Reactions of {[Pd(mu-SC6F5)(mu-dppm)Pd](mu-SC6F5)}(4)center dot 2O(C2H5)(2). Crystal structures of the complexes [(Ph3P)Pd(mu-SC6F5)(mu-dppm)Pd(SC6F5)]center dot 1.4CH(2)Cl(2) and [(Ph3P)Pd(mu-SC6F5)(mu-dppm)Pd(PPh3)]SO3CF3 center dot 2CH(2)Cl(2) and ab initio MO calculations on the model systems [(H3P)Pd(mu-H2PCH2PH2)(mu-SH)Pd(PH3)](+) and [(H3P)Pd(mu-H2PCH2PH2)Pd(PH3)](2+)

{[Pd(mu-SC6F5)(mu-dppm)Pd](mu-SC6F5)}(4) reacts 1:4 with neutral ligands L to give [LPd(mu-SC6F5)(mu-dppm)Pd(SC6F5)] or 1:8 to form [LPd(mu-SC6F5)(mu-dppm)PdL](+) (dppm = bis (diphenylphosphino)methane). These binuclear complexes retain the palladium-palladium bond and the two dissimilar bridging ligands, as demonstrated by the X-ray structural determinations carried out on [(Ph3P)Pd(mu-SC6F5)(mu-dppm)Pd(SC6F5)]. 1.4CH(2)Cl(2) and [(Ph3P)Pd(mu-SC6F5)(mu-dppm)Pd(PPh3)]SO3CF3 . 2CH(2)Cl(2). Ab initio calculations on the model systems [(H3P)Pd(mu-H2PCH2PH2)(mu-SH)Pd(PH3)](+) and [(H3P)Pd(mu-H2PCH2PH2)Pd(PH3)](2+) show that the metal-metal bond arises mainly from interactions between palladium sp orbitals, which also play a predominant role in the binding with the sulfur bridge.