Tetranuclear Metal Chelates of Nickel(II) with 1,2,5,6-Tetraphenyl-3,4-diaza-1,6-dihydroxyimino-2, 4-hexadiene.

Abstract

Tetrameric clusters of 1,2,5,6-tetraphenyl-3,4-diaza- 1,6-di-
hydroxyimino-2,4-hexadiene with Ni(II) of the type
Ni₄L₂X₄.12 H₂O (X = CI^-, Br^-, I^- or NO₃^- ) have been synthesised.
Vibrational and electronic spectra suggest co-ordination of the ligand
with the metal ions through nitrogen and oxygen atoms and each
central ion is present in a tetragonal ligand field with chromophores
NiN₄X₂ and each terminal nickel ion is present in an approxi, mately
octahedral ligand field with the chromophores NiO₆.