Reaction of the complexes [{Ru(η-arene)Cl₂}₂](1)(arene = C₆H₆ or C₆H₃Me₃) and [{M(η-C₅Me₅)Cl₂}₂](2)(M = Rh or Ir) with excess of various dithioacid anions gives monomeric [Ru(η-arene)(S–S)₂](3; S–S^–=[S₂PR₂]^–) and [M(η-C₅Me₅)(S–S)₂](4: M = Rh, S–S^–=[S₂PR₂]^–, [S₂CNR₂]^–, or [S₂COR]^–; M = Ir, S–S^–=[S₂CNMe₂]^– or [S₂PMe₂]^–) respectively. Analytical data together with i.r. and ¹H, ¹³C, and ³¹P n.m.r. studies show that these complexes contain both bi- and uni-dentate dithioacid groups both in the solid state and in solution. For [M(η-C₅Me₅)(S₂CNMe₂)₂](M = Rh or Ir) and [Rh(η-C₅Me₅)(S₂COEt)₂] in solution at higher temperatures, however, kinetic line-shape analysis indicates the occurrence of uni- and bi-dentate dithioacid exchange probably via a dissociatively controlled intramolecular mechanism. Reaction of (1; arene = C₆H₆) and (2; M = Rh) with [S–S]^–(1 : 1 mol ratio) gives [Ru(η-C₆H₆)Cl(S₂PPh₂)] and [Rh(η-C₅Me₅)Cl(S–S)](5; S–S^–=[S₂NMe₂]^–,[S₂PMe₂]^–, or [S₂PPh₂]^–) respectively which are useful precursors for synthesising a range of complexes such as [Rh(η-C₅Me₅)X(S₂CNMe₂)](X = Br^–, I^–, or SCN^–) and the mixed dithioacid complexes [Rh(η-C₅Me₅)(S₂CNMe₂)(S–S)](6; S–S^–=[S₂PMe₂]^–, [S₂PPh₂]^–, or [S₂COMe]^–). In methanol, (5; S–S^–=[S₂CNMe₂]^–) gives the solvated cation [Rh(η-C₅Me₅)(HOMe)(S₂CNMe₂)]⁺ which reacts with various Lewis bases (L) to give [Rh(η-C₅Me₅)(S₂CNMe₂)L][BPh₄](L = PPh₃, PMePh₂, CO, AsPh₃, or C₅H₅N). Similar complexes can also be made by reaction of [Ru(arene)Cl₂(NC₅H₅)] or [Rh(η-C₅Me₅)Cl₂(PPh₃)] with [S–S]^–(1 : 1 mol ratio) and excess of Na[BPh₄]. However, reaction of (5; S–S^–=[S₂CNMe₂]^–) with excess of Ph₂P[CH₂]PPh₂(dppe) or Ph₂PCH₂PPh₂(dppm) in methanol gives the dimeric cations [{Rh(ηC₅Me₅)(S₂CNMe₂)}₂(dppe or dppm)]²⁺(7) and with C₂(CN)₄ and Na[BPh₄] in methanol the cyanotriphenylborate complex [Rh(η-C₅Me₅)(NCBPh₃)–(S₂CNMe₂)](8) is formed.