Synthesis, characterisation and antimicrobial activity of bis(phthalazine-1-hydrazone)-2,6-diacetylpyridine and its complexes with Co-III, Ni-II, Cu-II and Zn-II

Abstract

Four new complex compounds of bis(phthalazine-1-hydrazone)-2,6-diacetylpyridine (Hz(2)DAP) ligand with Ni-II, Co-III, Cu-II and Zn-II metal centres were synthesised and characterised by single-crystal X-ray diffraction and IR spectral data. The antimicrobial activity of Hz(2)DAP and the obtained complexes [Co(Hz(2)DAP-H)Cl-2]center dot MeOH, [Ni(Hz(2)DAP-H)]Cl center dot MeOH, [Cu(Hz(2)DAP-H)Cl] and [Zn(Hz(2)DAP-2H)]center dot H2O were tested in vitro against selected Gram(-) and Gram(+) bacterial strains and fungi. The antimicrobial activity of the ligand is negligible, while its complexes with Ni-II, Co-III and Cu-II show considerable activity against Escherichia coli, Staphylococcus aureus and Micrococcus lysodeikticus. On the contrary, [Zn(Hz(2)DAP-2H)]center dot H2O promotes the growth of Candida albicans, while its antibacterial activity is negligible. On the basis of thermal data and those from coupled TG/MS measurements the decomposition mechanisms were determined and evaluated. (C) 2014 Elsevier Ltd. All rights reserved.