metal-organic compounds
Bis(methacrylato-κO)bis(2,4,6-trimethylpyridine-κN)copper(II)
aMaterials Chemistry Laboratry, Department of Chemistry, GC University, Lahore 54000, Pakistan, and bDepartment of Chemistry, University of Aberdeen, Meston Walk, Aberdeen AB24 3UE, Scotland
*Correspondence e-mail: iuklodhi@yahoo.com
In the monomeric title complex, [Cu(C4H5O2)2(C8H11N)2], the CuII atom lies on a centre of inversion. Its coordination by two substituted pyridine ligands and two carboxylate anions leads to a slightly distorted trans-CuN2O2 square-planar geometry. The dihedral angle between the mean planes of the pyridine (py) ring and the carboxylate group is 74.71 (7)°. The dihedral angles between the planar CuN2O2 core and the py ring and carboxylate plane are 67.72 (5) and 89.95 (5)°, respectively. Based on the refined C=C and C—C bond lengths, the terminal =CH2 and –CH3 groups of the carboxylate anion may be disordered, but the disorder could not be resolved in the present experiment. Several intramolecular C—H⋯O interactions occur. In the crystal, molecules are linked by weak C—H⋯O hydrogen bonds, generating chains propagating in [100].
Related literature
For the crystal structures of related monomeric complexes containing a trans-CuN2O2 core, see: Borel et al. (1981); Heimer & Ahmed (1982); Jedrzejas et al. (1994).
Experimental
Crystal data
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Refinement
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Data collection: APEX2 (Bruker, 2007); cell SAINT (Bruker, 2007); data reduction: SAINT; program(s) used to solve structure: SHELXS97 (Sheldrick, 2008); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008); molecular graphics: ORTEP-3 (Farrugia, 1997); software used to prepare material for publication: SHELXL97.
Supporting information
10.1107/S1600536812009919/rn2095sup1.cif
contains datablocks I, global. DOI:Structure factors: contains datablock I. DOI: 10.1107/S1600536812009919/rn2095Isup2.hkl
Copper sulfate (0.16 g, 1.0 mmol) was dissolved in methanol (20 ml). Then, 2,4,6-trimethyl pyridine (0.264 ml, 2.0 mmol) was added to this solution, which turned green. This reaction mixture was refluxed for 30 minutes followed by addition of methacrylic acid (0.169 ml, 2.0 mmol), at which point the solution remained green. After refluxing for one hour, the solution was filtered and kept for a few days. Blue-green blocks of (I) were obtained from filtrate by slow evaporation.
Attempts were made to represent the disordered C11 (nominal CH2 group) and C12 (nominal CH3 group) atoms with a double-site model, but the
was unstable. The hydrogen atoms were placed in calculated positions (C—H = 0.93–0.96Å) and refined as riding atoms with Uiso(H) = 1.2Ueq(C) or 1.5Ueq(methyl C). The methyl groups were allowed to rotate, but not to tip, to best fit the electron density.The title compound, (I), is a centrosymmetric neutral monomeric copper(II) complex (Fig. 1). Related structures containing a copper(II) ion bonded to a pair of susbtituted pyridine ligands and a pair of monodentate carboxylate anions have been described previously (Borel et al., 1981; Heimer & Ahmed, 1982; Jedrzejas et al., 1994).
The Cu ion in (I) lies on an inversion centre, resulting in a slightly distorted trans-CuN2O2 square planar geometry for the metal ion (Table 1). If a very long contact between Cu1 and O1 [2.8229 (17)Å] is considered to have any significance as a bond, a grossly disorted trans-CuN2O4 octahedron results. The mean planes of the pyridine ring (r.m.s. deviation = 0.0099Å) and the carboxylate group (r.m.s. deviation = 0.0003Å) are roughly perpendicular [dihedral angle = 74.71 (7)°], which presumably minimises steric interactions between the ligands. The dihedral angles between the planar CuN2O2 core and the py ring and carboxylate plane are are 67.72 (5) and 89.95 (5)°, respectively. The Cu ion is displaced by 0.256 (3)Å from the py ring plane and by 0.252 (3)Å from the carboxylate plane. The carboxylate C—O bond lengths of 1.222 (2)Å for O1 and 1.276 (2)Å for O2 suggest the presence of relatively localised single and double bonds in the anion.
