catena-Poly­[[bis(4-cyano­benzoato)copper(II)]-μ-4,4′-bi­pyridine-κ²N:N′]

In the title polymeric complex, [Cu(C₈H₄NO₂)₂(C₁₀H₈N₂)]_n, the Cu^II center is located on an inversion center and surrounded by two N-donor mol­ecules and two 4-cyano­benzoato ligands, which impose a square-planar environment on the metal. The spacer linker, 4,4′-bi­pyridine, is located on an inversion center and links adjacent metal atoms into a one-dimensional chain with a Cu...Cu separation of 11.218 (2) Å.

Key indicators

• Single-crystal X-ray study
• T = 293 K
• Mean [sigma](C-C) = 0.005 Å
• R factor = 0.051
• wR factor = 0.096
• Data-to-parameter ratio = 13.0

checkCIF results

No syntax errors found

ADDSYM reports no extra symmetry


 Alert Level C:



REFLT_03
         From the CIF: _diffrn_reflns_theta_max           28.25
         From the CIF: _reflns_number_total               2504
         TEST2: Reflns within _diffrn_reflns_theta_max
         Count of symmetry unique reflns         2778
         Completeness (_total/calc)             90.14%
          Alert C: < 95% complete

PLAT_213  Alert C Atom N2      has ADP max/min Ratio ...........       3.60 oblate

PLAT_213  Alert C Atom C8      has ADP max/min Ratio ...........       3.10 prolate

PLAT_213  Alert C Atom C9      has ADP max/min Ratio ...........       3.80 prolate

PLAT_371  Alert C Long   C(sp2)-C(sp1) Bond  C(10)  -   C(13)  =       1.44 Ang.

PLAT_731  Alert C Bond    Calc     0.89(4), Rep   0.891(19) ....       2.11 su-Ratio
                     C8   -H5      1.555   1.555


 0 Alert Level A = Potentially serious problem

 0 Alert Level B = Potential problem

 6 Alert Level C = Please check

---

S1. Comment

In recent years, much attention has been paid to in the field of coordination polymers and especially focused on the ligands of 4,4'-bipyridne, terethphate and their derivatives due to their potential applications in gas adsorption, ion exchange and heterogeneous catalysis (Eddaoudi et al., 2002; Moulton & Zaworotko, 2001; Seo et al., 2000). Complexes with 4-cyanobenzoic acid were sparse and recent one suggests that this kind of complexes has strong blue fluorescent emission (Yuan et al., 2001). Moreover complex with the combination of 4-cyanobenzoic acid and 4,4'-bipyridine has not been reported so far. Here, we present the crystal structure of the Cu^II one-dimensional complex, the title compound, (I).

Compound (I) consists of one-dimensional Cu^II complex in which the geometry around the Cu^II ion, located on an inversion center, is best described as a square planar, as can be seen in Fig. 1. The geometry of Cu atom is completed by two O atoms from two 4-cyanobenzoato ligands and two N atoms from two 4,4'-bipyridine. Two benzoate groups and two pyridine rings of 4,4'-bipyridine ligands are respectively located on the opposite sides to minimize repulsion between the ligands. The Cu—O1 bond length [1.9176 (18) Å] is shorter than those of the compounds such as [Cu(py)₂(H₂O)(C₆H₅COO)₂] (Yang et al., 2001) and [Cu(C₆H₅COO)₂(2,2'-bipy)] (Yang et al., 1994). The 4-cyanobenzoate is monodentately coordinated to copper center and the distance of Cu—O2 [2.861 (3) Å] is longer and is considered as non-bonding. This coordination mode of 4-cyanobenzoato ligand results in the four-coordinated copper geometry. The Cu—N1 bond length [2.051 (2) Å] is similar to those of [Cu(py)₂(H₂O)(C₆H₅COO)₂] (Yang et al., 2001) and [Cu(C₆H₅COO)₂(2,2'-bipy)] (Yang et al., 1994) or those of Cu^II complexes with 4,4'-bipyridine bridging linker (Xu et al., 2002; Zhu et al., 2002). The spacer ligand, 4,4'-bipyridine, located on an inversion center, links adjacent Cu atoms and extends the complex into one-dimensional chain along [110] (Fig. 2). The Cu···Cu separation of the network is 11.218 (2) Å, which is normal distance found in related to copper/4,4'-bipyridine complexes. As expected, all other bond distances and angles are within normal range, and in good agreement with those of other 4,4'-bipyridine and carboxyl-containing complexes.

