Tetra­kis(μ-2-methyl­benzoato)bis­[(2-methyl­benzoic acid)copper(II)]

Sunil, A.C.; Bezuidenhoudt, B.C.B.; Janse van Rensburg, J.M.

doi:10.1107/S1600536808006661

metal-organic compounds

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ISSN: 2056-9890

Volume 64| Part 4| April 2008| Pages m553-m554

doi:10.1107/S1600536808006661

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Tetrakis(μ-2-methylbenzoato)bis[(2-methylbenzoic acid)copper(II)]

Abraham C. Sunil,^a Barend C. B. Bezuidenhoudt ^a ^* and J. Marthinus Janse van Rensburg ^a

^aDepartment of Chemistry, University of the Free State, PO Box 339, Bloemfontein 9300, South Africa
^*Correspondence e-mail: bezuidbc.sci@ufs.ac.za

(Received 22 February 2008; accepted 10 March 2008; online 14 March 2008)

In the title centrosymmetric dinuclear compound, [Cu₂(C₈H₇O₂)₄(C₈H₈O₂)₂], four o-toluate anions form a cage around two Cu atoms in a syn–syn configuration. Two more o-toluic acid molecules are apically bonded to the Cu atoms, which show a square-pyramidal coordination geometry. The acid H atoms are hydrogen bonded to the cage carboxyl O atoms [O⋯O = 2.660 (2) Å]. The molecular packing forms a puckered pseudo-hexagonal close-packed layer in the (h00) plane, with soft intermolecular H⋯H contacts (2.46–2.58 Å).

Related literature

For the synthesis of aromatic carboxylic acids, see: Kaeding (1967 ). For tetrakis(μ₂-2-fluorobenzoato)bis(2-fluorobenzoic acid)dicopper(II), see: Valach et al. (2000 ), For tetrakis(μ₂-benzoato)bis(2-fluorobenzoic acid)dicopper(II), see: Kawata et al. (1992 ).

Experimental

Crystal data

[Cu₂(C₈H₇O₂)₄(C₈H₈O₂)₂]
M_r = 939.96
Triclinic, $[P \overline 1]$
a = 10.530 (3) Å
b = 10.579 (3) Å
c = 10.773 (4) Å
α = 109.248 (2)°
β = 93.156 (2)°
γ = 106.287 (2)°
V = 1073.0 (6) Å³
Z = 1
Mo Kα radiation
μ = 1.06 mm⁻¹
T = 100 (2) K
0.25 × 0.08 × 0.06 mm

Data collection

Bruker X8 APEXII diffractometer
Absorption correction: multi-scan (SADABS; Bruker, 2004 b) T_min = 0.778, T_max = 0.939
17497 measured reflections
5138 independent reflections
4668 reflections with I > 2σ(I)
R_int = 0.025

Refinement

R[F² > 2σ(F²)] = 0.026
wR(F²) = 0.065
S = 1.05
5138 reflections
284 parameters
H-atom parameters constrained
Δρ_max = 0.41 e Å⁻³
Δρ_min = −0.33 e Å⁻³

Table 1
Selected bond lengths (Å)

Cu1—O21ⁱ	1.9402 (12)
Cu1—O11	1.9559 (12)
Cu1—O12	1.9585 (13)
Cu1—O22ⁱ	1.9900 (13)
Cu1—O31	2.1622 (13)
Cu1⋯Cu1ⁱ	2.5780 (9)
Symmetry code: (i) -x+1, -y+1, -z+1.

Table 2
Hydrogen-bond geometry (Å, °)

D—H⋯A	D—H	H⋯A	D⋯A	D—H⋯A
O32—H32⋯O22ⁱ	0.82	1.85	2.6604 (18)	168
C16—H16⋯O21	0.93	2.39	2.721 (2)	101
Symmetry code: (i) -x+1, -y+1, -z+1.

Data collection: APEX2 (Bruker, 2005 ); cell refinement: SAINT-Plus (Bruker, 2004); data reduction: SAINT-Plus and XPREP (Bruker, 2004); program(s) used to solve structure: SIR97 (Altomare et al., 1999 ); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008 ); molecular graphics: DIAMOND (Brandenburg & Putz, 2005 ); software used to prepare material for publication: WinGX (Farrugia, 1999 ).

