Unexpected dehydrogenation of a cyclohexyl group at low temperature through protonation of RuH3(η5-C5Me5)(PCy3)(Cy = cyclohexyl). X-Ray structure of [(η5-C5Me5)Ru{(C6H9)P(C6H11)}2]BF4

Abstract

Low temperature protonation of RuH₃(η⁵-C₅Me₅)(PR₃)(R = Prⁱ, Ph, cyclohexyl) leads either to decomposition (R = Prⁱ), to a mixture of cis- and trans-[RuH₂(η⁵-C₅Me₅)(PR₃)₂]BF₄(R = Ph), or to dehydrogenation of a cyclohexyl group to afford the complex [Ru(η⁵-C₅Me₅){(C₆H₉)P(C₆H₁₁)₂}]BF₄ which shows a strong agostic interaction between a C–H bond of the cyclohexenyl group and the metal; a possible application of the later observation is proposed for the dehydrogenation of alkanes.