Dinuclear rhodium complexes containing a linear C2RhC4RhC2 chain

The reaction of trans-[RhCl(=C=CHPh)(PiPr(3))(2)] (1) and trans-[RhCl(=C=CMe2)(PiPr(3))(2)] (3) with 50% aqueous NaOH, in the presence of TEBA, afforded the hydroxorhodium complexes trans-[Rh(OH)(=C=CRR')(PiPr(3))(2)] (2,4) in good to excellent yield. Compound 2 (R = H, R' = Ph) reacted with D2O to give trans-[Rh(OD)(=C=CHPh)(PiPr(3))(2)] (2-d) and with Bronsted acids HX (X = CF3CO2, OPh, C=Ph) to yield the corresponding derivatives trans-[Rh(X)(=C=CHPh)(PiPr(3))(2)] (5-7), respectively. Treatment of 2 and 4 with Ph-3-SnC=CC=CSnPh3 also led to the displacement of the hydroxo ligand and to the formation of the dinuclear complexes trans,trans-[(Rh(=C-CRR')(PiPr(3))(2)](2)(mu-C-4)] (8,9) in 75-80% yield. The X-ray crystal structure analysis of 9 revealed the presence of a linear l0-atom C=C=RhC=CC=CRh=C=C chain with the midpoint of the central C-C bond as a crystallographic center of symmetry.