Three Luminescent Copper(I) Iodide Clusters with Phosphine Ligands: Synthesis, Structure Characterization, Properties and TD-DFT Calculations

Abstract

Three new luminescent copper(I) iodide complexes with their respective phosphine ligands, namely [Cu(μ 2-I)(o-Anisyl3P)]2·CH3CN (1), [Cu(μ 3-I)(m-Anisyl3P)]4 (2) and [Cu(μ 3-I)(p-Anisyl3P)]4 (3) (Anisyl = methoxyphenyl), have been synthesized by reacting CuI with the phosphine ligand in 1:1 molar ratio. All complexes were characterized by spectroscopic analysis (IR, UV–Vis), elemental analysis, and photoluminescence study. Single-crystal X-ray diffraction revealed that complex 1 is a di-nuclear cluster structure, while both of complex 2 and 3 are cubic-like tetra-nuclear cluster structures. All complexes exhibit intense blue-green luminescence in the solid state. The excited states of all complexes have been assigned as halide-to-ligand charge transfer state mixed with metal-to-ligand charge transfer character based on the TD-DFT calculations. The complex 2 and 3 are thermally stable according to thermogravimetric analysis so that they are suitable for applying in luminescent devices.