Synthesis, spectral, biological, thermal and cyclic voltammetric studies of some NiII complexes of azodyes derived from 4-amino antipyrine

Department of Chemistry, University College, Thiruvananthapuram-635 034, India
Department of Chemistry, St. Gregorios College, Kottarakara-691 531, India
Manuscript received 21 June 2004, revised 11 April 2005, accepted 14 July 2005

Some new Ni^II complexes of the ligands 2,3-dimethyl-1-phenyl-4-(2-hydroxy-5-methyl phenyl azo)pyrazol-5-one (CAAPH) and 2,3-dimethyl-1-phenyl-4-(2-hydroxy-5-chloro phenyl azo)pyrazol-5-one (CPAAPH) having the compositions [Ni(LH)₂Cl₂], [Ni(LH)(Ac)₂], [Ni(LH)(NO₃)₂], [Ni(LH)SO₄], [Ni(LH)₂(ClO₄)]ClO₄, [Ni(LH)₂(NCS)CI], [Ni(L'H)₂CI₂], [Ni(L'H)(Ac)₂], [Ni(L'H)(NO₃)₂], [Ni(L'H)SO₄], (Ni(L'H)₂(ClO₄)]ClO₄ and [Ni(L'H)₂(NCS)CI] (LH = CAAPH and L'H = CPAAPH) have been synthesised and characterised by elemental analysis, IR, electronic and ¹H NMR spectra, magnetic and conductance measurements, thermal and cyclic voltammetric studies. The ligands and complexes have been screened for their antibacterial activity against gram positive and gram negative bacteria.