Reactions of (Cyclo­penta­di­enyl­idene­hydrazono)tri­phenyl­phos­phorane with Chloro­ruthenium(II) Complexes and Substituent Effect on the Thermodynamic Trend in the Migratory-Insertion Reactions of Chloro­ruthenium–Alkyl­idene Complexes

Reactions of (cyclo­penta­di­enyl­idene­hydrazono)­tri­phenyl­phosphorane with RuCl2(PPh3)3 or (η6-cymene)­RuCl2(PPh3) in toluene produced the chloro­cyclo­penta­di­enyl complex (η5-C5H4Cl)­RuCl­(PPh3)2, which was likely formed through the cyclo­penta­di­enyl­idene intermediate RuCl2{C­(C4H4)}­(PPh3)2. Treatment of (η6-cymene)­RuCl2(PPh3) with (cyclo­penta­di­enyl­idene­hydrazono)­tri­phenyl­phosphorane in methanol gave [(η5-C5H4Cl)­Ru­(η6-cymene)]+. Computational studies reveal that the thermodynamic stability of the analogous chlororuthenium complexes RuCl2(CRR′)­(PPh3)2 and [RuCl­(CRR′)­(PMe3)­(η6-C6H6)]+, with respect to the formation of the corresponding η5-chloropentadienyl complexes via a migratory carbene-insertion reaction is in the order of cyclo­penta­di­enyl­idene < indenylidene < fluorenylidene < phenylcarbene.