Deprotonation of Cp2Ti(SH)(2) with mononuclear rhodium and iridium compounds: A new route to trinuclear early-late heterobimetallic complexes

The reaction of Cp2Ti(SH)(2) with [M(acac)(diolefin)] (acac = acetylacetona te) yields the complexes [Cp(acac)Ti(mu(3)-S)(2){M(diolefin)}(2)] (M = Rh, diolefin = 1,5-cyclooctadiene (cod) (1); diolefin = tetrafluorobenzobarrele ne (tfbb) (2); M = Ir, diolefin = Cod (3)). The formation of the trinuclear heterobimetallic complexes results from a complex reaction involving the d eprotonation of the hydrosulfido ligands along with the addition of the lat e-metal fragment(s), followed by the release of cyclopentadiene and the coo rdination of acetylacetonate to the titanium center. Similarly, the reactio n of Cp2Ti(SH)(2) with [M(quinol)(diolefin)] (quinol = 8-oxyquinolinate) gi ves the complexes [Cp(quinol)Ti(mu(3)-S)(2){M(diolefin)}(2)] (NI = Rh, diol efin cod (4); tfbb (5); M = Ir, diolefin = cod (6)), which incorporate the 8-oxyquinolinate ligand. The d(0)-d(8) trinuclear early-late heterobimetall ic complexes exhibit triangular TiRh2 and TiIr2 cores doubly capped by two mu(3)-sulfido ligands. Deprotonation of Cp2Ti(SH)(2) with the mononuclear c arbonyl complexes [M(acac)(CO)(2)] (M = Rh, Ir) yields the ion-pair complex es [Cp2Ti(acac)][M-3(mu(3)-S)(2)(CO)(6)] (M = Rh (7); M. = Ir (8)), which r esult from complete transference of the sulfide ligands to the d(8) metal c enters. Carbonylation of the diolefin complexes [Cp(acac)Ti(mu(3)-S)(2)(M(d iolefin)}(2)] or [Cp(quinol)Ti(mu(3)-S)(2){M(diolefin)}(2)] yields the comp ounds [Cp(acac)Ti(mu(3)-S)(2)(M(CO)(2)}(2)] (M = Rh (9); M = Ir (10)) and ( Cp(quinol)Ti(mu(3)-S)(2){M(CO)(2)}(2)] (M = Rh (11); M. = Ir (12)), respect ively. Replacement reactions on the carbonyl complexes with triphenylphosph ine give the disubstituted complexes [Cp(acac)Ti(mu(3)-S)(2){M(CO)(PPh3)}(2 )] (M = Rh (13); M = Ir (14)) or [Cp(quinol)Ti(mu(3)-S)(2)(M(CO)(PPh3)}(2)] (M = Rh (15); M = Ir (16)), which are obtained as mixtures of cis and tran s isomers. The molecular structures of complexes 1 and 8 have been determin ed by X-ray diffraction methods.