Theoretical insights into the electronic structure and photophysical properties of a series of tetranuclear Cu(I) complexes

The electronic structure and photophysical properties of four tetranuclear Cu(I) complexes have been investigated by using density functional theory and time-dependent density functional theory calculations. The four complexes are tetranuclear structure with four Cu(I) centers bridged by four chlorine atoms. Complex 3 has the strongest electron injection ability due to the largest electron affinity value. The lowest lying singlet→singlet absorption of complexes 1–4 is located at 412, 395, 509, and 578 nm, respectively. The lowest energy emissions of complexes 1–4 are localized at 495, 511, 615, and 619 nm, respectively. The calculated results show that the complex 4 possibly possesses a high phosphorescence quantum efficiency. This study is useful for obtaining a further understanding of the effect of various substituents of ligands on electronic structure and photophysical properties to search for good Cu(I) complexes in organic light-emitting devices.