catena-Poly[[[2-(1,3-thiazol-4-yl)-1H-benzimidazole]manganese(II)]-μ-oxalato]

In the title compound, [Mn(C2O4)(C10H7N3S)]n, the MnII cation is chelated by one 2-(1,3-thiazol-4-yl)-1H-benzimidazole ligand and two oxalate anions in a distorted N2O4 octahedral geometry. Two independent oxalate anions are located on individual inversion centers and bridge the MnII cations into a polymeric chain running along [101]. The thiazole ring is approximately coplanar with the benzimidazole ring system [dihedral angle = 4.19 (9)°]. In the crystal, classical N—H⋯O hydrogen bonds and weak C—H⋯O hydrogen bonds link the polymeric chains into a three-dimensional supramolecular architecture.

In the title compound, [Mn(C 2 O 4 )(C 10 H 7 N 3 S)] n , the Mn II cation is chelated by one 2-(1,3-thiazol-4-yl)-1H-benzimidazole ligand and two oxalate anions in a distorted N 2 O 4 octahedral geometry. Two independent oxalate anions are located on individual inversion centers and bridge the Mn II cations into a polymeric chain running along [101]. The thiazole ring is approximately coplanar with the benzimidazole ring system [dihedral angle = 4.19 (9) ]. In the crystal, classical N-HÁ Á ÁO hydrogen bonds and weak C-HÁ Á ÁO hydrogen bonds link the polymeric chains into a threedimensional supramolecular architecture.

Comment
Thiabendazole aroused considerable interest in biology and medicine due to its antiproliferative activities. It is an antimicrobial drug belonging to the benzimidazole derivative, and has exhibited wide applications in human and veterinary medicine (Jean et al., 2002;Devereux et al., 2004).
As part of our studies of the synthesis and characterization of these compounds, we report here the synthesis and crystal structure of [Mn(C 2 O 4 )(thiabendazole)] n . In this work, the structure of the complex is formed by infinite one-dimensional chains. Each Mn(II) center is six-coordinated by two N-atoms (N1, N2) and four O-atoms (O1, O2, O3, O4) of the carboxylate from two H 2 C 2 O 4 ligands and two N-atoms from a chelated tbz ligand (Fig. 1). The dihedral angle between the least squares calculated planes through the adjacent tbz (benzene ring) ligand is close to 90 °. The Mn-O bond lengths of 2.164-2.215 Å are shorter than the the Zn-N bond length of 2.228-2.317 Å, where Jahn-Teller effects have not been observed. The complex form a one-dimensional chain structure by bis(bidentate) bridging H 2 C 2 O 4 , and thiabendazole located on both sides of the chain (Fig. 2). The complex is stabilized by hydrogen bonds formed by N3-H3···O1 hydrogen bonds from N-H of tbz together with oxygen atoms of [C 2 O 4 ] 2ligands, their length is 1.962 Å and within the normal range. Because the direction of the hydrogen bonds is not the same, the hydrogen bonds interlink the 1-D chains to generate three-dimensional supramolecular architectures ( Fig. 3) (Wisniewski et al., 2001;Yu et al., 2002).

Experimental
A solution of thiabendazole (0.2023 g, 1 mmol) in 5 ml DMF was added dropwise with stirring at room temperature to a solution of Mn(Cl) 2 .4H 2 O (0.1976 g, 1 mmol), H 2 C 2 O 4 (0.0411 g, 0.5 mmol) in the mixture of 12.5 ml water and 5 ml methanol. Then an aqueous solution of sodium hydroxide was added dropwise with stirring to adjust the pH value of the solution being 6.5. The resulting mixture was sealed in a 25 mL Teflon-lined stainless reactor, kept under autogenous pressure at 423 K for 72 h, and then slowly cooled to room temperature at a rate of 10 K per hour. The colorless block crystals suitable for X-ray diffraction were isolated directly, washed with ethanol and dried in air (0.

Refinement
H atoms were positioned geometrically and refined as riding atoms with C-H = 0.93 and N-H = 0.86 Å, U iso (H) = 1.2U eq (C,N).

Figure 1
The asymmetric unit of the title compound. Displacement ellipsoids are drawn at the 30% probability level.

Figure 2
Perspective view of the chains in the title compound.  Crystal packing of the title compound. Dashed lines denote hydrogen bonds.

catena-Poly[[[2-(1,3-thiazol-4-yl)-1H-benzimidazole]manganese(II)]-µ-oxalato]
Crystal data Hydrogen site location: inferred from neighbouring sites H-atom parameters constrained w = 1/[σ 2 (F o 2 ) + (0.0339P) 2 + 0.5684P] where P = (F o 2 + 2F c 2 )/3 (Δ/σ) max = 0.001 Δρ max = 0.27 e Å −3 Δρ min = −0.28 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 F 2 against ALL reflections. The weighted R-factor wR and goodness of fit S are based on F 2 , conventional R-factors R are based on F, with F set to zero for negative F 2 . The threshold expression of F 2 > σ(F 2 ) is used only for calculating R-factors(gt) etc. and is not relevant to the choice of reflections for refinement. R-factors based on F 2 are statistically about twice as large as those based on F, and R-factors based on ALL data will be even larger.