MONO-DENTATE AND BI-DENTATE CARBOXYLATO COMPLEXES OF RUTHENIUM(IV)

Treatment of the ruthenium(IV) chloro-bridged dimer [{Ru(eta3:eta3-C10H16)Cl(mu-Cl)}2] 1 with sodium acetate or silver acetate at room temperature in acetone gives the chelate complex [Ru(eta3:eta3-C10H16)Cl(O2CMe)] 2. Refluxing 1 in trifluoroacetic acid, or reaction of 1 at room temperature with Ag[CF3CO2] gives the monodentate, dicarboxylate species [Ru(eta3:eta3-C10H16)(O2CCF3)2(OH2)] 3, which contains a tightly bound water ligand. A range of chloro and fluoro substituted carboxylato complexes has been prepared (5-9) and the 'cross-over' point between mono- and bi-dentate co-ordination determined. The hexafluoro beta-diketonate complex [Ru(eta3:eta3-C10H16)Cl{F3CC(O)CHC(O)CF3}] 10, exhibits the expected bidentate mode of co-ordination. Reaction of 1 with thioacetic acid over short reaction times yields the adduct [Ru(eta3:eta3-C10H16)Cl2{SC(OH)Me}] 11. The corresponding chelate species [Ru(eta3:eta3-C10H16)Cl(SOCMe)] 12, is formed over longer reaction times. Analogous reactions with thiopivalic and thiobenzoic acids result only in the isolation of the chelate products [Ru(eta3:eta3-C10H16) Cl(SOCR)] (R = Bu(t) 13 or Ph 14). The structures of complexes 2 and 3 have been verified by X-ray crystallography.