Theoretical studies on metal–metal interaction and σ∗(d) → σ(p) transition in binuclear platinum(II) complex,

The excited states related to the pz → dz2 transition of trans-[PtII(CN)2(PH3)2] (1), trans - [ Pt 2 II ( CN ) 4 ( PH 2 CH 2 PH 2 ) 2 ] (2) and their weakly solvated 1 · (MeCN)2 and 2 · (MeCN)2 species are studied by ab initio methods. The results indicate that the Pt–Pt interaction in dimer leads to lower-energy emissions either in the solid state or in solution with respect to monomer. The solvent molecules slightly affect the emissions of such platinum(II) complexes, different from the case in the previous studies of [ Au 2 I ( PH 2 CH 2 PH 2 ) 2 ] 2 + (4), but both agree well with the corresponding experimental observations.