Metal Poly(Benzimidazol‐1‐yl)borates. Synthesis and Spectral Characterization of Some Lanthanide Chelates of Hydridotris‐ and Tetrakis(Benzimidazol‐1‐yl)borate Anions

Abstract

Complexes of La(III), Nd(III), Pr(III), Sm(III), Tb(III), Dy(III), Ho(III), Er(III) and Yb(III) with hydridotris‐ and tetrakis(benzimidazol‐1‐yl)borate anions (L¹ and L²) have been prepared and characterized. The spectral parameters β, b^1/2, δ% and η, evaluated from the electronic spectra of the Pr, Nd, Sm, Ho and Er complexes, suggest the presence of a weak covalent contribution in the metal‐ligand bond. The IR spectral data reveal that both L¹ and L² behave as tridentate ligands coordinating via the pyridyl and pyrrolic nitrogen atoms of the benzimidazolyl groups.

Acknowledgment

The authors are thankful to the Head, Department of Chemistry, Jamia Millia Islamia, New Delhi, for providing research facilities.