Cationic Ruthenium Hydrido−Carbonyls Derived from Metallocene-Based Pincers: Unusual Rearrangements and H2 Evolution with Formation of Cationic Ruthenium Metallocenylidenes

Cationic ruthenium hydrido-carbonyls {RuH(CO)[tBuP,CH,PM]}BArF4 (M = Fe, 3; M = Ru, 4) (ArF = 3,5-(CF3)2C6H3) obtained in the reaction of H2 with RuCl(CO)[tBuP,C,PM] (M = Fe, 1; M = Ru, 2) in the presence of NaBArF4 add CO smoothly, giving the corresponding dicarbonyl complexes {RuH(CO)2[tBuP,CH,PM]}BArF4 (M = Fe, 11; M = Ru, 12). According to X-ray analysis of 11 and 12, addition of extra CO to complexes 3 and 4 leads to strengthening of the C(1)−H(1)···Ru(1) agostic interaction. Simultaneously, CO addition to 3 and 4 triggers a sequence (up to three steps) of unprecedented intramolecular rearrangements including migration of H atoms. First metallocenylidene complexes {Ru(CO)2[tBuP,C,PM]}BArF4 (M = Fe, 15; M = Ru, 16) were obtained in the course of these rearrangements accompanied by H2 evolution.