The terminal CH2 and CH3 groups of the carboxylate anion are probably disordered: the nominal C10—C11 single bond is short [1.422 (4)Å] and the nominal C10=C12 double bond is long [1.378 (4)Å]. This may also correlate with the Hirshfeld rigid bond alert for the C10—C12 bond. The presumed disorder could not be resolved in the present experiment. Several intramolecular C—H···O interactions occur (Table 1). In the crystal, the molecules are linked by C—H···O hydrogen bonds to generate chains in the [100] direction.
In trans-bis(acetato-O)bis(4-methyl pyridine-N)copper(II) (Jedrzejas et al., 1994), (II), the dihedral angle between the ligands is 78.2° (s.u. not stated), and the dihedral angle between the py ring and the CuN2O2 plane is 31.6°. The uncoordinated Cu···O separation of 2.623 (4)Å in (II) is significantly shorter than that seen in (I). However, it is notable that the carboxylate C—O bonds lengths in (II) [1.227 (7) and 1.279 (6)Å] are almost identical to those seen here.
For the crystal structures of related monomeric complexes containing a trans-CuN2O2 core, see: Borel et al. (1981); Heimer & Ahmed (1982); Jedrzejas et al. (1994).
Data collection: APEX2 (Bruker, 2007); cell
SAINT (Bruker, 2007); data reduction: SAINT (Bruker, 2007); program(s) used to solve structure: SHELXS97 (Sheldrick, 2008); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008); molecular graphics: ORTEP-3 (Farrugia, 1997); software used to prepare material for publication: SHELXL97 (Sheldrick, 2008).[Cu(C4H5O2)2(C8H11N)2] | F(000) = 502 |
Mr = 476.06 | Dx = 1.298 Mg m−3 |
Monoclinic, P21/n | Mo Kα radiation, λ = 0.71073 Å |
Hall symbol: -P 2yn | Cell parameters from 3020 reflections |
a = 8.2295 (2) Å | θ = 2.4–28.3° |
b = 17.0921 (6) Å | µ = 0.93 mm−1 |
c = 9.1683 (3) Å | T = 296 K |
β = 109.220 (1)° | Block, blue-green |
V = 1217.73 (7) Å3 | 0.08 × 0.06 × 0.06 mm |
Z = 2 |
Bruker APEXII CCD diffractometer | 3017 independent reflections |
Radiation source: fine-focus sealed tube | 2439 reflections with I > 2σ(I) |
Graphite monochromator | Rint = 0.030 |
ω scans | θmax = 28.3°, θmin = 2.9° |
Absorption correction: multi-scan (SADABS; Bruker, 2007) | h = −10→10 |
Tmin = 0.930, Tmax = 0.947 | k = −22→21 |
11795 measured reflections | l = −12→12 |
Refinement on F2 | Primary atom site location: structure-invariant direct methods |
Least-squares matrix: full | Secondary atom site location: difference Fourier map |
R[F2 > 2σ(F2)] = 0.032 | Hydrogen site location: inferred from neighbouring sites |
wR(F2) = 0.098 | H-atom parameters constrained |
S = 1.05 | w = 1/[σ2(Fo2) + (0.0554P)2 + 0.2257P] where P = (Fo2 + 2Fc2)/3 |
3017 reflections | (Δ/σ)max = 0.001 |
146 parameters | Δρmax = 0.24 e Å−3 |
0 restraints | Δρmin = −0.21 e Å−3 |
[Cu(C4H5O2)2(C8H11N)2] | V = 1217.73 (7) Å3 |
