catena-Poly[[triaqua-cadmium(II)]-μ-pyridine-2,3-dicarboxyl-ato-κN,O:O].

The title polymeric compound, [Cd(C(7)H(3)NO(4))(H(2)O)(3)](n) or [Cd(py-2,3-dc)(H(2)O)(3)](n), where py-2,3-dcH(2) is pyridine-2,3-dicarboxylic acid, was obtained by the reaction of cadmium(II) nitrate hexa-hydrate with (pipzH(2))(py-2,3-dc) as a proton-transfer compound in aqueous solution (pipz is piperazine). The mol-ecular structure shows that only the anionic fragment of the starting proton-transfer compound is present in the complex, while the (pipzH(2))(2+) dication has been lost. Each (py-2,3-dc)(2-) ligand bridges two Cd(II) atoms in two different coordination modes, i.e. one end acts as a monodentate and the other end as a bidentate ligand. The three remaining coordination sites on the metal center are occupied by water mol-ecules. The geometric arrangement of the six donor atoms around the Cd(II) atom is distorted octa-hedral. In the crystal structure, O-H⋯O and C-H⋯O hydrogen bonds play an important role in stabilizing the supra-molecular structure.

Related literature

For related ion pairs or complexes, see: Aghabozorg, Daneshvar, Motyeian et al. (2007 ▶); Aghabozorg et al. (2008 ▶); Manteghi et al. (2007 ▶); Aghabozorg, Sadr-khanlou et al. (2007 ▶); Li et al. (2004 ▶).

Experimental

Crystal data

[Cd(C7H3NO4)(H2O)3]

M = 331.55

Orthorhombic,

a = 16.820 (3) Å

b = 6.8076 (14) Å

c = 8.6658 (17) Å

V = 992.3 (3) Å3

Z = 4

Mo Kα radiation

μ = 2.22 mm−1

T = 100 (2) K

0.40 × 0.08 × 0.05 mm

Data collection

Bruker APEX 1000 CCD area-detector diffractometer

Absorption correction: multi-scan (APEX2; Bruker, 2005 ▶) T min = 0.810, T max = 0.901

8990 measured reflections

2255 independent reflections

1848 reflections with I > 2σ(I)

R int = 0.060

Refinement

R[F 2 > 2σ(F 2)] = 0.029

wR(F 2) = 0.056

S = 1.01

2255 reflections

151 parameters

7 restraints

H atoms treated by a mixture of independent and constrained refinement

Δρmax = 0.61 e Å−3

Δρmin = −0.84 e Å−3

Absolute structure: Flack (1983), 1042 Friedel pairs

Flack parameter: 0.05 (4)

Data collection: APEX2 (Bruker, 2005 ▶); cell refinement: APEX2; data reduction: APEX2; program(s) used to solve structure: SHELXTL (Sheldrick, 1998 ▶); program(s) used to refine structure: SHELXTL; molecular graphics: SHELXTL; software used to prepare material for publication: SHELXTL.

Crystal structure: contains datablocks I, global. DOI: 10.1107/S160053680706850X/su2028sup1.cif

Structure factors: contains datablocks I. DOI: 10.1107/S160053680706850X/su2028Isup2.hkl

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

[Cd(C7H3NO4)(H2O)3]	F000 = 648
Mr = 331.55	Dx = 2.219 Mg m−3
Orthorhombic, Pca21	Mo Kα radiation λ = 0.71073 Å
Hall symbol: P 2c -2ac	Cell parameters from 1136 reflections
a = 16.820 (3) Å	θ = 3.0–24.6º
b = 6.8076 (14) Å	µ = 2.22 mm−1
c = 8.6658 (17) Å	T = 100 (2) K
V = 992.3 (3) Å3	Needle, colourless
Z = 4	0.40 × 0.08 × 0.05 mm

Bruker APEX 1000 CCD area-detector diffractometer	2255 independent reflections
Radiation source: fine-focus sealed tube	1848 reflections with I > 2σ(I)
Monochromator: graphite	Rint = 0.060
T = 100(2) K	θmax = 27.5º
ω scans	θmin = 2.4º
Absorption correction: multi-scan(APEX2; Bruker, 2005)	h = −21→21
Tmin = 0.810, Tmax = 0.901	k = −8→8
8990 measured reflections	l = −11→11