Supporting information

Crystal structure: contains datablocks global, I. DOI: 10.1107/S1600536808006661/ng2426sup1.cif

Structure factors: contains datablock I. DOI: 10.1107/S1600536808006661/ng2426Isup2.hkl

checkCIF report

Comment top

In our endeavours to produce phenols from aromatic carboxylic acids, we came across work by Kaeding (1967). In order to verify the reaction sequence as proposed by Kaeding, we prepared the copper salt of o-toluic acid and obtained single crystals.

The title compound, (I), [Cu₂(C₈H₇O₂)₄(C₈H₈O₂)₂] crystallized with molecular symmetry -1 (Fig.1). The title compound exhibits a cage-like structure. Four o-toluic anionic ligands form a cage around two Cu-atoms in a syn-syn configuration. Two more carboxylic acid are apically bonded to the Cu-atoms. The acid protons are hydrogen bonded to the cage carboxylate O atoms, O32—H32···O22 = 167.6° and O32···O22 = 2.6604 (18) Å. Another intra-molecular H···H short contact is present at C16···O21 with C16—H16···O21 = 100.9° and C16···O21 = 2.721 (2) Å.

Comparing the Van der Waals radii of copper, 2.32 Å, and the metallic Cu—Cu bond length, 2.55 Å, to the Cu—Cu separation in (I), 2.5780 (9) Å, one would expect the presence of weak orbital interaction. The Cu—O bond lengths of the cage carboxylates vary between 1.9402 (12) - 1.9900 (13) Å. The Cu—O bond distances to the adducted acid molecules show a ca 0.2 Å increase. Each Cu atom is displaced from the basal plane of the four caged carboxylates by 0.171 Å, towards the apical O atom. Compound (I) forms a puckered pseudo-hexagonal close packed layer in the (h 0 0) plane, with soft inter-molecular H···H contacts, 2.457–2.580 Å (Fig.2).

Related literature top

For the synthesis of aromatic carboxylic acids, see: Kaeding (1967). For tetrakis(µ₂-2-fluorobenzoato)-bis(2-fluorobenzoic acid)-di-copper(II), see: Valach et al. (2000), For tetrakis(µ₂benzoato)-bis(2-fluorobenzoic acid)-di-copper(II), see: Kawata et al. (1992).

Experimental top

The complex [Cu₂(C₈H₇O₂)₄(C₈H₈O₂)₂] was prepared by heating o-toluic acid (2.52 g, 18.5 mmol), copper carbonate (0.73 g, 3.3 mmol) and magnesium oxide (0.19 g, 4.68 mmol) under reflux, in toluene (30 ml) for 24 h. The product was extacted and crystallized from diethyl ether to yield a blue crystalline solid. (Yield: 84%)

Computing details top

Data collection: APEX2 (Bruker, 2005); cell refinement: SAINT-Plus (Bruker, 2004); data reduction: SAINT-Plus and XPREP (Bruker, 2004); program(s) used to solve structure: SIR97 (Altomare et al., 1999); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008); molecular graphics: DIAMOND (Brandenburg & Putz, 2005); software used to prepare material for publication: WinGX (Farrugia, 1999).

Figures top

	Fig. 1. A view of (I) showing the atom-numbering scheme with displacement ellipsoids at the 30% probability level, non labelled atoms are symmetric equivalents. For the phenyl C-atoms, the first digit indicates ring number and the second digit the position of the atom in the ring.
	Fig. 2. Indication of pseudo-hexagonal close packing along the b axis.

Tetrakis(µ-2-methylbenzoato)bis[(2-methylbenzoic acid)copper(II)] top

Crystal data top

[Cu₂(C₈H₇O₂)₄(C₈H₈O₂)₂]	Z = 1
M_r = 939.96	F(000) = 486
Triclinic, P1	D_x = 1.455 Mg m⁻³
Hall symbol: -P 1	Mo Kα radiation, λ = 0.71069 Å
a = 10.530 (3) Å	Cell parameters from 8974 reflections
b = 10.579 (3) Å	θ = 2.6–28.3°
c = 10.773 (4) Å	µ = 1.06 mm⁻¹
α = 109.248 (2)°	T = 100 K
β = 93.156 (2)°	Needle, blue
γ = 106.287 (2)°	0.25 × 0.08 × 0.06 mm
V = 1073.0 (6) Å³

