catena-Poly[[diaqua­copper(II)]-μ-2,2′-bi­pyridine-3,3′-dicarboxyl­ate]

In the title compound, [Cu(C₁₂H₆N₂O₄)(H₂O)₂]_n, the 2,2′-bipyridine-3,3′-dicarboxyl­ate (dcbp) dianion lies on a twofold rotation axis. The Cu atom also lies on this axis and is coordinated by two N atoms and two O atoms of two bridging dcbp ligands in the equatorial plane. Two aqua ligands complete the distorted cis-CuN₂O₄ octa­hedral coordination of the Cu atom. O—H...O hydrogen bonds help to stabilize the structure.

Key indicators

• Single-crystal X-ray study
• T = 298 K
• Mean [sigma](C-C) = 0.005 Å
• R factor = 0.038
• wR factor = 0.130
• Data-to-parameter ratio = 10.0

checkCIF/PLATON results

No syntax errors found



Alert level C
PLAT062_ALERT_4_C Rescale T(min) & T(max) by .....................       0.99
PLAT232_ALERT_2_C Hirshfeld Test Diff (M-X)  Cu1    -   O1      ..       5.57 su
PLAT720_ALERT_4_C Number of Unusual/Non-Standard Label(s) ........          2

Alert level G
PLAT860_ALERT_3_G Note: Number of Least-Squares Restraints .......          3

   0 ALERT level A = In general: serious problem
   0 ALERT level B = Potentially serious problem
   3 ALERT level C = Check and explain
   1 ALERT level G = General alerts; check

   0 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
   2 ALERT type 4 Improvement, methodology, query or suggestion
   0 ALERT type 5 Informative message, check

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S1. Comment

Transition metal complexes with 2,2'-bipyridine derivatives can serve as models for the study of excited state dynamics. In addition, they are of interest for the development of light-energy conversion devices and optical sensors. One of the simplest carbonyl-containing derivatives of 2,2'-bipyridine is 3,3'-dicarboxy-2,2'-bipyridine (dcbp) which has two available centres for complexation: the nitrogen atoms of bipyridine fragment and the oxygen atoms of the carboxylic groups. (Starova et al., 2007). In this paper, we report the synthesis and crystal structure of the title complex, (I), (Fig. 1).

In (I), the copper atom (site symmetry 2) is bridged by two N atoms and two O atoms of two dcbp ligands in the basal plane. The remaining positions are occupied by two water molecules and complete the octahedral coordination sphere of Cu atom (Table 1). The dcbp ligands link the neighboring Cu ions via two carboxlate groups forming an infinite chain.

The structure of (I) is completed by O—H···O hydrogen bonds (Table 2).

Related literature

For related literature, see: Starova et al. (2007).

S2. Experimental

CuCl₂ (0.011 g, 0.0095 mmol), H₂dcbp (0.013 g, 0.011 mmol) and NaOH (0.047 g, 0.12 mmol), were added to a mixed solvent of ethanol and acetonitrile, and the mixture was heated for five hours under reflux with stirring. The resultant was then filtered to give a solution which was infiltrated by diethyl ether in a closed vessel. After one week, blue blocks of (I) were recovered.

S3. Refinement

The H atoms (pyridine ring) were placed in calculated positions [Csp²—H = 0.93 Å] and refined as riding with U_iso(H) = 1.2U_eq(C). The water H atoms were found in a dfference map (O—H = 0.86 Å), with U_iso(H) = 1.5U_eq(C).

Computing details

Data collection: APEX2 (Bruker, 2004); cell refinement: SAINT (Bruker, 2004); data reduction: SAINT; program(s) used to solve structure: SHELXS97 (Sheldrick, 1997); program(s) used to refine structure: SHELXL97 (Sheldrick, 1997); molecular graphics: SHELXTL (Bruker, 2004); software used to prepare material for publication: SHELXTL.

