1
β = 115.33 (2)°	T = 293 K
V = 616.5 (2) Å^3	Prism, colourless
Z = 2	0.19 × 0.17 × 0.14 mm

Data collection

Rigaku Saturn CCD diffractometer	1447 independent reflections
Radiation source: fine-focus sealed tube	1360 reflections with I > 2σ(I)
Graphite monochromator	Rint = 0.027
Detector resolution: 28.5714 pixels mm^-1	θmax = 27.9°, θmin = 2.1°
ω scans	h = −8→7
Absorption correction: multi-scan (CrystalClear; Rigaku/MSC, 2004)	k = −12→12
Tmin = 0.651, Tmax = 0.723	l = −14→9
3849 measured reflections

Refinement

Refinement on F^2	Primary atom site location: structure-invariant direct methods
Least-squares matrix: full	Secondary atom site location: difference Fourier map
R[F^2 > 2σ(F^2)] = 0.027	Hydrogen site location: inferred from neighbouring sites
wR(F^2) = 0.099	H-atom parameters constrained
S = 0.84	w = 1/[σ^2(Fo^2) + (0.1P)^2] where P = (Fo^2 + 2Fc^2)/3
1447 reflections	(Δ/σ)max < 0.001
106 parameters	Δρmax = 0.38 e Å^−3
0 restraints	Δρmin = −0.56 e Å^−3

Special details

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.

Fractional atomic coordinates and isotropic or equivalent isotropic displacement parameters (Ų)

	x	y	z	Uiso*/Ueq
Zn1	0.0000	−0.23661 (3)	−0.2500	0.01455 (15)
Ca1	0.5000	−0.51637 (6)	0.2500	0.01865 (18)
O1	0.2538 (3)	−0.34567 (15)	−0.11362 (14)	0.0200 (3)
O2	0.5157 (3)	−0.35902 (17)	0.09520 (15)	0.0244 (4)
O3	0.7153 (3)	−0.29814 (17)	−0.11799 (15)	0.0221 (3)
O4	0.8547 (3)	−0.10913 (16)	−0.16958 (16)	0.0209 (3)
O5	0.0955 (3)	−0.4370 (2)	0.14219 (19)	0.0345 (4)
H5A	0.0534	−0.3562	0.1510	0.041*
H5B	−0.0270	−0.4882	0.1110	0.041*
C1	0.4111 (4)	−0.2941 (2)	−0.00731 (19)	0.0144 (4)
C2	0.7341 (3)	−0.1716 (2)	−0.11904 (19)	0.0156 (4)
C3	0.4642 (3)	−0.1423 (2)	−0.00489 (18)	0.0138 (4)
C4	0.6098 (3)	−0.0840 (2)	−0.05841 (18)	0.0139 (4)
C5	0.3573 (4)	−0.0571 (2)	0.05340 (18)	0.0160 (4)
H5	0.2618	−0.0953	0.0898	0.019*
O6	1.0000	0.1852 (4)	−0.2500	0.0787 (13)
H6	0.9216	0.1282	−0.2269	0.094*

Atomic displacement parameters (Ų)

	U^11	U^22	U^33	U^12	U^13	U^23
Zn1	0.0131 (2)	0.0155 (2)	0.0160 (2)	0.000	0.00726 (16)	0.000
Ca1	0.0200 (3)	0.0125 (3)	0.0166 (3)	0.000	0.0012 (2)	0.000
O1	0.0177 (7)	0.0131 (7)	0.0220 (7)	−0.0011 (5)	0.0016 (6)	0.0009 (5)
O2	0.0274 (8)	0.0226 (8)	0.0185 (7)	0.0040 (6)	0.0054 (6)	0.0062 (6)
O3	0.0241 (8)	0.0164 (7)	0.0272 (8)	−0.0003 (7)	0.0123 (7)	−0.0057 (6)
O4	0.0220 (8)	0.0206 (7)	0.0271 (8)	−0.0008 (6)	0.0171 (7)	−0.0036 (6)
O5	0.0247 (8)	0.0326 (9)	0.0434 (11)	0.0056 (8)	0.0118 (8)	0.0062 (8)
C1	0.0128 (9)	0.0134 (9)	0.0171 (9)	0.0011 (7)	0.0063 (7)	−0.0012 (7)
C2	0.0110 (8)	0.0198 (10)	0.0144 (9)	0.0009 (8)	0.0040 (7)	−0.0045 (7)
C3	0.0118 (8)	0.0148 (9)	0.0136 (9)	−0.0016 (7)	0.0043 (7)	−0.0032 (7)
C4	0.0121 (8)	0.0153 (10)	0.0136 (9)	−0.0013 (7)	0.0050 (7)	−0.0031 (7)
C5	0.0156 (9)	0.0174 (10)	0.0160 (9)	−0.0031 (8)	0.0077 (7)	−0.0023 (7)
O6	0.071 (3)	0.040 (2)	0.085 (3)	0.000	−0.005 (2)	0.000

