918407-39-3Relevant academic research and scientific papers
Syntheses and fluxional processes of diphenyl(2-thienyl)phosphane derivatives of triosmium clusters
Kiriakidou Kazemifar, Nitsa K.,Stchedroff, Marc J.,Mottalib, M. Abdul,Selva, Simona,Monari, Magda,Nordlander, Ebbe
, p. 2058 - 2068 (2006)
Thermal treatment of [Os3(CO)12] with diphenyl(2-thienyl)-phosphane, Ph2P(C4H3S), results in the formation of [Os3(CO)12-x{Ph 2P(C4H3S)}x] (x = 1-3, 1-3), but no C-H bond activation was observed. Reaction of [H2Os 3(CO)10] with diphenyl(2-thienyl)phosphane at ambient temperature affords [HOs3(μ-H)(CO)10{Ph 2P(C4H3S)}] (4), but when the same reaction is repeated at elevated temperatures, the cyclometallated species [(μ-H)Os 3(CO)9{μ3-Ph2P(C 4H2S)}] (5) and [(μ-H)Os3(CO) 8{μ3-Ph2P(C4H2S)} {Ph2P(C4H3S)}] (6) are formed. In addition, two more products, tentatively assigned as [(μ-H)Os3(CO) 6{μ3-Ph2P(C4H2S)} {μ-Ph2P(C4H3S)}{Ph2P-(C 4H3S)}] (7) and [(μ-H)Os3(CO) 7{μ-Ph2P(C4H2S)}{(μ-Ph 2P(C4H3S)}{Ph2P(C4H 3S)}] (8) are obtained. The dynamic behaviours of 2, 5 and 6 have been studied by variable-temperature (VT) 1H and 31P{ 1H} NMR spectroscopy. The VT 31P{1H} NMR spectra of [Os3(CO)10{Ph2P(C4H 3S)}2] (2) demonstrate that a mixture of two isomers, which are in rapid exchange at room temperature, is present and that the less common cis-trans isomer, whose structure has been determined by X-ray crystallography, is favoured for this cluster. The VT 1H NMR spectra of 5 indicate the presence of two isomers which are proposed to arise from an oscillation of the σ,η2-vinyl group of the thienyl moiety between two metal atoms. A similar fluxional process is proposed to occur in 6 and the assignment of the room-temperature structure(s) of this cluster was confirmed by 1H-187Os 2D HMQC spectroscopy. In addition to 2, the solid-state structures of 3, 5 and 6 have been determined by X-ray crystallography. Wiley-VCH Verlag GmbH & Co. KGaA, 2006.