Figures

Fig. 1. A fragemnt of the chain structure of (I) showing 30% probability displacement ellipsoids (arbitrary spheres for the H atoms). Symmetry codes: (i) 1 - x, y, 1/2 - z; (ii) x, y + 1, z; (iii) 1 - x, y - 1, 1/2 - z; (iv) x, y - 1, z.

catena-Poly[[diaquacopper(II)]-µ-2,2'-bipyridine-3,3'-dicarboxylate]

Crystal data

[Cu(C12H6N2O4)(H2O)2]	F(000) = 692
Mr = 341.76	Dx = 1.970 Mg m^−3
Monoclinic, C2/c	Mo Kα radiation, λ = 0.71073 Å
Hall symbol: -C 2yc	Cell parameters from 1044 reflections
a = 11.3254 (15) Å	θ = 3.2–25.2°
b = 7.8829 (10) Å	µ = 1.93 mm^−1
c = 13.1264 (17) Å	T = 298 K
β = 100.519 (2)°	Block, blue
V = 1152.2 (3) Å^3	0.31 × 0.19 × 0.14 mm
Z = 4

Data collection

Bruker APEX-II CCD diffractometer	1044 independent reflections
Radiation source: fine-focus sealed tube	1007 reflections with I > 2σ(I)
Graphite monochromator	Rint = 0.039
Detector resolution: 0 pixels mm^-1	θmax = 25.2°, θmin = 3.2°
ϕ and ω scan	h = −13→11
Absorption correction: multi-scan (SADABS; Sheldrick, 2004)	k = −9→9
Tmin = 0.586, Tmax = 0.774	l = −15→15
2925 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)] = 0.038	Hydrogen site location: inferred from neighbouring sites
wR(F^2) = 0.130	H atoms treated by a mixture of independent and constrained refinement
S = 0.86	w = 1/[σ^2(Fo^2) + (0.1078P)^2 + 11.1055P] where P = (Fo^2 + 2Fc^2)/3
1044 reflections	(Δ/σ)max < 0.001
104 parameters	Δρmax = 0.60 e Å^−3
3 restraints	Δρmin = −0.44 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
O2	0.4605 (2)	1.0082 (3)	0.13881 (18)	0.0102 (5)
C6	0.5228 (3)	0.8739 (4)	0.1493 (2)	0.0089 (7)
Cu1	0.5000	0.20313 (7)	0.2500	0.0146 (3)
O1	0.3250 (2)	0.1907 (3)	0.2842 (2)	0.0119 (6)
O3	0.6348 (2)	0.8655 (3)	0.17267 (19)	0.0129 (6)
N1	0.4346 (2)	0.4120 (4)	0.1575 (2)	0.0089 (6)
C1	0.3728 (3)	0.3938 (4)	0.0607 (3)	0.0113 (7)
H1	0.3488	0.2856	0.0372	0.014*
C2	0.3433 (3)	0.5301 (4)	−0.0057 (3)	0.0126 (7)
H2	0.2944	0.5164	−0.0702	0.015*
C3	0.3893 (3)	0.6873 (4)	0.0274 (3)	0.0104 (7)
H3	0.3751	0.7802	−0.0168	0.012*
C4	0.4571 (3)	0.7073 (4)	0.1271 (3)	0.0076 (7)
C5	0.4708 (3)	0.5671 (4)	0.1933 (2)	0.0077 (7)
H1WA	0.265 (2)	0.232 (4)	0.242 (3)	0.022 (12)*
H1WB	0.311 (3)	0.088 (2)	0.301 (3)	0.027 (13)*

Atomic displacement parameters (Ų)

