Syntheses, structures and properties of two mononuclear copper(I) complexes with N-heterocyclic ligands

Abstract

Two mononuclear Cu(I) complexes, [Cu(PBO)(PPh₃)₂]·PF₆·CH₂Cl₂ (1) and [Cu(PBM)(PPh₃)₂]·PF₆ (2) (PBO = 2-(2′-pyridyl)benzoxazole, PBM = 2-(2′-pyridyl)benzimidazole, PPh₃ = triphenylphosphine), have been synthesized and characterized by elemental analyses, IR, single crystal X-ray diffraction, fluorescence spectroscopy, and cyclic voltammetry. The structural analysis revealed that in 1 and 2, the Cu(I) ions are four-coordinate and the coordination geometry around the Cu(I) is distorted tetrahedral. Photoluminescent investigation shows that 1 and 2 exhibit distinct tunable green (523 nm)-to-yellow (557 nm) photoluminescence by varying the N-heterocyclic ligands. Electrochemical properties of 1 and 2 have been investigated by cyclic voltammetry. The results suggest the frontier molecular orbits and the HOMO-LUMO energy gaps of these cuprous complexes are effectively adjusted through the introduction of different N-heterocyclic ligands.

Keywords:

• Copper(I) complex
• photoluminescence
• crystal structure
• electrochemical
• N-heterocyclic ligand

Disclosure statement

No potential conflict of interest was reported by the authors.

Additional information

Funding

The present research was supported by the Foundation of A Hundred Youth Talents Training Program of Lanzhou Jiaotong University [grant number 152022], Natural Science Foundation of Gansu Province [grant number 17JR5RA090], and National Natural Science Foundation of China [grant number 21367017].