1,2-Bis-(2-benzimidazolyl)-1,2-ethanediol and 1,4-bis-(2-benzimidazolyl)-1,2,3,4-butanetetraol PdCl2 complexes

The 1,2-bis-(2-benzimidazolyl)-1,2-ethanediol (EH2) and 1,4-bis-(2-benzimid azolyl)-1,2,3,4-butanetetraol (TH4) ligands form 4-coordinate mono- and bi- metallic complexes with PdCl2, respectively. In Pd(EH2)Cl-2 the ligand acts as a bidentate through two of the nitrogen atoms. On the other hand, in Pd -2(TH4)Cl-4 the ligand coordinates to two palladium atoms through both bis- benzimidazole nitrogen atoms and two oxygen atoms of the hydroxy groups, fo rming two different isomers. The complexes were characterised by analytical data, magnetic susceptibility, molar conductivity, and also by i.r., H-1- and C-13-n.m.r. spectra.