Data collection top

Bruker X8 APEXII 4K KappaCCD diffractometer	5138 independent reflections
Radiation source: fine-focus sealed tube	4668 reflections with I > 2σ(I)
Graphite monochromator	R_int = 0.026
ω and ϕ scans	θ_max = 28°, θ_min = 2.2°
Absorption correction: multi-scan (SADABS; Bruker, 2004b)	h = −13→13
T_min = 0.778, T_max = 0.939	k = −13→13
17497 measured reflections	l = −14→14

Refinement top

Refinement on F²	0 restraints
Least-squares matrix: full	H-atom parameters constrained
R[F² > 2σ(F²)] = 0.026	w = 1/[σ²(F_o²) + (0.024P)² + 0.7431P] where P = (F_o² + 2F_c²)/3
wR(F²) = 0.065	(Δ/σ)_max = 0.001
S = 1.05	Δρ_max = 0.41 e Å⁻³
5138 reflections	Δρ_min = −0.33 e Å⁻³
284 parameters

Crystal data top

[Cu₂(C₈H₇O₂)₄(C₈H₈O₂)₂]	γ = 106.287 (2)°
M_r = 939.96	V = 1073.0 (6) Å³
Triclinic, P1	Z = 1
a = 10.530 (3) Å	Mo Kα radiation
b = 10.579 (3) Å	µ = 1.06 mm⁻¹
c = 10.773 (4) Å	T = 100 K
α = 109.248 (2)°	0.25 × 0.08 × 0.06 mm
β = 93.156 (2)°

Data collection top

Bruker X8 APEXII 4K KappaCCD diffractometer	5138 independent reflections
Absorption correction: multi-scan (SADABS; Bruker, 2004b)	4668 reflections with I > 2σ(I)
T_min = 0.778, T_max = 0.939	R_int = 0.026
17497 measured reflections

Refinement top

R[F² > 2σ(F²)] = 0.026	0 restraints
wR(F²) = 0.065	H-atom parameters constrained
S = 1.05	Δρ_max = 0.41 e Å⁻³
5138 reflections	Δρ_min = −0.33 e Å⁻³
284 parameters

Special details top

Experimental. The intensity data was collected on a Bruker X8 Apex II 4 K Kappa CCD diffractometer using an exposure time of 30 s/frame. The 1757 frames were collected with a frame width of 0.5° covering up to θ = 28° with 99.3% completeness accomplished.

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.

Fractional atomic coordinates and isotropic or equivalent isotropic displacement parameters (Å²) top