Mr = 476.06 | Z = 2 |
Monoclinic, P21/n | Mo Kα radiation |
a = 8.2295 (2) Å | µ = 0.93 mm−1 |
b = 17.0921 (6) Å | T = 296 K |
c = 9.1683 (3) Å | 0.08 × 0.06 × 0.06 mm |
β = 109.220 (1)° |
Bruker APEXII CCD diffractometer | 3017 independent reflections |
Absorption correction: multi-scan (SADABS; Bruker, 2007) | 2439 reflections with I > 2σ(I) |
Tmin = 0.930, Tmax = 0.947 | Rint = 0.030 |
11795 measured reflections |
R[F2 > 2σ(F2)] = 0.032 | 0 restraints |
wR(F2) = 0.098 | H-atom parameters constrained |
S = 1.05 | Δρmax = 0.24 e Å−3 |
3017 reflections | Δρmin = −0.21 e Å−3 |
146 parameters |
Geometry. All esds (except the esd in the dihedral angle between two l.s. planes) are estimated using the full covariance matrix. The cell esds are taken into account individually in the estimation of esds in distances, angles and torsion angles; correlations between esds in cell parameters are only used when they are defined by crystal symmetry. An approximate (isotropic) treatment of cell esds is used for estimating esds 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 > 2sigma(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 | ||
Cu1 | 0.5000 | 0.5000 | 0.5000 | 0.03574 (11) | |
N1 | 0.66520 (18) | 0.59275 (8) | 0.54344 (15) | 0.0370 (3) | |
C1 | 0.6584 (2) | 0.64975 (10) | 0.64342 (19) | 0.0418 (4) | |
C2 | 0.7823 (2) | 0.70758 (11) | 0.6865 (2) | 0.0468 (4) | |
H2 | 0.7740 | 0.7465 | 0.7546 | 0.056* | |
C5 | 0.7941 (2) | 0.59402 (10) | 0.48251 (18) | 0.0381 (3) | |
C9 | 0.2632 (2) | 0.57402 (11) | 0.2626 (2) | 0.0437 (4) | |
C3 | 0.9184 (2) | 0.70825 (11) | 0.6297 (2) | 0.0481 (4) | |
C8 | 0.7956 (2) | 0.53238 (12) | 0.3681 (2) | 0.0473 (4) | |
H8A | 0.7929 | 0.4817 | 0.4124 | 0.071* | |
H8B | 0.8984 | 0.5372 | 0.3410 | 0.071* | |
H8C | 0.6967 | 0.5385 | 0.2772 | 0.071* | |
C4 | 0.9208 (2) | 0.65059 (11) | 0.5248 (2) | 0.0456 (4) | |
H4 | 1.0089 | 0.6499 | 0.4821 | 0.055* | |
C6 | 0.5137 (3) | 0.64778 (13) | 0.7083 (3) | 0.0599 (5) | |
H6A | 0.4061 | 0.6456 | 0.6253 | 0.090* | |
H6B | 0.5173 | 0.6940 | 0.7686 | 0.090* | |
H6C | 0.5250 | 0.6024 | 0.7725 | 0.090* | |
C10 | 0.1618 (3) | 0.59108 (12) | 0.0974 (2) | 0.0568 (5) | |
C7 | 1.0593 (3) | 0.76821 (15) | 0.6826 (4) | 0.0776 (7) | |
H7A | 1.0113 | 0.8174 | 0.6986 | 0.116* | |
H7B | 1.1137 | 0.7743 | 0.6053 | 0.116* | |
H7C | 1.1429 | 0.7513 | 0.7776 | 0.116* | |
C11 | −0.0020 (4) | 0.62688 (19) | 0.0676 (4) | 0.0899 (9) | |
H11A | −0.0557 | 0.6336 | −0.0418 | 0.135* | |
H11B | 0.0123 | 0.6770 | 0.1175 | 0.135* | |
H11C | −0.0730 | 0.5942 | 0.1069 | 0.135* | |
C12 | 0.2280 (5) | 0.57196 (18) | −0.0179 (3) | 0.0934 (9) | |
H12A | 0.1650 | 0.5824 | −0.1205 | 0.112* | |
H12B | 0.3358 | 0.5486 | 0.0070 | 0.112* | |
O1 | 0.2181 (2) | 0.60068 (11) | 0.36686 (17) | 0.0675 (4) | |
