Syntheses and structural studies of several diynyl-ruthenium complexes and their adducts with cyano-alkenes

Abstract

Herein are described some continuing investigations into the reactions of cyano-alkenes with diynyl-ruthenium complexes which have resulted in the preparation and characterisation of diynyl-ruthenium compounds Ru(C≡CC≡CR)(PP)Cp [R = Ph, PP = dppe; R = Fc, PP = dppf; R = CPh=CBr₂, PP = (PPh₃)₂], together with the polycyanobutadienyls Ru{C≡CC[=C(CN) ₂]CR=CR′(CN)}(PP)Cp′ [R = Fc, (PP)Cp′ = (dppf)Cp; R = H, SiMe₃, (PP)Cp′ = (dppe)Cp*] formed by [2 + 2]-cycloaddition of the cyano-alkenes to the outer C≡C triple bonds and subsequent ring-opening reactions. Single-crystal XRD molecular structure determinations of six complexes are reported.