RT info:eu-repo/semantics/article T1 Insight into cis-to-trans olefin isomerisation catalysed by group 4 and 6 cyclopentadienyl compounds A1 Chahboun, Ghaita A1 Petrisor, Cristina Elena A1 Gómez-Bengoa, Enrique A1 Royo Cantabrana, Eva A1 Cuenca Agreda, Tomás K1 Olefin isomerization K1 Molybdenum K1 Zirconium K1 Catalysis K1 Ciencia K1 Química inorgánica K1 Science K1 Chemistry, inorganic AB Intramolecular isomerisation of the pendant allyl unit present in the model compound [MoH(η5-C5H4SiMe2CH2CH=CH2)(CO)3] reported before was investigated by DFT calculations. The coordination of CO and the splitting of the agostic Mo–H interactions found in metallacyclic transition states stabilise the cis and trans hydride compounds [MoH(η5-C5H4SiMe2CH=CHCH3)(CO)3] relative to the corresponding tricarbonyl molybdenum alkyl metallacycles. A comparison with an analogous zirconium system is included. To contrastthese results with the behaviour of metal hydride cyclopentadienyl compounds, which have no intramolecular alkene functionality, group 4 and 6 derivatives such as [Zr(η5-C5H4SiMe2-η1-NtBu)(η5-C5H4SiMe2CH2CH2-η1-CH2)] (2), [MH(η5-C5HMe4)(CO)3] [M = Mo (3), W (4)], and [ZrH(η5-C5H4SiMe2-η1-NtBu)(η5-C5H4R)] [R = H (5), SiMe3 (6)] were examined as selective catalysts for the intermolecular isomerisation of the terminal olefins allyltrimethylsilane (A) and 4-methyl-1-pentene (B). Zirconium hydride compounds were the most efficient catalysts. Compound 4 catalysed the same reaction but required heating at 140 °C, whereas compound 3 was inactive due to a dehydrogenation process, which produced the dinuclear compound [Mo(η5-C5HMe4)(CO)3]2 (7). Reaction of 4 and 5 with the internal alkenes trimethyl(1-propenyl)silane (C) and 4,4-dimethyl-2-pentene (D) favoured cis-to-trans isomer conversion with poor production of the corresponding terminal olefins. PB Wiley-VCH Verlag GmbH & Co. SN 1099-0682 YR 2009 FD 2009 LK http://hdl.handle.net/10017/3833 UL http://hdl.handle.net/10017/3833 LA eng DS MINDS@UW RD 28-mar-2024