POLYMERIC METAL DIHYDRIDOBIS(BENZIMIDAZOLYL)BORATES - SYNTHESIS AND SPECTRAL PROPERTIES OF SOME LANTHANIDE CHELATES OF DIHYDRIDOBIS(BENZIMIDAZOLYL)BORATE

Lanthanide complexes with dihydridobis(benzimidazolyl)borate (Lb(C14H1 2N4B)(2)Cl.H2O) [where Ln = Pr(III), Nd(III), Sm(III), Dy(III), Ho(III ), Er(III) and Yb(III)] have been synthesized and characterized by ele mental analyses, magnetic susceptibility, IR and electronic spectra. T he Dy(lll) and Yb(lll) complexes have also been studied by thermogravi metric analysis. The nephelauxetic ratios (beta), the bonding paramete rs (b(1/2)), Sinha's covalency parameters (delta%) and covalency angul ar parameters (eta) have been calculated for the complexes of Pr(III), Nd(III), Sm(III), Ho(III) and Er(III). A seven-coordinated polymeric structure has been proposed for these complexes.