Refinement on F2	Hydrogen site location: difference Fourier map
Least-squares matrix: full	H atoms treated by a mixture of independent and constrained refinement
R[F2 > 2σ(F2)] = 0.029	w = 1/[σ2(Fo2) + (0.02P)2] where P = (Fo2 + 2Fc2)/3
wR(F2) = 0.056	(Δ/σ)max = 0.001
S = 1.01	Δρmax = 0.61 e Å−3
2255 reflections	Δρmin = −0.84 e Å−3
151 parameters	Extinction correction: none
7 restraints	Absolute structure: Flack (1983), 1042 Friedel pairs
Primary atom site location: structure-invariant direct methods	Flack parameter: 0.05 (4)
Secondary atom site location: difference Fourier map

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
Cd1	0.602315 (16)	0.57263 (4)	1.12348 (5)	0.01148 (8)
O1	0.64375 (15)	0.5438 (4)	1.6269 (10)	0.0146 (4)
O2	0.77114 (19)	0.4893 (5)	1.6812 (4)	0.0146 (4)
O3	0.55536 (18)	0.9159 (5)	1.5507 (4)	0.0139 (7)
O4	0.56140 (18)	0.7169 (5)	1.3472 (4)	0.0131 (8)
C1	0.7384 (3)	0.7512 (7)	1.5083 (6)	0.0114 (10)
C2	0.6813 (3)	0.8656 (7)	1.4333 (6)	0.0120 (11)
C3	0.7065 (3)	1.0220 (8)	1.3431 (7)	0.0110 (11)
H3A	0.6685	1.1023	1.2920	0.013*
C4	0.7868 (3)	1.0616 (8)	1.3272 (7)	0.0149 (11)
H4A	0.8050	1.1660	1.2636	0.018*
C5	0.8403 (3)	0.9424 (8)	1.4080 (6)	0.0168 (11)
H5A	0.8956	0.9694	1.4001	0.020*
C6	0.7166 (2)	0.5813 (6)	1.6146 (9)	0.0146 (4)
C7	0.5934 (3)	0.8271 (7)	1.4475 (5)	0.0113 (10)
N1	0.8168 (2)	0.7919 (6)	1.4961 (5)	0.0125 (9)
O1W	0.5482 (2)	0.2964 (6)	1.2211 (4)	0.0145 (8)
H1	0.526 (3)	0.302 (9)	1.309 (4)	0.022*
H2	0.509 (2)	0.227 (7)	1.183 (5)	0.022*
O2W	0.47743 (19)	0.6981 (5)	1.0383 (4)	0.0134 (7)
H3	0.439 (2)	0.618 (6)	1.065 (6)	0.020*
H4	0.464 (3)	0.818 (4)	1.060 (6)	0.020*
O3W	0.59058 (19)	0.3963 (5)	0.9018 (4)	0.0147 (8)
H5	0.5445 (19)	0.350 (8)	0.879 (7)	0.022*
H6	0.609 (3)	0.420 (8)	0.811 (3)	0.022*

