Synthesis, spectral studies of copper(II)tetrathiocyanato dithallate(I) complexes with some acylhydrazones and their antimicrobial activity

Abstract

Heterobimetallic complexes of Cu[Tl(SCN)₂]₂ ·; L (where L = acetophenone benzoylhydrazone(abh), acetophenone isonicotinoyl hydrazone(ainh), acetophenone salicyloylhydrazone(ash), acetophenone anthraniloyl hydrazone(aah), p-hydroxy acetophenone benzoylhydrazone (phabh), p-hydroxy acetophenone isonicotinoyl hydrazone (phainh), p-hydroxy acetophenone salicyloylhydrazone(phash) and p-hydroxy acetophenone anthraniloyl hydrazone(phaah) were synthesized and characterized. Electronic spectra and μ_eff values suggest a distorted octahedral environment around copper(II). SCN groups bridge between two metal centers and the ligands are coordinated through >C=O and >C=N–groups. Thermal studies (TGA and DTA) on Cu[Tl(SCN)₂]₂ · ainh indicate multi step decomposition of both endothermic and exothermic nature. ESR data show axial spectra for all the complexes and d _{x² − y ²} as the ground state. Powder X-ray diffraction parameters for some of the complexes correspond to orthorhombic crystal lattice. The complexes show significant antifungal activity against Rizoctonia sp. and Stemphylium sp. and moderate antibacterial activity against Clostridium sp. and Pseudomonas sp. The activity increases at higher concentration of the compound.

Keywords:

• Copper(II)
• Thallium(I) thiocyanate complexes
• Acylhydrazones
• Antifungal
• Antibacterial activity
• Characterization

Acknowledgements

The authors thank the Director, Institute of Engineering and Technology, C.S.J.M. University Kanpur for providing laboratory facilities, the Head, Chemistry Department, Indian Institute and Technology, Kanpur for recording electronic, IR, ESR spectra, thermal and X-ray diffraction studies. The authors also thank to Dr Nand Lal, Institute of Life Sciences, CSJM University, Kanpur for his help in antimicrobial screening.