[(ETA(6)-C(6)H(3)ME(3))RU(D-PEN)](2)CL-2-CENTER-DOT-4H(2)O

The structure of the title compound, bis[mu-D-3-mercaptovalinato(1- )-1 kappa N, 1:2 kappa(2)S;2 kappa N, 1:2 kappa S-bis[(eta(6)-mesitylene)ruthenium] dichloride tetrahydrate, [Ru-2(C-5-H10NO2S)(2)(eta(6)-C9H12)(2)]Cl-2.4H(2)O, contains tridentate anionic amino acid ligands, where the S atoms adopt bridging positions between the two Ru atoms resulting in a near planar Ru-S-Ru-S ring. The coordination at each Ru atom is completed by an amino N atom of the chelating ligand and the eta(6)-bonded mesitylene ring.