Ab initio study of luminescent chalcogenido silver(I) clusters [Ag-4(mu-H2PCH2PH2)(4)(mu(4)-E)](2+)

Ab initio calculations have been performed on the chalcogenido silver(I) model complexes [Ag-4(mu-H2PCH2PH2)4(mu(4)-E)](2+) and their cores [Ag-4(mu(4)-E)](2+) (E = S, S, and Te) at the RHF/3-21G level, The results reveal a chalcogenido-based HOMO and metal-based LUMO. It is envisaged that the excited states of luminescent silver(I) clusters [Ag-4-(mu-dppm)(4)(mu(4)-E)](2+) bear a high parentage of ligand-to-metal charge-transfer LMCT (E(2-) --> Ag-4) character, mixed with a metal-centred MC (ds/dp) state.