Transition metal complexes containing tridentate hydrazone Schiff bases Synthesis, characterization and biological activity

Department of Chemistry, Sant Gadge Baba Amravati University, Amravati-444 602, Maharashtra, India
E-mail : aswar2341@rediffmail.com
Manuscript received 23 March 2010, revised 06 September 2010, accepted 05 October 2010

The new mononuclear complexes of Ti^lll, Cr^lll, Mn^lll and Fe^lll with tridentate hydrazone ligands viz. 2-
hydroxy-5-chloroacetophenonebenzoylhydrazone (H₂L_¹) and 2-hydroxy-3,5-dichloroacetophenone-4-nitrobenzoylhydrazone
(H₂L²) have been synthesized and characterized by elemental analysis, FTIR, reflectance spectra, magnetic susceptibility
and thermogravimetric analyses (TG). From the analytical data, the stoichiometry of the complexes has been found
to be 1 : 1 (metal : organic ligand). The physicochemical data suggested octahedral geometry for all the complexes.
Electrical conductivity measurements of the complexes have been made over a wide range of temperatures and it was
found that complexes showed semiconducting behavior. Various kinetic parameters have been evaluated from thermal
decomposition data by both Horowitz-Metzger and Coats-Redfern methods and comparable values are obtained. The
ligands and their metal complexes were screened for their antibacterial activity against E. coli, S. abony, P. aeruginosa,
S. aureus and B. subtilis and fungicidal activity against A. niger and C. albicans.