Homologation of olefins with methane on transition metals

Abstract

it possible to take a set of generic skeletal force constants and use these for deriving structures with acceptable accuracy. As we have shown, the skeletal force constants are not generally transferable. If, however, one only wishes to obtain good structures of linear metallocenes, these force constants can be obtained for the metals in Table VI11 by simply using those of ferrocene as a generic set, provided the correct equilibrium bond lengths and angles are used. This will probably apply even for somewhat strained linear metallocenes.Acknowledgment. This work was supported by grants from the National Institutes of Health. Homologation of Olefins with Methane on Transition MetalsTijs Koerts,+ Piet A. Leclercq Abstract: Alkylation of olefins using methane has been realized on transition metal catalysts. The main problem is to get methane dissociatively adsorbed together with an olefin. This is due to the difficult activation of the strong tetrahedral C-H bonds of methane. To react methane with an olefin, a reaction sequence is used consisting of three steps. First methane is dissociatively adsorbed between 600 and 800 K on a reduced transition metal catalyst. After cooling, an olefin is coadsorbed at a temperature between 300 and 400 K. Upon subsequent hydrogenation carbon-carbon bond formation occurs. The mechanism appears to be related to that occurring in the Fischer-Tropsch reaction. After hydrogenation the reaction cycle can be repeated. Methane addition to ethene, propene, and acetylene is demonstrated to occur using silica-supported ruthenium and cobalt catalysts. With 13CH4 it was shown that propane and butane are formed both by self-homologation of ethene and propene, respectively, as well as by methane incorporation. Carbon scrambling according to the metathesis reaction is very slow.

Direct conversion of methane under nonoxidative conditions

“…Van Santen and co-workers also demonstrated that the homologation of olefins (C 2 H 4 , C 3 H 6 , C 2 H 2 , etc.) with methane could occur over Ru/SiO 2 and Co/SiO 2 catalysts [15].…”

Positron emission imaging in catalysis

“…Labeled CO is then used in a two-step alkene homologation reaction previously developed in this laboratory [39]. 11 CO is pulsed over a vanadiumpromoted Ru/SiO2 catalyst at 350°C.…”

Novel catalysts for methane activation. Final progress report, September 30, 1992--April 30, 1996

“…The mixture was stirred for 24 hours, and the toluene removed under vacuum to produce the reconstituted fullerene soot.…”