319456-76-3Relevant academic research and scientific papers
Preparation and reactivity of dihydrogen complexes [MX(ii2-H2)P4]BF4 (M = Ru or Os; X = halogenide or SEt~; P = phosphite)
Albertin, Gabriele,Antoniutti, Stefano,Bordignon, Emilio,Pegoraro, Michela
, p. 3575 - 3584 (2000)
Monohydride complexes MHXP4 [M = Ru or Os; X = CP, Br, T, SEr or N3~; P = P(OEt)3, PPh(OEt)2 or PPh2OEt] were prepared by treating dihydride species MH2P4 first with CF3SO3Me and then with an excess of the anionic ligand X. In an argon atmosphere, protonation of MHXP4 with HBF4-Et2O gives dihydrogen cations [MX(n2-H2)P4+, with X = Cl, Br, I or SEt; the classical dihydride [MH2(N3)P4]+ was obtained with the azide ligand. Instead, in a hydrogen atmosphere, protonation of MHXP4 with HBF4-Et2O gives hydride-dihydrogen [MH(r)2-H2)P4]+ species, according to a proposed mechanism involving interaction of Bronsted acid with ligand X. Some [MX(Η2-H2)P4]+ cations were thermally unstable and fully characterised in solution ('H and P NMR, variable temperature Tl measurements), whereas the [OsX(η2-H2){PPh(OEt)2}4]BF4 complexes were stable and isolated as solids. Treatment of [MX(n2-H2)P4]+ cations with alkyne PhOCH gave evolution of H2 and formation of the vinylidene intermediate [MX{=C=C(H)Ph}P4]+ which, by reaction with base, afforded the final acetylide M(OCPh)XP4 derivatives. Treatment with propargyl alcohols HOCC(OH)RR' of the [MX(n2-H2)P4r cations, instead, gave propadienylidene derivatives [MX(=C=C=CRR')P4]BPh4 (M = Ru or Os; R = R' = Ph or R = Ph, R' = Me). Hydrazine complexes [MX(NH2NH2)P4]BPh4 were also prepared by substitution of the dihydrogen ligand in the new n2-H2 derivatives. The Royal Society of Chemistry 2000.
