Complexes of Nickel(II) and Cobalt(II) with Biacetyldihydrazone

Department of Chemistry, Indian Institute of Technology, Kharagpur-721302

Manuscript received 20 February 1976 ; accepted 27 April 1976

A number of biacetyldihydrazone metal complexes of the type, M(BDH)₂X₂ (where M=Ni(II), Co(II) ; X = Br^-, I^-, SCN^-, NO₃^-, BF₄^- and BDH=biacetyldihydrazone) have been isolated by metal ion catalysed template syntheses. The complexes possess characteristic colours and are non-hygros­copic, sparingly soluble in water and can be stored for a long period without decomposition. The infrared spectra show considerable metal to ligand π electron interactions which are manifested by the shift of the C=N bond stretching vibrations to a higher frequency region. The complexes are found to be spin free paramagnetic with nearly octahedral arrangement of the ligand atoms about the metal ions.