Theoretical studies on metal-metal interaction and luminescence of a dinuclear [AuS2PH2]2 complex

The ground- and excited-state structures of [AuS2PH2](2) are optimized by the MP2 and CIS methods, respectively. The calculated Au-Au distances of [AuS2PH2](2) indicate the presence of metallophilic attraction between the two Au atoms, which is weak in the ground state structure (Au-Au distance: 3.073 angstrom) but greatly enhanced in the lowest-energy triplet excited-state structure (Au-Au distance: 2.716 angstrom). On the basis of the MP2- and CIS-optimized structures, the TD-DFT method is employed to calculate the spectra of [AuS2PH2](2) and the results show that [AuS2PH2](2) possesses the (1.3)[d*(sigma)(Au)s(sigma)(Au)] lowest-energy excited states. In the luminescence, the Au-Au interaction plays a key role and the strong Au-Au interaction can result in a red shift to the visible region. (C) 2010 Elsevier B.V. All rights reserved.