Aqua­(2,2′-bipyridine-κ2 N,N′)(2-methyl­malonato-κ2 O 1,O 3)copper(II) dihydrate

P Manochitra; N Manikandan; S Murugavel; R Sreeshailam; P Sambasiva Rao

doi:10.1107/S1600536812024889

. 2012 Jun 13;68(Pt 7):m884–m885. doi: 10.1107/S1600536812024889

Aqua(2,2′-bipyridine-κ² N,N′)(2-methylmalonato-κ² O ¹,O ³)copper(II) dihydrate

P Manochitra ^a, N Manikandan ^b, S Murugavel ^c,^*, R Sreeshailam ^a, P Sambasiva Rao ^a

PMCID: PMC3393161 PMID: 22807729

Abstract

In the title compound, [Cu(C₄H₄O₄)(C₁₀H₈N₂)(H₂O)]·2H₂O, the Cu^II ion displays a slightly distorted square-pyramidal coordination. The water molecule at the apical position shows a long bond [Cu—O = 2.276 (2) Å]. The basal plane is formed by two N atoms of the 2,2′-bipyridine ligand and two carboxylate O atoms from a malonate group. The five-membered chelate ring is almost planar [maximum deviation = −0.006 (2) Å], while the six-membered chelate ring defined by the malonate ligand adopts a distorted boat conformation. In the crystal, Cu^II complex molecules and lattice water molecules are connected by O—H⋯O and C—H⋯O hydrogen bonds. The crystal packing is further stabilized by π–π interactions [centroid–centroid distances = 3.563 (2)–3.828 (2) Å].

Related literature

For background to the applications of copper(II)–malonate complexes, see: Braga et al. (1998 ▶); Suresh & Bhadbhade (1997 ▶). For related structures, see: Gasque et al. (1998 ▶); Cui et al. (2005 ▶). For ring puckering analysis, see: Cremer & Pople (1975 ▶).

Experimental

Crystal data

[Cu(C₄H₄O₄)(C₁₀H₈N₂)(H₂O)]·2H₂O
M _r = 389.84
Monoclinic,
a = 10.7588 (7) Å
b = 7.4761 (6) Å
c = 20.1029 (13) Å
β = 90.917 (6)°
V = 1616.7 (2) Å³
Z = 4
Mo Kα radiation
μ = 1.39 mm⁻¹
T = 293 K
0.25 × 0.23 × 0.17 mm

Data collection

Oxford Diffraction Xcalibur Eos diffractometer
Absorption correction: multi-scan (CrysAlis PRO; Oxford Diffraction, 2009 ▶) T _min = 0.699, T _max = 0.790
9120 measured reflections
3782 independent reflections
2771 reflections with I > 2σ(I)
R _int = 0.045

Refinement

R[F ² > 2σ(F ²)] = 0.049
wR(F ²) = 0.119
S = 1.05
3782 reflections
242 parameters
6 restraints
H atoms treated by a mixture of independent and constrained refinement
Δρ_max = 0.97 e Å⁻³
Δρ_min = −0.52 e Å⁻³

Data collection: CrysAlis CCD (Oxford Diffraction, 2009 ▶); cell refinement: CrysAlis RED (Oxford Diffraction, 2009 ▶); data reduction: CrysAlis RED; 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 and PLATON (Spek, 2009 ▶).

Supplementary Material

Crystal structure: contains datablock(s) global, I. DOI: 10.1107/S1600536812024889/bt5931sup1.cif

e-68-0m884-sup1.cif^{(27KB, cif)}

Structure factors: contains datablock(s) I. DOI: 10.1107/S1600536812024889/bt5931Isup2.hkl

e-68-0m884-Isup2.hkl^{(181.7KB, hkl)}

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

Table 1. Hydrogen-bond geometry (Å, °).

D—H⋯A	D—H	H⋯A	D⋯A	D—H⋯A
C4—H4⋯O3ⁱ	0.93	2.59	3.457 (4)	155
O3—H3A⋯O4ⁱⁱ	0.82 (3)	1.97 (4)	2.775 (3)	170 (3)
O3—H3B⋯O6ⁱⁱⁱ	0.85 (5)	1.90 (5)	2.744 (4)	173 (4)
O6—H6A⋯O5^iv	0.84 (2)	1.96 (2)	2.787 (3)	168 (4)
O6—H6B⋯O5^v	0.84 (1)	1.97 (1)	2.800 (4)	170 (4)
O7—H7A⋯O4^iv	0.83 (1)	2.12 (2)	2.907 (4)	158 (4)
O7—H7B⋯O6^vi	0.84 (1)	2.10 (1)	2.932 (5)	170 (4)
C2—H2⋯O7^vii	0.93	2.50	3.256 (5)	139
C12—H12⋯O4ⁱⁱ	0.98	2.47	3.300 (5)	142

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Symmetry codes: (i) Inline graphic ; (ii) ; (iii) ; (iv) ; (v) ; (vi) ; (vii) .

