Reversible Complexation of Ethylene by a Silylene under Ambient Conditions
Lips, F., Fettinger, J., Mansikkamäki, A., Tuononen, H., & Power, P. (2014). Reversible Complexation of Ethylene by a Silylene under Ambient Conditions. Journal of the American Chemical Society, 136 (2), 634-637. doi:10.1021/ja411951y
Published inJournal of the American Chemical Society
© 2013 American Chemical Society. This is a final draft version of an article whose final and definitive form has been published by ACS. Published in this repository with the kind permission of the publisher.
Treatment of toluene solutions of the silylenes Si(SArMe6)2 (ArMe6 = C6H3-2,6(C6H2-2,4,6-Me3)2, 1) or Si(SArPri4)2 (ArPri4 = C6H3-2,6(C6H3-2,6-Pri2)2, 2) with excess ethylene gas affords the siliranes (ArMe6S)2tiebar above startSiCH2tiebar above endCH2 (3) or (ArPri4S)2tiebar above startSiCH2tiebar above endCH2 (4). Silirane 4 evolves ethylene spontaneously at room temperature in toluene solution. A Van’t Hoff analysis by variable-temperature 1H NMR spectroscopy showed that ΔGassn = −24.9(2.5) kJ mol–1 for 4. A computational study of the reaction mechanism using a model silylene Si(SPh)2 (Ph = C6H5) was in harmony with the Van’t Hoff analysis, yielding ΔGassn = −24 kJ mol–1 and an activation energy ΔG⧧ = 54 kJ mol–1.