The reaction of [(C(5)Me(5))M(MeCN)(3)](PF6)(6) with (C(5)Me(5))(2)Ru2S4 gives the cluster compounds [(C(5)Me(5))(3)MRu(2)S(4)(Me-CN)](PF6)(2), 1(PF6)(2) (M = Rh) and 3(PF6)(2) (M = Ir). Crystallographic studies of 1(PF6)(2) show that the dication consists of an asymmetric RhRu2S4 core containing an isosceles triangle of metal atoms with a Ru-Ru bond of 2.88 Angstrom. The three metal atoms are joined by two mu(3)-eta(1):eta(2):eta(1)-S-2 units, each persulfide being monodentate toward Rh. NMR studies show that 1(2+) is stereochemically nonrigid such that the two Ru(C(5)Me(5)) resonances coalesce at higher temperatures. The dynamic processes involving 1(2+) are unaffected by added (C(5)Me(5))Rh(MeCN)(3)(2+) ruling out dissociation of the (C(5)Me(5))Rh center. Exchange of the (C(5)Me(5))Ru sites in [(C(5)Me(5))(2)(C(5)Me(4)Et)-RhRu2S4(MeCN)](PF6)(2), 2(PF6)(2), is associated with coalescence of the pairs of C(5)Me(4)Et resonances, suggesting that the dynamics in 1(2+) involve racemization. It is proposed that these dynamics proceed via the "base-free" intermediate [(C(5)RMe(5))(3)RhRu2S4](2+), wherein one S-S bond has been cleaved. Solutions of 1(2+) react with acetone to give the S-acetonyl derivative [(C(5)Me(5))(3)RhRu2S3(SCH2COCH3)]PF6, 4(PF6). This species, which is not fluxional on the NMR time scale, is a rare example of a metal sulfide cluster with a trigonal prismatic M(3)S(3) core. There is one metal-metal bond of 2.75 Angstrom between the two Ru atoms, spanned by the acetonylthio ligand. The M-S distances are nearly equivalent at 2.33 Angstrom while the S-S bonding distance is 2.12 Angstrom. This reaction is reversed by acid to give 1(2+) and acetone.