Acknowledgments

PM thanks Pondicherry University for a fellowship. The authors gratefully acknowledge the single-crystal XRD facility (DST-FIST), Department of Chemistry, Pondicherry University, for the XRD data.

supplementary crystallographic information

Comment

The copper(II)—malonate complexes with suitable N-heterocyclic auxiliary ligands are of interest because the metal-N-heterocyclic chelate ring could influence the Cu—O(carboxyl) bond lengths and exhibits some degree of 'metalloaromaticity' (Suresh & Bhadbhade, 1997). On the other hand, self-assembly processes involving metal ions and organic ligands has attracted increasing attention for the development of novel functional materials with desired properties (Braga et al., 1998). In continuation of the structural studies of metal complexes of these ligands, the crystal structure of the title compound was determined.

Fig. 1. shows a displacement ellipsoid plot of the title complex. The Cu^IIion displays a slightly distorted quadratic pyramidal geometry and is coordinated to two N atoms of a 2,2'-bipyridine ligand and two carboxylate O atoms from a malonate group in the basal plane, and to a water molecule in the apical position [Cu1–O3 = 2.276 (2) Å]. The Cu1^II ion is displaced by -0.2382 (4) Å from the basal plane (N1/N2/O1/O2) towards the apical position. The O3 atom of the water molecule coordinated in the apical position deviates from this basal plane by 2.514 (2) Å. A similar coordination behaviour is observed in a similar structure (Gasque et al., 1998), in which Cu1 deviates by 0.239 (2) Å and O3 atom by 2.533 (3) Å from the corresponding basal plane. The angle subtended by the pyridine ligand at the metal atom is far from the ideal value of 90° [81.0 (1)° for N1—Cu1—N2]. The bond distances Cu1—N1 = 2.004 (3), Cu1—N2 = 2.001 (1), Cu1—O1 = 1.907 (2) and Cu1—O2 = 1.919 (2) Å agree well with those reported for similar structures (Gasque et al., 1998; Cui et al., 2005).

The five-membered chelate ring (N1/N2/C5/C6/Cu1) is almost planar [maximum deviation = -0.006 (2) Å for atom N1], while the six-membered chelate ring defined by the malonate ligand (O1/O2/C11/C12/C13/Cu1) adopts a slightly distorted boat conformation as indicated by the puckering parameters (Cremer & Pople, 1975): Q = 0.580 (3) Å, θ = 81.8 (3)° and φ = 187.9 (3)°.

The crystal packing is stabilized by extensive intermolecular O—H···O and C—H···O hydrogen bonding interactions (Table 1) between the copper complex and uncordinated water molecules (Fig. 2). The crystal packing is further stabilized by π—π interactions with Cg1—Cg1^viii, Cg1—Cg3^viii, Cg3—Cg1^viii, Cg3—Cg4^viii, Cg4—Cg3^viii, Cg3—Cg4ⁱ and Cg4—Cg3ⁱ seperations of 3.563 (2), 3.828 (2), 3.828 (2), 3.805 (2), 3.805 (2) 3.720 (2) and 3.720 (2) Å (Cg1, Cg2, Cg3 and Cg4 are the centroids of Cu1/N1/N2/C5/C6 ring, Cu1/O1/O2/C11/C12/C13 ring, N1/C1–C5 pyridine ring and N2/C6–C10 pyridine ring, respectively, symmetry codes: (i) 1-x, 1-y, -z; (viii) 1-x, -y, -z).

Experimental

Basic copper(II) carbonate (1 mmol) was treated with an aqueous solution (10 ml) of methylmalonic acid (2 mmol) in a steam bath until the solid disappeared. The solution was then filtered and diluted to approximately 40 ml with water. An ethanol solution (10 ml) of 2,2'-bipyridine (2 mmol) was then added to above solution. The resultant clear-blue solution was warmed on a steam bath for 1 h. The volume was kept constant by periodic addition of water. Then the solution was filtered and allowed to stand at room temperature. Blue single crystals were obtained after 2 days. They were filtered, washed with water, ethanol and air dried.