Synthesis, crystal structure, and antibacterial activity of mononuclear nickel(II) and cobalt(III) Schiff-base complexes

Abstract

Four new mononuclear complexes, [Ni(L¹)(NCS)₂] (1), [Ni(L²)(NCS)₂] (2), [Co(L¹)(N₃)₂]ClO₄ (3), and [Co(L²)(N₃)₂]ClO₄ (4), where L¹ and L² are N,N′-bis[(pyridin-2-yl)methylidene]butane-1,4-diamine and N,N′-bis[(pyridin-2-yl)benzylidene]butane-1,4-diamine, respectively, have been prepared. The syntheses have been achieved by reaction of the respective metal perchlorate with the tetradentate Schiff bases, L¹ and L², in presence of thiocyanate (for 1 and 2) or azide (for 3 and 4). The complexes have been characterized by microanalytical, spectroscopic, single crystal X-ray diffraction and other physicochemical studies. Structural studies reveal that 1–4 are distorted octahedral geometries. The antibacterial activity of all the complexes and their constituent Schiff bases have been tested against Gram-positive and Gram-negative bacteria.

Keywords:

• Nickel(II)
• Cobalt(III)
• Schiff base
• Crystal structure
• Antibacterial activity

Acknowledgments

Our thanks are extended to Rt. Revd. Dr P.K. Dutta (Chairman of Governing Body), Dr R.N. Bajpai (Principal), and Dr S.K. Roy (Head, Chemistry Department) of Bankura Christian College for their constant encouragement and valuable suggestions in doing the work.