S2. Experimental

The title complex, (I), was synthesized by three layered-solution approach in a tube of ca 0.8 cm diameter with a 20 cm length. The top layer was 10 ml of methanol solution of 4,4'-bipyridine (0.2 mol l⁻¹) and 4-cyanobenzoic acid (0.05 mol l⁻¹). The middle layer was 3 ml of mixed solvents of methanol and water with volume ratio 1:1. The bottom layer was 5 ml of water solution of Cu(NO₃)₂·3H₂O (0.5 mol l⁻¹). After 3 d, crystals of (I) were obtained and filtered out.

S3. Refinement

The completeness was relatively low (90.1%) although all parameters were set according to the suggestions of SMART. The H atoms were refined isotropically. C—H bond lengths are 0.89 (4)–0.92 (2) Å. Atom displacement parameters of N2, C8 and C9 are abnormal. Their displacement ellipsoids are much elongated, suggesting some disorder.

Computing details

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

Figures

	Fig. 1. ORTEP diagram of (I) showing atom labeling scheme. Displacement ellipsoids represent 50% probability.
	Fig. 2. The packing view of the title complex (I).

(I)

Crystal data

[Cu(C8H4NO2)2(C10H8N2)]	Z = 1
Mr = 511.97	F(000) = 261
Triclinic, P1	Dx = 1.507 Mg m^−3
a = 5.3279 (10) Å	Mo Kα radiation, λ = 0.71073 Å
b = 8.9739 (17) Å	Cell parameters from 978 reflections
c = 12.195 (2) Å	θ = 5.3–48.0°
α = 99.734 (3)°	µ = 1.01 mm^−1
β = 92.495 (4)°	T = 293 K
γ = 100.190 (4)°	Plate, blue
V = 563.99 (18) Å^3	0.31 × 0.11 × 0.04 mm

Data collection

Bruker SMART CCD area-detector diffractometer	2504 independent reflections
Radiation source: fine-focus sealed tube	2053 reflections with I > 2σ(I)
Graphite monochromator	Rint = 0.035
ϕ and ω scans	θmax = 28.3°, θmin = 1.7°
Absorption correction: multi-scan (SADABS; Sheldrick, 1996)	h = −7→6
Tmin = 0.820, Tmax = 0.965	k = −11→8
3490 measured reflections	l = −15→15

