Bis{μ-2-[bis­(pyridin-2-yl)methyl­idene]hydrazinecarbothio­amidato}bis­[bromido­copper(II)] methanol disolvate

Roji J Kunnath; M Sithambaresan; M R Prathapachandra Kurup; Aiswarya Natarajan; A Ambili Aravindakshan

doi:10.1107/S1600536812005934

. 2012 Feb 29;68(Pt 3):m346–m347. doi: 10.1107/S1600536812005934

Bis{μ-2-[bis(pyridin-2-yl)methylidene]hydrazinecarbothioamidato}bis[bromidocopper(II)] methanol disolvate

Roji J Kunnath ^a, M Sithambaresan ^b,^*, M R Prathapachandra Kurup ^a, Aiswarya Natarajan ^a, A Ambili Aravindakshan ^a

PMCID: PMC3297285 PMID: 22412475

Abstract

In the centrosymmetric binuclear title compound, [Cu₂Br₂(C₁₂H₁₀N₅S)₂]·2CH₃OH, the Cu^II ion adopts a slightly distorted square-pyramidal coordination geometry. The hydrazine carbothioamide moiety and one of the pyridyl rings together adopt an almost planar arrangement, with a maximum deviation of 0.052 (4) Å for the C atom of the thiourea moiety. There are two molecules of methanol solvent per complex in the asymmetric unit. The nonconventional intramolecular C—H⋯Br hydrogen bonds make the molecule more rigid, whereas the conventional N—H⋯N and O—H⋯Br intermolecular hydrogen-bonding interactions, supported with N—H⋯π interactions, establish a supramolecular linkage among the molecules in the crystal. An intermolecular C—H⋯O interaction is also present.

Related literature

For the biological applications of multinuclear copper complexes of hydrazinecarbothioamide, see: Moubaraki et al. (1998 ▶); Khan et al. (1985 ▶). For the synthesis of the title compound, see: Philip et al. (2006 ▶). For related structures of dimeric copper complexes of hydrazinecarbothioamide, see: Ainscough et al. (1991 ▶); Philip et al. (2005 ▶). For related literature, see: Duan et al. (1996 ▶).

Experimental

Crystal data

[Cu₂Br₂(C₁₂H₁₀N₅S)₂]·2CH₄O
M _r = 863.62
Triclinic,
a = 8.3052 (7) Å
b = 9.2120 (7) Å
c = 11.0500 (9) Å
α = 68.341 (2)°
β = 79.127 (3)°
γ = 84.913 (2)°
V = 771.45 (11) Å³
Z = 1
Mo Kα radiation
μ = 4.15 mm⁻¹
T = 296 K
0.30 × 0.25 × 0.25 mm

Data collection

Bruker AXS Kappa APEXII CCD diffractometer
Absorption correction: multi-scan (SADABS; Bruker, 2004 ▶) T _min = 0.300, T _max = 0.354
11266 measured reflections
2688 independent reflections
2374 reflections with I > 2σ(I)
R _int = 0.065

Refinement

R[F ² > 2σ(F ²)] = 0.034
wR(F ²) = 0.094
S = 1.08
2688 reflections
209 parameters
2 restraints
H atoms treated by a mixture of independent and constrained refinement
Δρ_max = 0.46 e Å⁻³
Δρ_min = −0.48 e Å⁻³

Data collection: APEX2 (Bruker, 2004 ▶); cell refinement: APEX2/SAINT (Bruker, 2004 ▶); data reduction: SAINT/XPREP (Bruker, 2004 ▶); program(s) used to solve structure: SHELXS97 (Sheldrick, 2008 ▶); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008 ▶); molecular graphics: ORTEP-3 (Farrugia, 1997 ▶) and DIAMOND (Brandenburg, 2010 ▶); software used to prepare material for publication: SHELXL97 and publCIF (Westrip, 2010 ▶).

Supplementary Material

Crystal structure: contains datablock(s) global, I. DOI: 10.1107/S1600536812005934/fj2511sup1.cif

e-68-0m346-sup1.cif^{(23.7KB, cif)}

Structure factors: contains datablock(s) I. DOI: 10.1107/S1600536812005934/fj2511Isup2.hkl

e-68-0m346-Isup2.hkl^{(132KB, hkl)}

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

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

Cg4 is the centroid of the N2/C7–C11 ring.