O2 | 0.39586 (16) | 0.53088 (9) | 0.28566 (14) | 0.0477 (3) |
U11 | U22 | U33 | U12 | U13 | U23 | |
Cu1 | 0.03618 (17) | 0.03855 (17) | 0.03315 (16) | 0.00306 (11) | 0.01229 (11) | −0.00093 (11) |
N1 | 0.0376 (7) | 0.0391 (7) | 0.0338 (7) | 0.0041 (6) | 0.0111 (5) | −0.0006 (5) |
C1 | 0.0445 (9) | 0.0422 (9) | 0.0369 (8) | 0.0073 (7) | 0.0111 (7) | −0.0017 (7) |
C2 | 0.0508 (10) | 0.0402 (9) | 0.0429 (9) | 0.0065 (8) | 0.0067 (8) | −0.0061 (7) |
C5 | 0.0382 (8) | 0.0397 (8) | 0.0357 (8) | 0.0064 (7) | 0.0110 (6) | 0.0032 (6) |
C9 | 0.0429 (9) | 0.0445 (9) | 0.0413 (9) | −0.0048 (7) | 0.0105 (7) | 0.0056 (7) |
C3 | 0.0410 (9) | 0.0397 (9) | 0.0554 (10) | 0.0020 (7) | 0.0048 (8) | 0.0008 (8) |
C8 | 0.0463 (10) | 0.0512 (10) | 0.0501 (10) | 0.0021 (8) | 0.0234 (8) | −0.0064 (9) |
C4 | 0.0385 (9) | 0.0440 (9) | 0.0541 (10) | 0.0036 (7) | 0.0148 (8) | 0.0042 (8) |
C6 | 0.0649 (12) | 0.0605 (12) | 0.0639 (12) | 0.0007 (10) | 0.0341 (10) | −0.0178 (10) |
C10 | 0.0626 (12) | 0.0492 (11) | 0.0448 (10) | −0.0087 (9) | −0.0011 (9) | 0.0090 (8) |
C7 | 0.0593 (14) | 0.0602 (14) | 0.105 (2) | −0.0122 (11) | 0.0164 (13) | −0.0197 (14) |
C11 | 0.0769 (17) | 0.089 (2) | 0.0811 (18) | 0.0016 (15) | −0.0048 (13) | 0.0307 (16) |
C12 | 0.131 (2) | 0.101 (2) | 0.0391 (11) | 0.0127 (19) | 0.0155 (13) | −0.0022 (13) |
O1 | 0.0591 (9) | 0.0941 (12) | 0.0519 (8) | 0.0208 (8) | 0.0218 (7) | 0.0076 (8) |
O2 | 0.0486 (7) | 0.0534 (7) | 0.0385 (6) | 0.0038 (6) | 0.0109 (5) | 0.0035 (6) |
Cu1—O2 | 1.9406 (12) | C8—H8A | 0.9600 |
Cu1—O2i | 1.9406 (12) | C8—H8B | 0.9600 |
Cu1—N1i | 2.0404 (14) | C8—H8C | 0.9600 |
Cu1—N1 | 2.0404 (14) | C4—H4 | 0.9300 |
N1—C1 | 1.352 (2) | C6—H6A | 0.9600 |
N1—C5 | 1.352 (2) | C6—H6B | 0.9600 |
C1—C2 | 1.381 (3) | C6—H6C | 0.9600 |
C1—C6 | 1.496 (3) | C10—C12 | 1.378 (4) |
C2—C3 | 1.382 (3) | C10—C11 | 1.422 (4) |
C2—H2 | 0.9300 | C7—H7A | 0.9600 |
C5—C4 | 1.381 (3) | C7—H7B | 0.9600 |
C5—C8 | 1.490 (2) | C7—H7C | 0.9600 |
C9—O1 | 1.222 (2) | C11—H11A | 0.9600 |
C9—O2 | 1.276 (2) | C11—H11B | 0.9600 |
C9—C10 | 1.498 (3) | C11—H11C | 0.9600 |
C3—C4 | 1.382 (3) | C12—H12A | 0.9300 |
C3—C7 | 1.503 (3) | C12—H12B | 0.9300 |
O2—Cu1—O2i | 180.0 | H8B—C8—H8C | 109.5 |
O2—Cu1—N1i | 88.27 (6) | C5—C4—C3 | 120.81 (17) |
O2i—Cu1—N1i | 91.73 (6) | C5—C4—H4 | 119.6 |
O2—Cu1—N1 | 91.73 (6) | C3—C4—H4 | 119.6 |
O2i—Cu1—N1 | 88.27 (6) | C1—C6—H6A | 109.5 |
N1i—Cu1—N1 | 180.0 | C1—C6—H6B | 109.5 |
C1—N1—C5 | 118.81 (15) | H6A—C6—H6B | 109.5 |
C1—N1—Cu1 | 121.25 (11) | C1—C6—H6C | 109.5 |
C5—N1—Cu1 | 119.66 (11) | H6A—C6—H6C | 109.5 |
N1—C1—C2 | 121.22 (16) | H6B—C6—H6C | 109.5 |
N1—C1—C6 | 118.00 (16) | C12—C10—C11 | 122.9 (2) |
C2—C1—C6 | 120.77 (16) | C12—C10—C9 | 120.0 (2) |
C1—C2—C3 | 120.78 (17) | C11—C10—C9 | 117.1 (2) |
C1—C2—H2 | 119.6 | C3—C7—H7A | 109.5 |
