Three ruthenium sulfide clusters with labile CH3CN ligands have been photochemically synthesized. Irradiation of [(cymene)(3)Ru3S2] (PF6)(2) ([1](PF6)(2)) in CH3CN gives [(cymene)(2)(CH3CN)(3)Ru3S2] (PF6)(2) ([2](PF6)(2)), which has been characterized by 'H NMR spectroscopy, ESI mass spectrometry, and chemical reactivity. Treatment of [2](PF6)2 with PPh3 gives [(cymene)(2)(CH3CN)(2)(PPh3)RU3S2](PF6)(2) ([3](PF6)(2)) and [(cymene)(2)(CH3CN)(PPh3)(2)Ru3S2](PF6)(2) ([4](PF6)(2)), while treatment with 1,4,7-trithiacyclononane (9S3) gives [(cymene)(2)(9S3)Ru3S2](PF6)(2) ([5](PF6)(2)). A crystallographic study demonstrated that the Pus core in [3](PF6)(2), [4](PF6)(2), and [5](PF6)(2) is distorted with a pair of elongated Ru-Ru bonds. Cyclic voltammetry shows that [3](PF6)(2) and [4](PF6)(2) undergo two closely spaced reversible one-electron reductions whereas [5](PF6)2 undergoes one irreversible one-electron reduction and one reversible one-electron reduction. Prolonged irradiation of [1](PF6)(2) in CH3CN causes decomposition, resulting in the pentanuclear cluster [(cymene)(4)Ru5S4](PF6)(2) ([6](PF6)(2)).