D—H⋯A	D—H	H⋯A	D⋯A	D—H⋯A
O1—H1A⋯Br1ⁱ	0.82	2.58	3.396 (4)	178
N5—H5A⋯N4ⁱⁱ	0.84 (2)	2.17 (2)	3.006 (4)	177 (5)
C4—H4⋯O1ⁱⁱⁱ	0.93	2.44	3.281 (5)	151
C11—H11⋯Br1^iv	0.93	2.86	3.573 (4)	135
C1—H1⋯Br1	0.93	2.91	3.450 (4)	119
N5—H5B⋯Cg4ⁱⁱ	0.84 (2)	2.71 (4)	3.310 (4)	129 (3)

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

Acknowledgments

RJK is grateful to University Grants Commision, New Delhi, India, for the award of a Senior Research Fellowship. AN and AAA are grateful to the Council of Scientific and Industrial Research, New Delhi, India, for financial support in the form of Junior Research Fellowships. The authors are grateful to the Sophisticated Analytical Instument Facility, Cochin University of Science and Technology, Kochi-22, for providing single-crystal X-ray diffraction data.

supplementary crystallographic information

Comment

Hydrazinecarbothioamides have been reported to have a great variety of biological activity. In most cases, the metal complexes show more activity compared to their metal free ligands (Moubaraki et al., 1998). Coupled systems of transition metal complexes are of special interest in various fields of science. The main reason probably is due to the phenomenon of interaction between metal centers lying at the crossover point of two widely separated areas, namely the physics of the magnetic materials and the role of polynuclear reaction sites in biological processes (Khan et al., 1985).

The title complex [Cu₂Br₂(C₁₂H₁₀N₅S)₂].2(CH₃OH) has a dimeric structure. The coordination geometry around each copper(II) ion is square pyramidal with a slight distortion (τ = 0.03). The S1 atom of the hydrazinecarbothioamide moiety, the imino N3 atom, pyridine N1 atom and the Br1 atom comprise the basal plane while the apical position is occupied by the N2A atom of the symmetry related half of the dimer with a longest bond length to the metal atom of 2.529 (3) Å. The hydrazinecarbothioamide moiety of the free ligand shows E configuration about the both C12–N4 and C6–N3 (Ainscough et al., 1991; Philip et al., 2005) whereas in the Cu^II complex the coordinated hydrazinecarbothioamide moiety has E configuration with respect to C6–N3 and Z configuration about C12–N4. The atoms coordinated to metal centre found to exist in E configuration having N3 and N1 atoms cis to each other with respect to C5—C6 bond. A unique part of the Cu^II complex and the dimeric unit generated by the association of the free pyridyl nitrogen with the Cu atom are shown along with the atom-labeling in Fig. 1 and 2 respectively. The two aromatic rings are twisted with a dihedral angle of 88.1 (2)° between the rings. The hydrazinecarbothioamide moiety and one of the pyridine ring comprising atoms C1—C6 and N1 are almost planar with maximum deviation of 0.052 (4) Å for the atom C12 of the ring. C12–S1 bond distance (1.727 (4) Å) is very close to the single bond (Duan et al., 1996) which suggests that the ligand is coordinated in the thiolate form. This phenomenon could also be further confirmed by the coplanar nature of the NH₂ group of the coordinated ligand with sp² character wich facilitates an extended conjugation of the hydrazinecarbothioamide moiety with the aromatic rings.

The intramolecular non-classical hydrogen bonding interactions (C1–H1···Br1 and C11–H11···Br1), Table 1, makes the complex more rigid. The intermolecular hydrogen bonding interactions (classical and non-classical) establish a supramolecular 1-D network by linking the adjacent molecules through the methanol present in the lattice and N—H···N in parallel fashion as shown in Fig. 3. Packing of the molecules also involves many very weak π..π interactions with centroid-centroid distances in the range 3.707 (2)–5.778 (2). However, there is an N—H···π interaction between the hydrogen attached at N5 atom and one of the pyridyl ring comprising atoms from C7—C11 and N2 of another molecule and also a lone-pair···π interaction between the Br1 atom and two different chelate rings comprising atoms Cu1, S1, C12, N3, N4 and Cu1, N1, N3, C5, C6.

Experimental

The title complex was prepared by adapting a reported procedure (Philip et al., 2006) by refluxing a mixture of methanolic solutions of 2-[di(pyridin-2-yl)methylidene]hydrazinecarbothioamide (2.573 g, 10 mmol) and CuBr₂ (2.230 g, 10 mmol) for four hours. Black colored crystals were collected, washed with few drops of methanol and dried over P₄O₁₀in vacuo. Single crystals of the title complex suitable for X-ray analysis were obtained by slow evaporation from its methanolic solution.