Complexes of zinc(II) with 1,2-disubstituted benzimidazoles

Abstract

The reactions of hydrated halides and perchlorate of divalent zinc with 1-o-hydroxybenzyl-2-o-hydroxyphenylbenzimidazole (L1), 1-m-hydroxybenzyl-2-m-hydroxyphenylbenzimidazole (L2), 1-p-hydroxybenzyl-2-p-hydroxyphenylbenzimidazole (L3) and 1-o-chlorobenzyl-2-o-chlorophenylbenzimidazole (L4) ligands in 1:2 and 1:3 molar ratios in absolute ethanol/acetone at refluxing temperature produced white/pale yellow complexes of the formula ZnX2L n. yH2O [L=L1, X = Cl, n = 2, y = 1; X = Br, n = 2, y = 0; X = l, n = 3, y = 1; X = ClO4, n = 2, y = 0; L = L 2, X = Cl, Br, n = 2, y = 1, X = ClO4, n = 2, y = 2; L = L3, X = Cl, n = 2, y = 0; X = Br, l, n = 3, y = 2; X = ClO 4, n = 2, y = 1; L = L4, X = Cl, n = 3, y = 2; X = Br, n = 3, y = 5; X = ClO4, n = 2, y = 0 ]. The complexes are characterised by elemental analysis, conductivity, thermal analysis, lR, 1H and 13C NMR spectral studies.