A theoretical probe on the ground- and excited-state properties of heterobinuclear Au–Pt complex with phosphine ligands: Comparison with analogous homobinuclear Au–Au and Pt–Pt complexes

The structures of heterobinuclear complex, [AuIPtII(CN)2(PH2CH2PH2)2]+ (2), in the ground and lowest-energy triplet excited states were optimized by the MP2 and unrestricted MP2 methods, respectively. The metal-localized transition shortens the Au–Pt distance about 0.321 Å in the excited state with respect to 2.912 Å one in the ground state. This is further evident in the calculated stretching frequencies and bond orders of Au–Pt. The experimental absorption spectra are well reproduced by the time-dependent density functional theory (TD-DFT) calculations. The present investigation was compared with the previous results of the homobinuclear [ Au 2 I ( PH 2 CH 2 PH 2 ) 2 ] 2 + (1) and trans - [ Pt 2 II ( CN ) 4 ( PH 2 CH 2 PH 2 ) 2 ] (3).