Monochelates and bischelates of nickel(II) with bis-benzimidazolyl derivatives

Abstract

The reaction of the hydrated halides/perchlorate of nickel(II) with bis-benzimidazolyl derivatives (I), namely, 1,3-bis(benzimidazol-2-yl) benzene(bbzlH₂bzH; L¹),1,3-bis(1-methylbenzimidazol-2-yl)benzene (bbzlMe₂bzH; L²) and 2,6-bis(1-methylbenzimidazol-2-yl)pyridine (bbzlMe₂py; L³) in stoichiometric amounts in absolute ethanol-teof and acetone has afforded a series of nickel(II) complexes with the formulae NiX₂L.nH₂O (X = Cl or Br, L = L¹ or L², n = 2; X = I, L = L², n= 1; X = Cl, Br or I, L = L³ n = 0), NiI₂L¹H₂O.(CH₃)₂CO and Ni(L)₂(ClO₄)₂.nH₂O (L = L¹ or L², n = 0; L = L³ , n = 2. The brown iodo complex, NiI₂L³ turns green on exposure to atmosphere, giving NiI₂L³.2H₂O. The complexes have been

characterised by elemental analyses, conductivity and magnetic measurement s, infrared and electronic spectral studies as well as thermal analysis.