The new ligand 6-mercapto-2(1H)-pyridone (H(2)PySO) has been prepared in good yield by reaction of 6-chloro-pyridin-2-ol with NaSH. Reaction of the salt K(2)PySO, generated in situ, with the appropriate complex [M(mu-Cl)(diolefin)](2) affords the tetranuclear complexes [M(4)(mu-PySO)(2)(diolefin)(4)] [M = Rh, diolefin = 1,5-cyclooctadiene (cod) (1), tetrafluorobenzobarralene (tfbb) (2); M = Ir,...