Synthesis and characterization of the trihalophosphine compounds of ruthenium [RuX2(eta(6)-cymene)(PY3)] (X = Cl, Br, Y = F, Cl, Br) and the related PF2(NMe2) and P(NMe2)3 compounds; multinuclear NMR spectroscopy and the X-ray single crystal structures of [RuBr2(eta(6)-cymene)(PF3)], [RuBr2(eta(6)-cymene)(PF2{NMe2})], and [RuI2(eta(6)-cymene)(P{NMe2}3)].

Treatment of the dimers [RuX2(eta(6)-cymene)]2 with PF3 in hot heptane produces the compounds [RuX2(eta(6)-cymene)(PF3)] (X = Cl, Br, I) in good yield. Difluoro(dimethylamino)phosphine and tris(dimethylamino)phosphine react similarly to produce the compounds [RuX2(eta(6)-cymene)(PF2{NMe2})] and [RuX2(eta(6)-cymene)(P{NMe2}3)]. Reaction of the dimers [RuX2(eta(6)-cymene)]2 with PCl3 and PBr3 proceeded with the production of mononuclear products which had undergone halogen exchange at ruthenium in some cases. (1)H, (13)C, (31)P, and (19)F NMR spectra have been obtained where appropriate together with ((1)H-(1)H) correlation spectroscopy (COSY) and ((13)C-(1)H)-HETCORR spectra of selected compounds. The variation of (1)J((31)P-(19)F) with the nature of the auxiliary ligand (X) in the PF3 and PF2(NMe2) complexes has been examined both experimentally and computationally using a natural localized molecular orbital-natural bond order approach. The single crystal X-ray structure of [RuBr2(eta(6)-cymene)(PF3)] has been determined at 223 K and those of [RuBr2(eta(6)-cymene)(PF2{NMe2})] and [RuI2(eta(6)-cymene)(P{NMe2}3)] at 294 K.