	x	y	z	U_iso*/U_eq
Cu1	0.444832 (17)	0.389154 (17)	0.395103 (17)	0.01027 (6)
O32	0.51055 (11)	0.07974 (12)	0.26534 (12)	0.0217 (2)
H32	0.5525	0.1594	0.3175	0.033*
O31	0.36065 (11)	0.18596 (11)	0.23619 (10)	0.0154 (2)
O21	0.47477 (11)	0.50089 (11)	0.70973 (10)	0.0175 (2)
O22	0.38457 (10)	0.65099 (11)	0.57571 (11)	0.0168 (2)
O11	0.38005 (11)	0.30802 (11)	0.52758 (10)	0.0157 (2)
O12	0.29312 (10)	0.46128 (11)	0.39073 (10)	0.0150 (2)
C16	0.36586 (15)	0.36861 (16)	0.87485 (15)	0.0161 (3)
H16	0.3999	0.4666	0.9049	0.019*
C31	0.31192 (15)	−0.05882 (15)	0.11267 (14)	0.0142 (3)
C11	0.35899 (14)	0.29021 (15)	0.74017 (14)	0.0126 (3)
C36	0.37677 (17)	−0.14773 (16)	0.03537 (16)	0.0189 (3)
H36	0.4698	−0.1226	0.0517	0.023*
C25	0.00903 (16)	0.72093 (17)	0.56202 (18)	0.0235 (3)
H25	−0.0326	0.7479	0.6358	0.028*
C321	0.09555 (16)	−0.00753 (18)	0.17572 (17)	0.0229 (3)
H32A	0.0954	0.0674	0.1443	0.034*
H32B	0.138	0.0318	0.2672	0.034*
H32C	0.0049	−0.065	0.1684	0.034*
C1	0.40786 (14)	0.37152 (15)	0.65233 (14)	0.0127 (3)
C12	0.30930 (15)	0.14154 (15)	0.69355 (15)	0.0143 (3)
C15	0.32315 (16)	0.30349 (17)	0.96407 (16)	0.0183 (3)
H15	0.3285	0.3569	1.0533	0.022*
C2	0.29274 (14)	0.57566 (15)	0.47500 (14)	0.0119 (3)
C13	0.26600 (15)	0.07881 (16)	0.78583 (16)	0.0166 (3)
H13	0.2318	−0.0191	0.7571	0.02*
C32	0.17142 (16)	−0.09665 (16)	0.09292 (15)	0.0168 (3)
C21	0.17807 (14)	0.62904 (14)	0.45946 (15)	0.0131 (3)
C33	0.10027 (17)	−0.22517 (17)	−0.00704 (16)	0.0229 (3)
H33	0.0071	−0.2536	−0.0213	0.027*
C22	0.13237 (16)	0.63473 (16)	0.33772 (16)	0.0182 (3)
C121	0.30291 (18)	0.04573 (16)	0.55228 (16)	0.0211 (3)
H12A	0.278	−0.0505	0.5475	0.032*
H12B	0.3892	0.0707	0.5256	0.032*
H12C	0.2375	0.0561	0.4939	0.032*
C26	0.11778 (16)	0.67358 (16)	0.57076 (16)	0.0175 (3)
H26	0.151	0.6714	0.6516	0.021*
C34	0.16490 (19)	−0.31154 (17)	−0.08566 (16)	0.0254 (4)
H34	0.1149	−0.396	−0.1525	0.03*
C3	0.39545 (15)	0.08020 (15)	0.21105 (14)	0.0137 (3)
C35	0.30350 (19)	−0.27297 (17)	−0.06539 (16)	0.0238 (4)
H35	0.3469	−0.3305	−0.1189	0.029*
C14	0.27235 (15)	0.15762 (17)	0.91873 (16)	0.0177 (3)
H14	0.2425	0.1125	0.9775	0.021*
C24	−0.03711 (16)	0.72774 (17)	0.44262 (19)	0.0261 (4)
H24	−0.11	0.7598	0.436	0.031*
C221	0.1966 (2)	0.5912 (2)	0.21626 (17)	0.0314 (4)
H22A	0.2917	0.6378	0.2388	0.047*
H22B	0.1603	0.6173	0.1481	0.047*
H22C	0.1789	0.4909	0.1842	0.047*
C23	0.02467 (17)	0.68697 (17)	0.33293 (18)	0.0250 (4)
H23	−0.0062	0.6945	0.2539	0.03*

