Neutral, heteroleptic copper(i)-4H-imidazolate complexes: synthesis and characterization of their structural, spectral and redox properties

Abstract

Facile synthetic access to four novel, neutral, heteroleptic copper(I)-complexes, incorporating 4H-imidazolates as well as the phosphane ligands XantPhos and DPEPhos is reported. The complexes were characterized in the solid state as well as in solution by means of single crystal X-ray diffraction as well as NMR spectroscopy, mass spectrometry and elemental analysis. The copper(I)-4H-imidazolate complexes show a broad intense absorption that spans almost the entire visible range. TD-DFT calculations revealed the charge transfer character of the underlying transitions. NMR as well as electrochemical investigations and UV-Vis absorption suggest a polarization of the complexes with the negative charge pushed towards the 4H-imidazolate moiety.