Geometric parameters (Å, º)

Zn1—O4^i	1.9701 (15)	O3—C2	1.243 (3)
Zn1—O4^ii	1.9701 (15)	O3—Ca1^v	2.3618 (17)
Zn1—O1^iii	1.9754 (15)	O4—C2	1.273 (3)
Zn1—O1	1.9754 (15)	O4—Zn1^vii	1.9701 (15)
Ca1—O2^iv	2.3571 (17)	O5—H5A	0.8500
Ca1—O2	2.3571 (17)	O5—H5B	0.8500
Ca1—O3^v	2.3618 (17)	C1—C3	1.517 (3)
Ca1—O3^vi	2.3618 (17)	C2—C4	1.497 (3)
Ca1—O5^iv	2.4003 (19)	C3—C5	1.391 (3)
Ca1—O5	2.4003 (19)	C3—C4	1.403 (3)
Ca1—O1^v	2.9172 (16)	C4—C5^viii	1.392 (3)
Ca1—O1^vi	2.9172 (16)	C5—C4^viii	1.392 (3)
O1—C1	1.280 (2)	C5—H5	0.9300
O1—Ca1^v	2.9172 (16)	O6—H6	0.8500
O2—C1	1.231 (3)
O4^i—Zn1—O4^ii	101.57 (9)	O3^v—Ca1—O1^vi	72.21 (5)
O4^i—Zn1—O1^iii	109.22 (7)	O3^vi—Ca1—O1^vi	66.20 (5)
O4^ii—Zn1—O1^iii	110.65 (7)	O5^iv—Ca1—O1^vi	123.51 (6)
O4^i—Zn1—O1	110.65 (7)	O5—Ca1—O1^vi	75.32 (6)
O4^ii—Zn1—O1	109.22 (7)	O1^v—Ca1—O1^vi	124.96 (6)
O1^iii—Zn1—O1	114.72 (9)	C1—O1—Zn1	123.33 (14)
O2^iv—Ca1—O2	98.59 (9)	C1—O1—Ca1^v	108.26 (12)
O2^iv—Ca1—O3^v	140.78 (6)	Zn1—O1—Ca1^v	105.21 (6)
O2—Ca1—O3^v	103.07 (6)	C1—O2—Ca1	149.04 (15)
O2^iv—Ca1—O3^vi	103.07 (6)	C2—O3—Ca1^v	141.97 (13)
O2—Ca1—O3^vi	140.78 (6)	C2—O4—Zn1^vii	111.98 (13)
O3^v—Ca1—O3^vi	79.77 (9)	Ca1—O5—H5A	123.2
O2^iv—Ca1—O5^iv	77.30 (6)	Ca1—O5—H5B	125.0
O2—Ca1—O5^iv	78.37 (7)	H5A—O5—H5B	109.3
O3^v—Ca1—O5^iv	138.88 (7)	O2—C1—O1	124.0 (2)
O3^vi—Ca1—O5^iv	75.09 (7)	O2—C1—C3	117.63 (18)
O2^iv—Ca1—O5	78.37 (7)	O1—C1—C3	118.31 (17)
O2—Ca1—O5	77.30 (6)	O3—C2—O4	123.82 (17)
O3^v—Ca1—O5	75.09 (7)	O3—C2—C4	119.71 (17)
O3^vi—Ca1—O5	138.88 (7)	O4—C2—C4	116.47 (18)
O5^iv—Ca1—O5	142.29 (10)	C5—C3—C4	118.95 (18)
O2^iv—Ca1—O1^v	152.50 (5)	C5—C3—C1	116.74 (18)
O2—Ca1—O1^v	73.48 (5)	C4—C3—C1	124.31 (17)