C3—C2—H2 | 119.6 | C3—C7—H7B | 109.5 |
N1—C5—C4 | 121.21 (15) | H7A—C7—H7B | 109.5 |
N1—C5—C8 | 117.99 (15) | C3—C7—H7C | 109.5 |
C4—C5—C8 | 120.81 (15) | H7A—C7—H7C | 109.5 |
O1—C9—O2 | 123.32 (17) | H7B—C7—H7C | 109.5 |
O1—C9—C10 | 120.46 (18) | C10—C11—H11A | 109.5 |
O2—C9—C10 | 116.23 (17) | C10—C11—H11B | 109.5 |
C4—C3—C2 | 117.10 (17) | H11A—C11—H11B | 109.5 |
C4—C3—C7 | 121.63 (19) | C10—C11—H11C | 109.5 |
C2—C3—C7 | 121.26 (19) | H11A—C11—H11C | 109.5 |
C5—C8—H8A | 109.5 | H11B—C11—H11C | 109.5 |
C5—C8—H8B | 109.5 | C10—C12—H12A | 120.0 |
H8A—C8—H8B | 109.5 | C10—C12—H12B | 120.0 |
C5—C8—H8C | 109.5 | H12A—C12—H12B | 120.0 |
H8A—C8—H8C | 109.5 | C9—O2—Cu1 | 113.19 (11) |
O2—Cu1—N1—C1 | 115.81 (13) | C1—C2—C3—C4 | 2.3 (3) |
O2i—Cu1—N1—C1 | −64.19 (13) | C1—C2—C3—C7 | −176.5 (2) |
O2—Cu1—N1—C5 | −70.31 (12) | N1—C5—C4—C3 | −0.7 (3) |
O2i—Cu1—N1—C5 | 109.69 (12) | C8—C5—C4—C3 | 179.34 (17) |
C5—N1—C1—C2 | −1.6 (2) | C2—C3—C4—C5 | −1.5 (3) |
Cu1—N1—C1—C2 | 172.38 (13) | C7—C3—C4—C5 | 177.2 (2) |
C5—N1—C1—C6 | 179.36 (16) | O1—C9—C10—C12 | 169.3 (2) |
Cu1—N1—C1—C6 | −6.7 (2) | O2—C9—C10—C12 | −10.8 (3) |
N1—C1—C2—C3 | −0.7 (3) | O1—C9—C10—C11 | −10.9 (3) |
C6—C1—C2—C3 | 178.31 (18) | O2—C9—C10—C11 | 169.0 (2) |
C1—N1—C5—C4 | 2.3 (2) | O1—C9—O2—Cu1 | 8.1 (2) |
Cu1—N1—C5—C4 | −171.75 (12) | C10—C9—O2—Cu1 | −171.85 (13) |
C1—N1—C5—C8 | −177.78 (16) | N1i—Cu1—O2—C9 | 86.87 (13) |
Cu1—N1—C5—C8 | 8.2 (2) | N1—Cu1—O2—C9 | −93.13 (13) |
Symmetry code: (i) −x+1, −y+1, −z+1. |
D—H···A | D—H | H···A | D···A | D—H···A |
C4—H4···O1ii | 0.93 | 2.45 | 3.338 (2) | 161 |
C6—H6A···O1 | 0.96 | 2.49 | 3.369 (3) | 153 |
C6—H6C···O2i | 0.96 | 2.48 | 3.139 (3) | 126 |
C8—H8A···O1i | 0.96 | 2.49 | 3.357 (3) | 150 |
C8—H8C···O2 | 0.96 | 2.51 | 3.124 (2) | 122 |
Symmetry codes: (i) −x+1, −y+1, −z+1; (ii) x+1, y, z. |
Experimental details
Crystal data | |
Chemical formula | [Cu(C4H5O2)2(C8H11N)2] |
Mr | 476.06 |
Crystal system, space group | Monoclinic, P21/n |
Temperature (K) | 296 |
a, b, c (Å) | 8.2295 (2), 17.0921 (6), 9.1683 (3) |
β (°) | 109.220 (1) |
V (Å3) | 1217.73 (7) |
Z | 2 |
Radiation type | Mo Kα |
µ (mm−1) | 0.93 |
Crystal size (mm) | 0.08 × 0.06 × 0.06 |
Data collection | |
Diffractometer | Bruker APEXII CCD |
Absorption correction | Multi-scan (SADABS; Bruker, 2007) |
Tmin, Tmax | 0.930, 0.947 |
No. of measured, independent and observed [I > 2σ(I)] reflections | 11795, 3017, 2439 |
Rint | 0.030 |
(sin θ/λ)max (Å−1) | 0.667 |
Refinement | |
R[F2 > 2σ(F2)], wR(F2), S | 0.032, 0.098, 1.05 |
No. of reflections | 3017 |
No. of parameters | 146 |
H-atom treatment | H-atom parameters constrained |
Δρmax, Δρmin (e Å−3) | 0.24, −0.21 |
Computer programs: APEX2 (Bruker, 2007), SAINT (Bruker, 2007), SHELXS97 (Sheldrick, 2008), SHELXL97 (Sheldrick, 2008), ORTEP-3 (Farrugia, 1997).