	U11	U22	U33	U12	U13	U23
Cd1	0.00902 (12)	0.01505 (14)	0.01036 (13)	−0.00047 (13)	0.0004 (3)	0.0018 (3)
O1	0.0109 (8)	0.0186 (11)	0.0144 (10)	0.0005 (8)	0.0029 (11)	0.0048 (12)
O2	0.0109 (8)	0.0186 (11)	0.0144 (10)	0.0005 (8)	0.0029 (11)	0.0048 (12)
O3	0.0112 (16)	0.0158 (18)	0.0146 (16)	−0.0006 (14)	0.0041 (13)	−0.0032 (16)
O4	0.0077 (16)	0.023 (2)	0.0084 (17)	−0.0019 (14)	0.0004 (14)	−0.0031 (16)
C1	0.011 (2)	0.012 (3)	0.011 (2)	−0.0042 (19)	−0.0063 (19)	−0.001 (2)
C2	0.010 (2)	0.014 (3)	0.012 (3)	−0.0018 (19)	0.000 (2)	−0.005 (2)
C3	0.009 (3)	0.013 (3)	0.011 (3)	0.004 (2)	0.000 (2)	−0.002 (2)
C4	0.014 (3)	0.016 (3)	0.014 (3)	−0.002 (2)	−0.001 (2)	0.005 (3)
C5	0.012 (3)	0.020 (3)	0.017 (3)	−0.004 (2)	0.000 (2)	−0.004 (3)
C6	0.0109 (8)	0.0186 (11)	0.0144 (10)	0.0005 (8)	0.0029 (11)	0.0048 (12)
C7	0.013 (2)	0.011 (3)	0.010 (2)	−0.001 (2)	−0.003 (2)	0.0057 (19)
N1	0.011 (2)	0.016 (2)	0.010 (2)	−0.0057 (17)	0.0018 (16)	−0.0007 (18)
O1W	0.0142 (18)	0.022 (2)	0.0070 (17)	−0.0081 (15)	0.0020 (14)	−0.0012 (16)
O2W	0.0127 (17)	0.0119 (19)	0.0156 (19)	0.0014 (14)	−0.0030 (14)	−0.0008 (17)
O3W	0.0113 (18)	0.023 (2)	0.0093 (16)	−0.0033 (15)	0.0003 (14)	−0.0040 (16)

Cd1—O1W	2.254 (4)	C2—C7	1.506 (6)
Cd1—O2i	2.259 (3)	C3—C4	1.385 (6)
Cd1—O3W	2.274 (3)	C3—H3A	0.9500
Cd1—O4	2.279 (3)	C4—C5	1.400 (7)
Cd1—N1i	2.302 (4)	C4—H4A	0.9500
Cd1—O2W	2.385 (3)	C5—N1	1.338 (7)
O1—C6	1.256 (4)	C5—H5A	0.9500
O2—C6	1.252 (6)	N1—Cd1ii	2.302 (4)
O2—Cd1ii	2.259 (3)	O1W—H1	0.850 (19)
O3—C7	1.255 (6)	O1W—H2	0.869 (19)
O4—C7	1.268 (6)	O2W—H3	0.88 (2)
C1—N1	1.351 (6)	O2W—H4	0.866 (19)
C1—C2	1.397 (7)	O3W—H5	0.858 (19)
C1—C6	1.523 (7)	O3W—H6	0.87 (2)
C2—C3	1.387 (7)
O1W—Cd1—O2i	95.06 (13)	C2—C3—H3A	119.9
O1W—Cd1—O3W	80.89 (13)	C3—C4—C5	117.7 (5)
O2i—Cd1—O3W	97.84 (12)	C3—C4—H4A	121.1
O1W—Cd1—O4	85.31 (13)	C5—C4—H4A	121.1
O2i—Cd1—O4	101.79 (12)	N1—C5—C4	122.6 (5)
O3W—Cd1—O4	156.89 (12)	N1—C5—H5A	118.7
O1W—Cd1—N1i	163.70 (14)	C4—C5—H5A	118.7
O2i—Cd1—N1i	73.25 (13)	O2—C6—O1	125.0 (6)
O3W—Cd1—N1i	89.34 (14)	O2—C6—C1	118.8 (4)
O4—Cd1—N1i	107.87 (14)	O1—C6—C1	116.2 (5)
O1W—Cd1—O2W	93.38 (13)	O3—C7—O4	123.9 (4)
O2i—Cd1—O2W	171.30 (12)	O3—C7—C2	118.3 (4)
O3W—Cd1—O2W	81.44 (12)	O4—C7—C2	117.6 (4)
O4—Cd1—O2W	80.96 (12)	C5—N1—C1	119.4 (4)
N1i—Cd1—O2W	98.06 (13)	C5—N1—Cd1ii	126.5 (3)
C6—O2—Cd1ii	117.6 (3)	C1—N1—Cd1ii	114.0 (3)
C7—O4—Cd1	135.2 (3)	Cd1—O1W—H1	118 (4)
N1—C1—C2	121.3 (5)	Cd1—O1W—H2	128 (3)
N1—C1—C6	116.0 (4)	H1—O1W—H2	92 (5)
C2—C1—C6	122.6 (4)	Cd1—O2W—H3	110 (3)
C3—C2—C1	118.7 (4)	Cd1—O2W—H4	120 (4)
C3—C2—C7	118.6 (4)	H3—O2W—H4	110 (5)
C1—C2—C7	122.7 (4)	Cd1—O3W—H5	118 (4)
C4—C3—C2	120.2 (5)	Cd1—O3W—H6	130 (4)
C4—C3—H3A	119.9	H5—O3W—H6	101 (5)
O1W—Cd1—O4—C7	131.6 (5)	C2—C1—C6—O2	−177.9 (5)
O2i—Cd1—O4—C7	37.4 (5)	N1—C1—C6—O1	179.6 (6)
O3W—Cd1—O4—C7	−175.1 (4)	C2—C1—C6—O1	2.7 (9)
N1i—Cd1—O4—C7	−38.6 (5)	Cd1—O4—C7—O3	168.0 (3)
O2W—Cd1—O4—C7	−134.3 (5)	Cd1—O4—C7—C2	−7.0 (7)
N1—C1—C2—C3	0.9 (7)	C3—C2—C7—O3	−87.1 (6)
C6—C1—C2—C3	177.6 (5)	C1—C2—C7—O3	92.4 (6)
N1—C1—C2—C7	−178.5 (4)	C3—C2—C7—O4	88.2 (6)
C6—C1—C2—C7	−1.8 (8)	C1—C2—C7—O4	−92.3 (6)
C1—C2—C3—C4	0.6 (9)	C4—C5—N1—C1	0.2 (8)
C7—C2—C3—C4	−179.9 (5)	C4—C5—N1—Cd1ii	176.0 (4)
C2—C3—C4—C5	−1.7 (9)	C2—C1—N1—C5	−1.3 (7)
C3—C4—C5—N1	1.3 (9)	C6—C1—N1—C5	−178.3 (5)
Cd1ii—O2—C6—O1	175.2 (6)	C2—C1—N1—Cd1ii	−177.7 (4)
Cd1ii—O2—C6—C1	−4.1 (7)	C6—C1—N1—Cd1ii	5.4 (6)
N1—C1—C6—O2	−1.0 (8)