	U^11	U^22	U^33	U^12	U^13	U^23
O2	0.0115 (12)	0.0049 (12)	0.0126 (12)	0.0014 (9)	−0.0022 (9)	−0.0005 (9)
C6	0.0141 (16)	0.0069 (16)	0.0057 (14)	−0.0012 (13)	0.0017 (12)	0.0001 (12)
Cu1	0.0149 (4)	0.0106 (4)	0.0174 (4)	0.000	0.0007 (3)	0.000
O1	0.0077 (12)	0.0093 (13)	0.0185 (14)	0.0013 (9)	0.0018 (10)	0.0032 (9)
O3	0.0094 (12)	0.0088 (12)	0.0193 (13)	0.0003 (9)	−0.0005 (10)	0.0003 (10)
N1	0.0085 (13)	0.0074 (14)	0.0101 (14)	0.0003 (11)	−0.0001 (11)	−0.0008 (11)
C1	0.0094 (16)	0.0097 (16)	0.0137 (16)	−0.0015 (12)	−0.0003 (13)	−0.0027 (13)
C2	0.0117 (16)	0.0139 (18)	0.0111 (16)	0.0008 (14)	−0.0008 (13)	−0.0030 (13)
C3	0.0088 (17)	0.0122 (17)	0.0094 (17)	0.0030 (12)	−0.0006 (13)	−0.0002 (12)
C4	0.0068 (16)	0.0058 (17)	0.0102 (17)	0.0020 (11)	0.0017 (13)	−0.0021 (11)
C5	0.0068 (15)	0.0074 (15)	0.0087 (17)	−0.0001 (12)	0.0013 (12)	−0.0019 (12)

Geometric parameters (Å, º)

O2—C6	1.266 (4)	O1—H1WB	0.86 (2)
O2—Cu1^i	2.111 (2)	N1—C1	1.342 (5)
C6—O3	1.250 (4)	N1—C5	1.346 (4)
C6—C4	1.511 (4)	C1—C2	1.385 (5)
Cu1—N1^ii	2.099 (3)	C1—H1	0.9300
Cu1—N1	2.099 (3)	C2—C3	1.383 (5)
Cu1—O2^iii	2.111 (2)	C2—H2	0.9300
Cu1—O2^iv	2.111 (2)	C3—C4	1.400 (5)
Cu1—O1	2.113 (2)	C3—H3	0.9300
Cu1—O1^ii	2.113 (2)	C4—C5	1.397 (5)
O1—H1WA	0.86 (3)	C5—C5^ii	1.516 (6)
C6—O2—Cu1^i	119.4 (2)	Cu1—O1—H1WB	108 (3)
O3—C6—O2	126.3 (3)	H1WA—O1—H1WB	111 (3)
O3—C6—C4	116.3 (3)	C1—N1—C5	120.0 (3)
O2—C6—C4	117.4 (3)	C1—N1—Cu1	122.1 (2)
N1^ii—Cu1—N1	76.66 (15)	C5—N1—Cu1	117.2 (2)
N1^ii—Cu1—O2^iii	168.28 (10)	N1—C1—C2	122.5 (3)
N1—Cu1—O2^iii	99.40 (10)	N1—C1—H1	118.8
N1^ii—Cu1—O2^iv	99.40 (10)	C2—C1—H1	118.8
N1—Cu1—O2^iv	168.28 (10)	C3—C2—C1	117.6 (3)
O2^iii—Cu1—O2^iv	86.52 (13)	C3—C2—H2	121.2
N1^ii—Cu1—O1	99.16 (10)	C1—C2—H2	121.2
N1—Cu1—O1	85.03 (10)	C2—C3—C4	120.4 (3)
O2^iii—Cu1—O1	91.41 (10)	C2—C3—H3	119.8
O2^iv—Cu1—O1	84.71 (9)	C4—C3—H3	119.8
N1^ii—Cu1—O1^ii	85.03 (10)	C5—C4—C3	118.1 (3)
N1—Cu1—O1^ii	99.16 (10)	C5—C4—C6	125.0 (3)
O2^iii—Cu1—O1^ii	84.71 (9)	C3—C4—C6	116.4 (3)
O2^iv—Cu1—O1^ii	91.41 (9)	N1—C5—C4	120.7 (3)
O1—Cu1—O1^ii	174.69 (13)	N1—C5—C5^ii	113.15 (19)
Cu1—O1—H1WA	121 (3)	C4—C5—C5^ii	126.1 (2)

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

Hydrogen-bond geometry (Å, º)

D—H···A	D—H	H···A	D···A	D—H···A
O1—H1WB···O3^iv	0.86 (3)	1.87 (2)	2.647 (3)	150 (4)
O1—H1WA···O3^v	0.86 (2)	1.90 (3)	2.744 (3)	167 (4)

Symmetry codes: (iv) −x+1, y−1, −z+1/2; (v) x−1/2, y−1/2, z.