Atomic displacement parameters (Å²) top

	U¹¹	U²²	U³³	U¹²	U¹³	U²³
Cu1	0.01089 (9)	0.00896 (9)	0.01017 (9)	0.00293 (6)	0.00121 (6)	0.00270 (6)
O32	0.0162 (5)	0.0158 (5)	0.0258 (6)	0.0068 (4)	−0.0053 (5)	−0.0019 (5)
O31	0.0165 (5)	0.0124 (5)	0.0150 (5)	0.0054 (4)	−0.0001 (4)	0.0019 (4)
O21	0.0211 (6)	0.0135 (5)	0.0143 (5)	0.0004 (4)	0.0038 (4)	0.0047 (4)
O22	0.0126 (5)	0.0159 (5)	0.0178 (5)	0.0056 (4)	−0.0018 (4)	0.0006 (4)
O11	0.0205 (5)	0.0135 (5)	0.0122 (5)	0.0031 (4)	0.0019 (4)	0.0053 (4)
O12	0.0145 (5)	0.0132 (5)	0.0157 (5)	0.0058 (4)	−0.0003 (4)	0.0025 (4)
C16	0.0170 (7)	0.0144 (7)	0.0160 (7)	0.0042 (6)	0.0020 (6)	0.0052 (6)
C31	0.0177 (7)	0.0117 (6)	0.0126 (7)	0.0041 (6)	0.0018 (6)	0.0043 (5)
C11	0.0099 (6)	0.0153 (7)	0.0139 (7)	0.0045 (5)	0.0023 (5)	0.0066 (6)
C36	0.0235 (8)	0.0156 (7)	0.0187 (8)	0.0083 (6)	0.0057 (6)	0.0057 (6)
C25	0.0163 (8)	0.0180 (8)	0.0319 (9)	0.0058 (6)	0.0088 (7)	0.0026 (7)
C321	0.0146 (7)	0.0262 (8)	0.0265 (9)	0.0060 (6)	0.0035 (6)	0.0082 (7)
C1	0.0115 (7)	0.0141 (7)	0.0142 (7)	0.0061 (5)	0.0027 (5)	0.0055 (5)
C12	0.0121 (7)	0.0154 (7)	0.0158 (7)	0.0048 (6)	0.0011 (5)	0.0057 (6)
C15	0.0197 (8)	0.0227 (8)	0.0139 (7)	0.0081 (6)	0.0042 (6)	0.0067 (6)
C2	0.0121 (7)	0.0116 (6)	0.0131 (7)	0.0026 (5)	0.0035 (5)	0.0066 (5)
C13	0.0134 (7)	0.0149 (7)	0.0216 (8)	0.0028 (6)	0.0021 (6)	0.0083 (6)
C32	0.0190 (7)	0.0156 (7)	0.0152 (7)	0.0028 (6)	0.0008 (6)	0.0073 (6)
C21	0.0109 (6)	0.0093 (6)	0.0169 (7)	0.0015 (5)	0.0013 (5)	0.0038 (5)
C33	0.0232 (8)	0.0182 (8)	0.0211 (8)	−0.0025 (6)	−0.0041 (7)	0.0082 (6)
C22	0.0196 (8)	0.0158 (7)	0.0181 (8)	0.0072 (6)	−0.0005 (6)	0.0038 (6)
C121	0.0297 (9)	0.0130 (7)	0.0189 (8)	0.0054 (6)	0.0039 (7)	0.0048 (6)
C26	0.0165 (7)	0.0151 (7)	0.0191 (7)	0.0040 (6)	0.0038 (6)	0.0044 (6)
C34	0.0394 (10)	0.0137 (7)	0.0149 (8)	−0.0004 (7)	−0.0029 (7)	0.0034 (6)
C3	0.0138 (7)	0.0146 (7)	0.0120 (7)	0.0041 (6)	0.0036 (5)	0.0043 (5)
C35	0.0401 (10)	0.0146 (7)	0.0167 (8)	0.0110 (7)	0.0069 (7)	0.0034 (6)
C14	0.0147 (7)	0.0242 (8)	0.0194 (8)	0.0063 (6)	0.0046 (6)	0.0141 (6)
C24	0.0141 (7)	0.0183 (8)	0.0399 (10)	0.0076 (6)	−0.0033 (7)	0.0022 (7)
C221	0.0442 (11)	0.0427 (11)	0.0175 (8)	0.0258 (9)	0.0062 (8)	0.0134 (8)
C23	0.0246 (9)	0.0205 (8)	0.0264 (9)	0.0094 (7)	−0.0085 (7)	0.0041 (7)

Geometric parameters (Å, º) top

Cu1—O21ⁱ	1.9402 (12)	C321—H32B	0.96
Cu1—O11	1.9559 (12)	C321—H32C	0.96
Cu1—O12	1.9585 (13)	C12—C13	1.397 (2)
Cu1—O22ⁱ	1.9900 (13)	C12—C121	1.510 (2)
Cu1—O31	2.1622 (13)	C15—C14	1.385 (2)
Cu1—Cu1ⁱ	2.5780 (9)	C15—H15	0.93
O32—C3	1.3184 (19)	C2—C21	1.492 (2)
O32—H32	0.82	C13—C14	1.386 (2)
O31—C3	1.2250 (18)	C13—H13	0.93
O21—C1	1.2670 (18)	C32—C33	1.394 (2)
O21—Cu1ⁱ	1.9402 (12)	C21—C26	1.394 (2)
O22—C2	1.2764 (18)	C21—C22	1.398 (2)
O22—Cu1ⁱ	1.9900 (13)	C33—C34	1.385 (3)
O11—C1	1.2626 (18)	C33—H33	0.93
O12—C2	1.2518 (18)	C22—C23	1.399 (2)
C16—C15	1.382 (2)	C22—C221	1.502 (2)
C16—C11	1.400 (2)	C121—H12A	0.96
C16—H16	0.93	C121—H12B	0.96
C31—C36	1.397 (2)	C121—H12C	0.96
C31—C32	1.404 (2)	C26—H26	0.93
C31—C3	1.485 (2)	C34—C35	1.384 (3)
C11—C12	1.410 (2)	C34—H34	0.93
C11—C1	1.497 (2)	C35—H35	0.93
C36—C35	1.384 (2)	C14—H14	0.93
C36—H36	0.93	C24—C23	1.383 (3)
C25—C24	1.381 (3)	C24—H24	0.93
C25—C26	1.383 (2)	C221—H22A	0.96
C25—H25	0.93	C221—H22B	0.96
C321—C32	1.506 (2)	C221—H22C	0.96
C321—H32A	0.96	C23—H23	0.93