O3^v—Ca1—O1^v	66.20 (5)	C5^viii—C4—C3	119.66 (18)
O3^vi—Ca1—O1^v	72.21 (5)	C5^viii—C4—C2	119.30 (18)
O5^iv—Ca1—O1^v	75.32 (6)	C3—C4—C2	121.03 (18)
O5—Ca1—O1^v	123.51 (6)	C3—C5—C4^viii	121.39 (18)
O2^iv—Ca1—O1^vi	73.48 (5)	C3—C5—H5	119.3
O2—Ca1—O1^vi	152.50 (5)	C4^viii—C5—H5	119.3
O4^i—Zn1—O1—C1	−44.54 (17)	Ca1^v—O3—C2—O4	−82.2 (3)
O4^ii—Zn1—O1—C1	66.46 (16)	Ca1^v—O3—C2—C4	97.8 (2)
O1^iii—Zn1—O1—C1	−168.66 (17)	Zn1^vii—O4—C2—O3	1.6 (2)
O4^i—Zn1—O1—Ca1^v	−169.11 (6)	Zn1^vii—O4—C2—C4	−178.32 (13)
O4^ii—Zn1—O1—Ca1^v	−58.11 (7)	O2—C1—C3—C5	−77.1 (2)
O1^iii—Zn1—O1—Ca1^v	66.77 (4)	O1—C1—C3—C5	100.1 (2)
O2^iv—Ca1—O2—C1	−96.5 (3)	O2—C1—C3—C4	103.6 (2)
O3^v—Ca1—O2—C1	50.6 (3)	O1—C1—C3—C4	−79.2 (2)
O3^vi—Ca1—O2—C1	140.4 (3)	C5—C3—C4—C5^viii	−0.6 (3)
O5^iv—Ca1—O2—C1	−171.5 (3)	C1—C3—C4—C5^viii	178.61 (17)
O5—Ca1—O2—C1	−20.5 (3)	C5—C3—C4—C2	178.36 (17)
O1^v—Ca1—O2—C1	110.5 (3)	C1—C3—C4—C2	−2.4 (3)
O1^vi—Ca1—O2—C1	−25.9 (4)	O3—C2—C4—C5^viii	176.38 (17)
Ca1—O2—C1—O1	−45.2 (4)	O4—C2—C4—C5^viii	−3.7 (3)
Ca1—O2—C1—C3	131.8 (2)	O3—C2—C4—C3	−2.6 (3)
Zn1—O1—C1—O2	154.42 (16)	O4—C2—C4—C3	177.33 (17)
Ca1^v—O1—C1—O2	−82.4 (2)	C4—C3—C5—C4^viii	0.6 (3)
Zn1—O1—C1—C3	−22.6 (2)	C1—C3—C5—C4^viii	−178.66 (17)
Ca1^v—O1—C1—C3	100.63 (17)

Symmetry codes: (i) x−1, y, z; (ii) −x+1, y, −z−1/2; (iii) −x, y, −z−1/2; (iv) −x+1, y, −z+1/2; (v) −x+1, −y−1, −z; (vi) x, −y−1, z+1/2; (vii) x+1, y, z; (viii) −x+1, −y, −z.

Hydrogen-bond geometry (Å, º)

D—H···A	D—H	H···A	D···A	D—H···A
O6—H6···O4	0.85	2.49	3.255 (4)	151
O5—H5A···O6^viii	0.85	2.11	2.914 (4)	157
O5—H5B···O1^ix	0.85	2.16	2.951 (2)	156

Symmetry codes: (viii) −x+1, −y, −z; (ix) −x, −y−1, −z.