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)] = 0.051	Hydrogen site location: inferred from neighbouring sites
wR(F^2) = 0.096	All H-atom parameters refined
S = 0.95	w = 1/[σ^2(Fo^2) + (0.0303P)^2] where P = (Fo^2 + 2Fc^2)/3
2504 reflections	(Δ/σ)max = 0.042
192 parameters	Δρmax = 0.43 e Å^−3
4 restraints	Δρmin = −0.36 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
Cu	0.5000	1.0000	0.5000	0.03066 (19)
O1	0.3001 (4)	0.8941 (2)	0.36588 (17)	0.0399 (6)
O2	0.5852 (5)	1.0203 (3)	0.2725 (2)	0.0742 (9)
N1	0.6939 (4)	0.8213 (3)	0.49639 (18)	0.0308 (6)
N2	−0.3402 (9)	0.5813 (6)	−0.2040 (3)	0.146 (2)
C1	0.8993 (6)	0.8275 (4)	0.5667 (2)	0.0352 (8)
C2	1.0204 (5)	0.7063 (3)	0.5704 (2)	0.0346 (7)
C3	0.9394 (5)	0.5677 (3)	0.4988 (2)	0.0283 (6)
C4	0.7315 (6)	0.5622 (4)	0.4239 (3)	0.0364 (8)
C5	0.6167 (6)	0.6875 (3)	0.4257 (2)	0.0362 (8)
C6	0.3881 (6)	0.9305 (4)	0.2763 (3)	0.0414 (8)
C7	0.2254 (6)	0.8525 (4)	0.1706 (3)	0.0417 (8)
C8	0.2956 (10)	0.8816 (7)	0.0725 (4)	0.120 (2)
C9	0.1526 (11)	0.8136 (8)	−0.0273 (4)	0.136 (3)
C10	−0.0661 (8)	0.7126 (5)	−0.0238 (3)	0.0664 (12)
C11	−0.1403 (8)	0.6822 (5)	0.0747 (4)	0.0822 (15)
C12	0.0071 (8)	0.7531 (5)	0.1726 (3)	0.0686 (13)
C13	−0.2206 (9)	0.6389 (6)	−0.1251 (3)	0.0930 (16)
H1	0.958 (5)	0.922 (3)	0.608 (2)	0.031 (8)*
H2	1.152 (4)	0.717 (3)	0.621 (2)	0.046 (9)*
H3	0.664 (5)	0.478 (3)	0.375 (2)	0.026 (7)*
H4	0.475 (5)	0.687 (3)	0.381 (2)	0.032 (8)*
H5	0.445 (5)	0.936 (5)	0.060 (4)	0.107 (16)*
H6	0.212 (8)	0.833 (5)	−0.094 (2)	0.122 (18)*
H7	−0.299 (5)	0.621 (4)	0.075 (3)	0.116 (17)*
H8	−0.056 (7)	0.727 (4)	0.235 (3)	0.080 (14)*

Atomic displacement parameters (Ų)

	U^11	U^22	U^33	U^12	U^13	U^23
Cu	0.0388 (3)	0.0289 (3)	0.0229 (3)	0.0133 (2)	−0.0112 (2)	−0.0031 (2)
O1	0.0500 (13)	0.0380 (13)	0.0294 (11)	0.0175 (10)	−0.0156 (10)	−0.0053 (10)
O2	0.0598 (17)	0.088 (2)	0.0538 (17)	−0.0191 (16)	−0.0205 (14)	−0.0063 (15)
N1	0.0327 (13)	0.0277 (13)	0.0305 (13)	0.0094 (11)	−0.0072 (11)	−0.0002 (11)
N2	0.152 (4)	0.176 (5)	0.065 (3)	−0.041 (4)	−0.064 (3)	−0.016 (3)
C1	0.0375 (17)	0.0291 (17)	0.0340 (17)	0.0070 (14)	−0.0132 (14)	−0.0055 (14)
C2	0.0308 (16)	0.0315 (17)	0.0376 (17)	0.0081 (14)	−0.0160 (14)	−0.0023 (14)
C3	0.0291 (15)	0.0265 (16)	0.0286 (14)	0.0075 (12)	−0.0028 (12)	0.0021 (12)
C4	0.0422 (18)	0.0257 (17)	0.0358 (17)	0.0067 (14)	−0.0165 (15)	−0.0056 (14)
C5	0.0376 (18)	0.0315 (17)	0.0366 (17)	0.0112 (14)	−0.0162 (15)	−0.0020 (14)
C6	0.044 (2)	0.038 (2)	0.0362 (19)	0.0100 (16)	−0.0149 (16)	−0.0063 (15)
C7	0.0432 (19)	0.044 (2)	0.0306 (17)	−0.0002 (16)	−0.0118 (15)	−0.0006 (15)
C8	0.104 (4)	0.171 (6)	0.043 (3)	−0.086 (4)	−0.024 (3)	0.023 (3)
C9	0.130 (5)	0.204 (7)	0.027 (2)	−0.085 (4)	−0.022 (3)	0.020 (3)
C10	0.069 (3)	0.080 (3)	0.033 (2)	−0.007 (2)	−0.022 (2)	−0.006 (2)
C11	0.073 (3)	0.101 (4)	0.045 (2)	−0.041 (3)	−0.017 (2)	0.002 (2)
C12	0.069 (3)	0.089 (3)	0.032 (2)	−0.018 (2)	−0.011 (2)	0.006 (2)
C13	0.099 (3)	0.109 (4)	0.047 (3)	−0.021 (3)	−0.029 (2)	−0.002 (3)

