Copper(II) complexes of a new tetradentate bis-benzimidazolyl diamide ligand with disulfanediyl linker: synthesis, characterization, and oxidation of some pyridyl, napthyl, and benzyl alcohols

Abstract

The bis-benzimidazolyl diamide ligand 3,3′-disulfanediyl-bis-(N-((1H-benzo[d]imidazol-2-yl)methyl)propanamide) (L) having N, S, and O donors has been synthesized and utilized to prepare copper(II) complexes of general composition [Cu(L)X]·X·nH₂O, where X is Cl^– or . Ligands and complexes were characterized by elemental analysis, UV–visible, IR spectroscopy, ¹H NMR, mass spectrometry, conductance, electron paramagnetic resonance, cyclic voltammetry, fluorescence, single-crystal, and PXRD. [Cu(L)(NO₃)]NO₃·H₂O crystallizes in the monoclinic C2/c space group with one molecule in the asymmetric unit. Copper adopts a distorted octahedral geometry with four coordination sites occupied by the ligand and two sites by a bidentate nitrate. [Cu(L)(NO₃)]NO₃·H₂O has been utilized as a catalyst to oxidize alcohols with tert-butyl hydroperoxide as an alternative source of oxygen. The oxidized products have been characterized by GCMS.

Keywords:

• Copper(II) complexes
• N, S, and O donor benzimidazolyl diamide ligands
• Crystal structure
• Galactose oxidase

Acknowledgment

We gratefully acknowledge the financial support from the University of Delhi for a special grant. Thanks to AIRF (JNU) for the GCMS data.