O21ⁱ—Cu1—O11	170.01 (4)	O12—C2—O22	124.23 (14)
O21ⁱ—Cu1—O12	87.99 (5)	O12—C2—C21	118.96 (13)
O11—Cu1—O12	91.79 (5)	O22—C2—C21	116.81 (13)
O21ⁱ—Cu1—O22ⁱ	89.93 (5)	C14—C13—C12	122.17 (14)
O11—Cu1—O22ⁱ	88.55 (5)	C14—C13—H13	118.9
O12—Cu1—O22ⁱ	169.88 (4)	C12—C13—H13	118.9
O21ⁱ—Cu1—O31	98.74 (6)	C33—C32—C31	117.35 (15)
O11—Cu1—O31	91.16 (6)	C33—C32—C321	119.26 (15)
O12—Cu1—O31	99.14 (5)	C31—C32—C321	123.37 (14)
O22ⁱ—Cu1—O31	90.97 (5)	C26—C21—C22	120.83 (14)
O21ⁱ—Cu1—Cu1ⁱ	87.75 (5)	C26—C21—C2	117.76 (13)
O11—Cu1—Cu1ⁱ	82.27 (5)	C22—C21—C2	121.41 (13)
O12—Cu1—Cu1ⁱ	86.61 (4)	C34—C33—C32	121.67 (16)
O22ⁱ—Cu1—Cu1ⁱ	83.41 (4)	C34—C33—H33	119.2
O31—Cu1—Cu1ⁱ	171.44 (3)	C32—C33—H33	119.2
C3—O32—H32	109.5	C21—C22—C23	117.30 (15)
C3—O31—Cu1	129.50 (10)	C21—C22—C221	122.57 (15)
C1—O21—Cu1ⁱ	119.83 (10)	C23—C22—C221	120.12 (15)
C2—O22—Cu1ⁱ	123.41 (10)	C12—C121—H12A	109.5
C1—O11—Cu1	125.45 (10)	C12—C121—H12B	109.5
C2—O12—Cu1	122.02 (10)	H12A—C121—H12B	109.5
C15—C16—C11	121.39 (14)	C12—C121—H12C	109.5
C15—C16—H16	119.3	H12A—C121—H12C	109.5
C11—C16—H16	119.3	H12B—C121—H12C	109.5
C36—C31—C32	120.86 (14)	C25—C26—C21	120.55 (15)
C36—C31—C3	118.27 (14)	C25—C26—H26	119.7
C32—C31—C3	120.78 (13)	C21—C26—H26	119.7
C16—C11—C12	119.90 (13)	C35—C34—C33	120.44 (15)
C16—C11—C1	116.94 (13)	C35—C34—H34	119.8
C12—C11—C1	123.16 (13)	C33—C34—H34	119.8
C35—C36—C31	120.42 (16)	O31—C3—O32	123.59 (13)
C35—C36—H36	119.8	O31—C3—C31	122.29 (14)
C31—C36—H36	119.8	O32—C3—C31	114.10 (13)
C24—C25—C26	119.35 (16)	C36—C35—C34	119.22 (16)
C24—C25—H25	120.3	C36—C35—H35	120.4
C26—C25—H25	120.3	C34—C35—H35	120.4
C32—C321—H32A	109.5	C15—C14—C13	120.05 (14)
C32—C321—H32B	109.5	C15—C14—H14	120
H32A—C321—H32B	109.5	C13—C14—H14	120
C32—C321—H32C	109.5	C25—C24—C23	120.20 (16)
H32A—C321—H32C	109.5	C25—C24—H24	119.9
H32B—C321—H32C	109.5	C23—C24—H24	119.9
O11—C1—O21	124.51 (13)	C22—C221—H22A	109.5
O11—C1—C11	118.61 (13)	C22—C221—H22B	109.5
O21—C1—C11	116.88 (13)	H22A—C221—H22B	109.5
C13—C12—C11	117.39 (14)	C22—C221—H22C	109.5
C13—C12—C121	117.89 (14)	H22A—C221—H22C	109.5
C11—C12—C121	124.70 (13)	H22B—C221—H22C	109.5
C16—C15—C14	119.09 (15)	C24—C23—C22	121.72 (16)
C16—C15—H15	120.5	C24—C23—H23	119.1
C14—C15—H15	120.5	C22—C23—H23	119.1

