Metallogands: Part lll-Studies on some homo/hetero trinuclear nickel(II), cobalt(ll) and copper(ll) complexes of 4,5,8,9-tetraza-1,3,10,12-tetramethyl• 1,12-dioxo-6,7-diphenyl-1,3,5,7,9,11-dodecahexene

Abstract

A series of homo/hetero trinuclear complexes of the type [M Ni M (TTDD)₂X₂ (H₂O)_n] where M =nickel(II), cobalt(II) and copper(II), X =CI^-, Br^- and NO<img src='/image/spc_char/3_bar.gif' border=0>, n = 0 or 4 and TTDD = 4,5,8,9-tetraza- 1,3,10,12-tetramethyl-1, 12-dioxo-6,7-diphenyl-1,3,5,7,9,11- dodecahexene have been prepared in a stepwise reaction from the precursor Ni(II) bis-(benzil-dihydrazone) complexes and are characterised by elemental analyses, IR, UV/vis spectra, magnetic moments, molar conductances and thermal analyses. An approximately octahedral geometry around the metal(II) ions is proposed for all the complexes except Ni-Ni-Ni system where square planar geometry is proposed for the terminal metal(II) ions. Different ligand field parameters and the tetragonal splitting parameters have been estimated. The complexes containing Cu(II) ions have been screened against some fungal pathogens as possible fungicides.