Metallophilicity in annular Ru2M2 derivatives of (HMB)RuII(tpdt) versus (Bis)-η2-dithiolate bonding in Ru2M derivatives of Cp*RuIII(tpdt) (HMB = η6-C6Me6;: Cp* = η5-C5Me5;: M = CuI, AgI,II, AuI;: tpdt=3-thiapentane-1,5-dithiolate)

The reaction of [(HMB)Ru-II(eta(3)-tpdt)] (1: HMB = eta(6)-C6Me6; tpdt = S(CH2CH2S-)(2)) with [Cu(MeCN)(4)]PF6, AgPF6, and (PPh3)AuCl gave the annular species [{(HMB)Ru-II(mu(3)-eta(1):eta(1):eta(3)-tPdt)}(2)(M)(2)](2+) [3: M = Cu-I; 3A: (M)(2) = Cu-I, Cu-I(MeCN); 4: M = Ag-I; 6: M = Au-I], isolated as PF6 salts in high yields. Complex 6 was formed in a reversible process with [{(HMB)-Ru-II(mu-eta(1):eta(3)-tpdt)}(AuPPh3)](+) (5) involving dissociation/association of PPh3. Similar reactions of [Cp*Ru-III(eta(3)-tpdt)] (2: Cp* = eta(5)-C5Me5) gave, respectively, the cationic metal-metal bonded Ru2M complexes [{Cp*Ru(mu-eta(2):eta(3)-tpdt)}(2)M](n+) (7: M = Cu-I, n = 1; 8: M = Ag-II, n = 2) and [{Cp*Ru(mu-eta(1):eta(3)-tpdt)}(AuPPh3)](+) (9), isolated as PF6 salts in 71, 73, and 72% yields, respectively. In MeCN or THF for an extended period, 9 underwent transformation to a mixture of complexes, from which [{Cp*Ru}(2){mu-eta(6)-(S(CH2)(2)S(CH2)(2)SAuPPh3)(2)}](2+) (10), containing a mu-S-2 bridge, and [{Cp*Ru(mu(3)-eta(1):eta(1):eta(3)-tpdt)}(AuPPh3)(2)](+) (11) could be identified. The new complexes, 3-9 and 11, were all spectroscopically characterized, and the X-ray crystal structures of 3-10 have been determined. Cyclic voltammetry experiments were performed on compounds 3A, 4, and 6-8 at 233 K in CH2Cl2. 7 and 8 could be oxidized and reduced in several one-electron steps to form moderately stable species with extensive electron delocalization between the RU2M atoms. An EPR spectrum of 8, a Ag(II) (d(9)) species, was obtained at liquid He temperatures.