O21ⁱ—Cu1—O31—C3	108.89 (13)	C11—C12—C13—C14	−0.8 (2)
O11—Cu1—O31—C3	−69.75 (13)	C121—C12—C13—C14	177.70 (14)
O12—Cu1—O31—C3	−161.75 (13)	C36—C31—C32—C33	−0.5 (2)
O22ⁱ—Cu1—O31—C3	18.81 (13)	C3—C31—C32—C33	176.08 (14)
O12—Cu1—O11—C1	−88.41 (12)	C36—C31—C32—C321	178.06 (14)
O22ⁱ—Cu1—O11—C1	81.47 (12)	C3—C31—C32—C321	−5.4 (2)
O31—Cu1—O11—C1	172.41 (12)	O12—C2—C21—C26	131.59 (15)
Cu1ⁱ—Cu1—O11—C1	−2.08 (11)	O22—C2—C21—C26	−47.95 (19)
O21ⁱ—Cu1—O12—C2	−87.01 (12)	O12—C2—C21—C22	−48.5 (2)
O11—Cu1—O12—C2	83.00 (12)	O22—C2—C21—C22	131.91 (15)
O22ⁱ—Cu1—O12—C2	−8.8 (3)	C31—C32—C33—C34	−1.1 (2)
O31—Cu1—O12—C2	174.46 (11)	C321—C32—C33—C34	−179.70 (15)
Cu1ⁱ—Cu1—O12—C2	0.85 (11)	C26—C21—C22—C23	0.1 (2)
C15—C16—C11—C12	−0.8 (2)	C2—C21—C22—C23	−179.71 (14)
C15—C16—C11—C1	179.95 (14)	C26—C21—C22—C221	178.43 (16)
C32—C31—C36—C35	2.2 (2)	C2—C21—C22—C221	−1.4 (2)
C3—C31—C36—C35	−174.48 (14)	C24—C25—C26—C21	−1.9 (2)
Cu1—O11—C1—O21	5.1 (2)	C22—C21—C26—C25	1.7 (2)
Cu1—O11—C1—C11	−175.02 (9)	C2—C21—C26—C25	−178.42 (14)
Cu1ⁱ—O21—C1—O11	−5.4 (2)	C32—C33—C34—C35	1.0 (2)
Cu1ⁱ—O21—C1—C11	174.78 (9)	Cu1—O31—C3—O32	−13.1 (2)
C16—C11—C1—O11	−166.58 (13)	Cu1—O31—C3—C31	168.70 (10)
C12—C11—C1—O11	14.2 (2)	C36—C31—C3—O31	144.89 (15)
C16—C11—C1—O21	13.27 (19)	C32—C31—C3—O31	−31.8 (2)
C12—C11—C1—O21	−165.91 (14)	C36—C31—C3—O32	−33.43 (19)
C16—C11—C12—C13	1.3 (2)	C32—C31—C3—O32	149.91 (14)
C1—C11—C12—C13	−179.57 (13)	C31—C36—C35—C34	−2.2 (2)
C16—C11—C12—C121	−177.11 (14)	C33—C34—C35—C36	0.7 (2)
C1—C11—C12—C121	2.1 (2)	C16—C15—C14—C13	0.6 (2)
C11—C16—C15—C14	−0.1 (2)	C12—C13—C14—C15	−0.2 (2)
Cu1—O12—C2—O22	−5.0 (2)	C26—C25—C24—C23	0.3 (2)
Cu1—O12—C2—C21	175.52 (9)	C25—C24—C23—C22	1.6 (3)
Cu1ⁱ—O22—C2—O12	7.4 (2)	C21—C22—C23—C24	−1.8 (2)
Cu1ⁱ—O22—C2—C21	−173.12 (9)	C221—C22—C23—C24	179.87 (17)

Symmetry code: (i) −x+1, −y+1, −z+1.

