Crystal Structure of a Bis[1-(benzothiazole-2yl-2κN)(2-Pyridylmethyliden-1κN)(hydrazino-2κN)] Cobalt(II) Complex

Abstract

The Schiff base 1-(benzothiazol-2-yl)(2-pyridylmethylidene)hydrazine (HL) was synthesis via a condensation of 1-(benzo[d]thiazol-2-yl)hydrazine and 2-pyridine carboxaldehyde in methanol in 1:1 molar ratio reaction. The crystal structure of a mononuclear complex Bis[1-(benzothiazole-2yl-2κN)(2-pyridylmethyliden-1κN)(hydrazino-2κN)] cobalt(II) complex (1) (CoC26H20N8S2) was obtained by the reaction of HL with Co(CH3COO)2.4H2O, in 2:1 ratio, in methanol at room temperature. The ligand and the complex are characterized by IR, and physical measurement. The spectroscopic study shows that the Schiff base possesses five potential donor sites. Upon coordination the results show that the ligand acts in tridentate mode. Suitable crystals of the compound 1 were grown by slow evaporation of methanol solution for one week. The structure of 1 was elucidated by X-ray diffraction analysis. The compound crystallizes in the monoclinic crystal system with a space group of P21/c. The asymmetric unit of compound 1 contains a mononuclear complex in which the cobalt ion is coordinated to two monodeprotonated molecules of the Schiff base. Each of the ligand molecule acts through three nitrogen atoms. The Co(II) center is hexacoordinated and the environment is best described as a distorted octahedral geometry. The two ligand molecules occupy mean planes which are quasi-perpendicular with a dihedral angle of 89.77(2)°. Each molecule of complex is connected to its neighbor via hydrogen bond of type C–H•••S resulting in chains along b axis.