| The oxidative addition chemistry of Ru(CO)(,2)(triphos) triphos = 1,1,1-tris(diphenylphosphinomethyl)ethane and the chemistry of the thereby formed ruthenium(II) complexes have been examined. The complex behaves as would be expected for an activated but saturated d('8) complex. Steric hindrance and trans-influence from phosphorus are important factors. Additions of methyl iodide and benzyl bromide proceed cleanly to yield the alkyl complexes Ru(CO)(,2)R(triphos) ('+)X('-) (R = Me, X = I; R = Bz, X = Br). Addition of ethyl iodide and allyl bromide also yields the alkyl complexes (R = Et, (sigma)-allyl), but the halo complexes, Ru(CO)(,2)X(triphos) ('+) and Ru(CO)X(,2)(triphos) (X = Br, I), are formed too, and addition of (alpha)-methylbenzyl bromide gives predominantly halo complexes. The alkyl complexes are remarkably stable. Neither CO insertion nor replacement of CO with the halide anion is seen. The (sigma)-allyl complex is converted to Ru(CO)((pi)-allyl)(triphos) ('+) by treatment with Me(,3)N(--->)O. Addition of dry HCI to Ru(CO)(,2)(triphos) yields the hydride, Ru(CO)(,2)H(triphos) ('+), which is stable to large excess of HCI and has an acidity comparable with that of acetic acid. Reaction of Ru(CO)(,2)(triphos) with acetyl chloride yields the hydride and ketene, possibly via the acetyl complex Ru(COMe)(CO)(,2)(triphos) ('+).;Treatment of Ru(CO)(,2)R(triphos) ('+) with Me(,3)N(--->)O in the presence a ligand, L, yields the chiral complexes Ru(CO)RL(triphos) ('+) (R = Me, L = PPhMe(,2), P(OMe)(,3), CN('t)Bu, CN('s)Bu, I('-), CI('-); R = Bz, L = CN('t)Bu, CN('s)Bu).; Ru(CO)(Me)(CN('t)Bu)(triphos) ('+) was resolved and the absolute configuration of the (+)-enantiomer was determined by X-ray crystallography. Electrophilic cleavage with an excess of CI(,2), I(,2), HgCI(,2) or HCI yields the chiral halo complexes, Ru(CO)X(CN('t)Bu)(triphos) ('+).;The carbonyl resonances in the ('13)C ('1)H NMR spectra of the dicarbonyl complexes and the tricarbonyl complex, Ru(CO)(,3)(triphos) ('2+), contain information about the relative sign of the ('2)J(,C-P) coupling constants. The trans coupling constant is positive and larger than the cis coupling constant, which is negative. The first measurement of the trans isotope shift of ('31)P caused by trans ('13)CO in a transition metal complex is reported. (Abstract shortened with permission of author.);The halo complexes, Ru(CO)(,2)S(triphos) ('+) (X = Cl, Br, I) 121 , are converted to Ru(CO)(,3)(triphos) ('2+) upon treatment with CO in the presence of aluminum trichloride. The tricarbonyl complex is highly electrophilic and reacts with NaBH(,3)CN, EtOH and H(,2)O to give Ru(CO)(,2)(CHO)(triphos) ('+), Ru(CO)(,2)(COOEt)(triphos) ('+) and Ru(CO)(,2)H(triphos) ('+) respectively. |