D—H···A	D—H	H···A	D···A	D—H···A
O1W—H1···O2Wiii	0.85 (2)	1.99 (2)	2.782 (5)	155.61
O1W—H2···O3iv	0.87 (2)	1.86 (2)	2.702 (5)	163.55
O2W—H3···O1iv	0.88 (2)	1.85 (2)	2.731 (5)	177.88
O2W—H4···O3v	0.87 (2)	1.84 (2)	2.687 (5)	164.45
O3W—H5···O4iv	0.86 (2)	1.86 (2)	2.712 (4)	171.29
O3W—H6···O1vi	0.87 (2)	1.89 (2)	2.735 (8)	164.32
C3—H3A···O1Wvii	0.95 (2)	2.49 (2)	3.420 (6)	165

Cd1—O1W	2.254 (4)
Cd1—O2i	2.259 (3)
Cd1—O3W	2.274 (3)
Cd1—O4	2.279 (3)
Cd1—N1i	2.302 (4)
Cd1—O2W	2.385 (3)

O3W—Cd1—O4	156.89 (12)
O1W—Cd1—N1i	163.70 (14)
O2i—Cd1—O2W	171.30 (12)

Symmetry code: (i) .

Table 2

Hydrogen-bond geometry (Å, °)

D—H⋯A	D—H	H⋯A	D⋯A	D—H⋯A
O1W—H1⋯O2Wii	0.85 (2)	1.99 (2)	2.782 (5)	155.61
O1W—H2⋯O3iii	0.87 (2)	1.86 (2)	2.702 (5)	163.55
O2W—H3⋯O1iii	0.88 (2)	1.85 (2)	2.731 (5)	177.88
O2W—H4⋯O3iv	0.87 (2)	1.84 (2)	2.687 (5)	164.45
O3W—H5⋯O4iii	0.86 (2)	1.86 (2)	2.712 (4)	171.29
O3W—H6⋯O1v	0.87 (2)	1.89 (2)	2.735 (8)	164.32
C3—H3A⋯O1Wvi	0.95 (2)	2.49 (2)	3.420 (6)	165

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