D—H···A | D—H | H···A | D···A | D—H···A |
C4—H4···O1i | 0.93 | 2.45 | 3.338 (2) | 161 |
C6—H6A···O1 | 0.96 | 2.49 | 3.369 (3) | 153 |
C6—H6C···O2ii | 0.96 | 2.48 | 3.139 (3) | 126 |
C8—H8A···O1ii | 0.96 | 2.49 | 3.357 (3) | 150 |
C8—H8C···O2 | 0.96 | 2.51 | 3.124 (2) | 122 |
Symmetry codes: (i) x+1, y, z; (ii) −x+1, −y+1, −z+1. |
Acknowledgements
IUK thanks the Higher Education Commission of Pakistan for its financial support under the project to strengthen the Materials Chemistry Laboratory at GCUL.
References
Borel, M. M., Busnot, A., Busnot, F., Leclaire, A. & Bernard, M. A. (1981). Rev. Chem. Mineral. 18, 74–82. CAS Google Scholar
Bruker (2007). APEX2, SAINT and SADABS. Bruker AXS Inc., Madison, Wisconsin, USA. Google Scholar
Farrugia, L. J. (1997). J. Appl. Cryst. 30, 565. CrossRef IUCr Journals Google Scholar
Heimer, N. E. & Ahmed, I. V. (1982). Inorg. Chim. Acta, 65, L65–L66. CSD CrossRef Web of Science Google Scholar
Jedrzejas, M. J., Towns, R. L. R., Baker, R. J., Duraj, S. A. & Hepp, A. F. (1994). Acta Cryst. C50, 1442–1443. CSD CrossRef CAS Web of Science IUCr Journals Google Scholar
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The title compound, (I), is a centrosymmetric neutral monomeric copper(II) complex (Fig. 1). Related structures containing a copper(II) ion bonded to a pair of susbtituted pyridine ligands and a pair of monodentate carboxylate anions have been described previously (Borel et al., 1981; Heimer & Ahmed, 1982; Jedrzejas et al., 1994).
The Cu ion in (I) lies on an inversion centre, resulting in a slightly distorted trans-CuN2O2 square planar geometry for the metal ion (Table 1). If a very long contact between Cu1 and O1 [2.8229 (17)Å] is considered to have any significance as a bond, a grossly disorted trans-CuN2O4 octahedron results. The mean planes of the pyridine ring (r.m.s. deviation = 0.0099Å) and the carboxylate group (r.m.s. deviation = 0.0003Å) are roughly perpendicular [dihedral angle = 74.71 (7)°], which presumably minimises steric interactions between the ligands. The dihedral angles between the planar CuN2O2 core and the py ring and carboxylate plane are are 67.72 (5) and 89.95 (5)°, respectively. The Cu ion is displaced by 0.256 (3)Å from the py ring plane and by 0.252 (3)Å from the carboxylate plane. The carboxylate C—O bond lengths of 1.222 (2)Å for O1 and 1.276 (2)Å for O2 suggest the presence of relatively localised single and double bonds in the anion.
The terminal CH2 and CH3 groups of the carboxylate anion are probably disordered: the nominal C10—C11 single bond is short [1.422 (4)Å] and the nominal C10=C12 double bond is long [1.378 (4)Å]. This may also correlate with the Hirshfeld rigid bond alert for the C10—C12 bond. The presumed disorder could not be resolved in the present experiment. Several intramolecular C—H···O interactions occur (Table 1). In the crystal, the molecules are linked by C—H···O hydrogen bonds to generate chains in the [100] direction.
In trans-bis(acetato-O)bis(4-methyl pyridine-N)copper(II) (Jedrzejas et al., 1994), (II), the dihedral angle between the ligands is 78.2° (s.u. not stated), and the dihedral angle between the py ring and the CuN2O2 plane is 31.6°. The uncoordinated Cu···O separation of 2.623 (4)Å in (II) is significantly shorter than that seen in (I). However, it is notable that the carboxylate C—O bonds lengths in (II) [1.227 (7) and 1.279 (6)Å] are almost identical to those seen here.