MOLECULAR-ORBITAL STUDIES OF LUMINESCENT SILVER(I) CHALCOGENIDO CLUSTERS [AG-4(MU-DPPM)(4)(MU(4)-E)](2+) (DPPM=PH(2)PCH(2)PPH(2))

The electronic structures of the mu(4)-chalcogenido silver(I) complexe s [Ag-4(mu-dppm)(4)(mu(4)-E)][O3SCF3](2) (E = S 1, Se 2 or Te 3; dppm = Ph(2)PCH(2)PPh(2)) have been calculated by use of the Fenske-Hall mo lecular orbital method. The results indicate that complexes 1-3 show s imilar electronic structures, with the highest occupied molecular orbi tal being mainly of Ag-E character while the lowest unoccupied molecul ar orbital is of metal-metal interaction character. A correlation betw een the results of these calculations with the spectroscopic propertie s of this class of complexes is described.