Complexes of the platinum metals. Part 25. Reactions of ruthenium and osmium nitrosyls [MH(NO)(PPh3)3] and [M(NO)2(PPh3)2] with perfluorocarboxylic acids: X-ray crystal structure determination of nitrosyl(trifluoroacetato)(trifluoroacetohydroximato-OO′)bis(triphenylphosphine)osmium(<scp>II</scp>)–dichloromethane (1/1)

Ruthenium and osmium hydridonitrosyl complexes, [MH(NO)(PPh3)3], react with perfluorocarboxylic acids RCO2H (R = CF3 or C2F5) to afford the products [Ru(O2CR)3(NO)(PPh3)2] and [OsH(O2CR)2(NO)(PPh3)2] respectively. The reaction intermediates [RuH(O2CR)2(NO)(PPh3)2] and [OsH2(NO)(PPh3)3]+ have been detected in solution by 1H and 31P-{1H} n.m.r.; the latter species has been isolated and characterised as the tetraphenylborate salt. The ruthenium dinitrosyl complex [Ru(NO)2(PPh3)2] reacts with the acids RCO2H in boiling toluene or 2-methoxyethanol to afford the products [Ru(O2CR)3(NO)(PPh3)2]. The corresponding osmium complex [Os(NO)2(PPh3)2] reacts with the same acids in boiling 2-methoxyethanol and boiling toluene to yield the hydrides [OsH(O2CR)2(NO)(PPh3)2] and the novel hydroximate derivatives [[graphic omitted]R}(O2CR)(NO)(PPh3)2] respectively. Possible mechanisms for these reactions are discussed. The X-ray crystal structure of [[graphic omitted]CF3}(O2CCF3)(NO)(PPh3)2]&#183;CH2Cl2 has been determined. The crystals are triclinic, space group P, with a= 12.709(3), b= 22.694(8), c= 9.662(3)A, α= 118.28(3), β= 113.59(3), γ= 59.66(4)&#176;, and Z= 2. The structure has been refined to R(F)= 0.051 and R′(F)= 0.049 for 4 730 observed reflections. The complex contains six-co-ordinated osmium(II) bound to a chelate O,O′-trifluoroacetohydroximate(2–) ligand, a unidentate trifluoroacetate ligand, a linear nitrosyl group, and a pair of mutually cis triphenylphosphine ligands.