Hydrogen-bond geometry (Å, º) top

D—H···A	D—H	H···A	D···A	D—H···A
O32—H32···O22ⁱ	0.82	1.85	2.6604 (18)	168
C16—H16···O21	0.93	2.39	2.721 (2)	101

Symmetry code: (i) −x+1, −y+1, −z+1.

Experimental details

Crystal data
Chemical formula	[Cu₂(C₈H₇O₂)₄(C₈H₈O₂)₂]
M_r	939.96
Crystal system, space group	Triclinic, P1
Temperature (K)	100
a, b, c (Å)	10.530 (3), 10.579 (3), 10.773 (4)
α, β, γ (°)	109.248 (2), 93.156 (2), 106.287 (2)
V (Å³)	1073.0 (6)
Z	1
Radiation type	Mo Kα
µ (mm⁻¹)	1.06
Crystal size (mm)	0.25 × 0.08 × 0.06

Data collection
Diffractometer	Bruker X8 APEXII 4K KappaCCD diffractometer
Absorption correction	Multi-scan (SADABS; Bruker, 2004b)
T_min, T_max	0.778, 0.939
No. of measured, independent and observed [I > 2σ(I)] reflections	17497, 5138, 4668
R_int	0.026
(sin θ/λ)_max (Å⁻¹)	0.661

Refinement
R[F² > 2σ(F²)], wR(F²), S	0.026, 0.065, 1.05
No. of reflections	5138
No. of parameters	284
H-atom treatment	H-atom parameters constrained
Δρ_max, Δρ_min (e Å⁻³)	0.41, −0.33

Computer programs: APEX2 (Bruker, 2005), SAINT-Plus (Bruker, 2004), SAINT-Plus and XPREP (Bruker, 2004), SIR97 (Altomare et al., 1999), SHELXL97 (Sheldrick, 2008), DIAMOND (Brandenburg & Putz, 2005), WinGX (Farrugia, 1999).

Selected bond lengths (Å) top

Cu1—O21ⁱ	1.9402 (12)	Cu1—Cu1ⁱ	2.5780 (9)
Cu1—O11	1.9559 (12)	C31—C3	1.485 (2)
Cu1—O12	1.9585 (13)	C11—C1	1.497 (2)
Cu1—O22ⁱ	1.9900 (13)	C2—C21	1.492 (2)
Cu1—O31	2.1622 (13)

Symmetry code: (i) −x+1, −y+1, −z+1.

Hydrogen-bond geometry (Å, º) top

D—H···A	D—H	H···A	D···A	D—H···A
O32—H32···O22ⁱ	0.82	1.85	2.6604 (18)	167.6
C16—H16···O21	0.93	2.39	2.721 (2)	100.9

Symmetry code: (i) −x+1, −y+1, −z+1.

Acknowledgements

Financial assistance from the University of the Free State and SASOL to ACS is gratefully acknowledged. Opinions, findings, conclusions or recommendations expressed in this material are those of the authors and do not necessarily reflect the views of SASOL.

References

Altomare, A., Burla, M. C., Camalli, M., Cascarano, G. L., Giacovazzo, C., Guagliardi, A., Moliterni, A. G. G., Polidori, G. & Spagna, R. (1999). J. Appl. Cryst. 32, 115–119. Web of Science CrossRef CAS IUCr Journals Google Scholar
Brandenburg, K. & Putz, H. (2005). DIAMOND. Crystal Impact GbR, Bonn, Germany. Google Scholar
Bruker (2004). SAINT-Plus (including XPREP) and SADABS. Bruker AXS Inc., Madison, Wisconsin, USA. Google Scholar
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Kawata, T., Uekusa, H., Ohba, S., Furukawa, T., Tokii, T., Muto, Y. & Kato, M. (1992). Acta Cryst. B48, 253–261. CSD CrossRef CAS Web of Science IUCr Journals Google Scholar
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Valach, F., Tokarcik, M., Maris, T., Watkin, D. J. & Prout, C. K. (2000). Z. Kristallogr. 215, 56–60. CSD CrossRef CAS Google Scholar

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Volume 64| Part 4| April 2008| Pages m553-m554

doi:10.1107/S1600536808006661

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