Geometric parameters (Å, º)

Cu—O1	1.9176 (18)	C4—C5	1.369 (4)
Cu—O1^i	1.9176 (18)	C4—H3	0.89 (2)
Cu—N1^i	2.051 (2)	C5—H4	0.92 (2)
Cu—N1	2.051 (2)	C6—C7	1.511 (4)
O1—C6	1.277 (4)	C7—C8	1.323 (6)
O2—C6	1.214 (4)	C7—C12	1.339 (5)
N1—C5	1.341 (3)	C8—C9	1.392 (6)
N1—C1	1.347 (3)	C8—H5	0.891 (19)
N2—C13	1.123 (4)	C9—C10	1.350 (6)
C1—C2	1.365 (4)	C9—H6	0.911 (19)
C1—H1	0.90 (3)	C10—C11	1.337 (6)
C2—C3	1.380 (4)	C10—C13	1.443 (4)
C2—H2	0.895 (16)	C11—C12	1.390 (5)
C3—C4	1.393 (3)	C11—H7	0.922 (19)
C3—C3^ii	1.478 (5)	C12—H8	0.89 (4)
O1—Cu—O1^i	180.000 (1)	C4—C5—H4	123.5 (17)
O1—Cu—N1^i	89.83 (8)	O2—C6—O1	124.6 (3)
O1^i—Cu—N1^i	90.17 (8)	O2—C6—C7	120.6 (3)
O1—Cu—N1	90.17 (8)	O1—C6—C7	114.8 (3)
O1^i—Cu—N1	89.83 (8)	C8—C7—C12	117.8 (3)
N1^i—Cu—N1	180.000 (1)	C8—C7—C6	120.4 (3)
C6—O1—Cu	114.5 (2)	C12—C7—C6	121.8 (3)
C5—N1—C1	115.6 (2)	C7—C8—C9	122.8 (5)
C5—N1—Cu	121.49 (17)	C7—C8—H5	126 (3)
C1—N1—Cu	122.85 (19)	C9—C8—H5	111 (3)
N1—C1—C2	123.6 (3)	C10—C9—C8	118.6 (5)
N1—C1—H1	113.5 (16)	C10—C9—H6	121 (3)
C2—C1—H1	122.7 (16)	C8—C9—H6	120 (3)
C1—C2—C3	120.9 (2)	C11—C10—C9	119.4 (4)
C1—C2—H2	118.8 (19)	C11—C10—C13	120.0 (4)
C3—C2—H2	120.3 (19)	C9—C10—C13	120.6 (4)
C2—C3—C4	115.6 (3)	C10—C11—C12	120.3 (4)
C2—C3—C3^ii	122.9 (3)	C10—C11—H7	117 (3)
C4—C3—C3^ii	121.4 (3)	C12—C11—H7	122 (3)
C5—C4—C3	120.4 (3)	C7—C12—C11	121.1 (4)
C5—C4—H3	117.3 (16)	C7—C12—H8	124 (2)
C3—C4—H3	122.2 (16)	C11—C12—H8	115 (2)
N1—C5—C4	123.8 (2)	N2—C13—C10	179.7 (6)
N1—C5—H4	112.7 (16)

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