Neutral cis-Alkyl Olefin Rhodium(I) Complexes: Models of Intermediates in Late Transition Metal Olefin Polymerization with Surprising Structure†

摘要: The reaction of the γ-agostic 14 VE complex [(κ2-dtbpm)Rh(Np)] (1) with olefins opened an access to neutral, cis-alkyl olefin complexes (κ2-dtbpm)Rh(Np)(η2-olefin) (2a/b, Np = neopentyl, ethylene, methylacrylate) bearing cis chelating bisphosphine ligand dtbpm (bis(di-tert-butylphosphino)methane, tBu2P-CH2-PtBu2). They represent first structurally characterized examples neutral Rh systems ligation, isoelectronic presumed resting states in late transition metal (e.g., Pd, Ni) catalyzed polymerization reactions. Their solid-state molecular structures revealed unexpected, non-square-planar coordination mode moiety, center C═C double bond moved 34° out P2RhCNp plane. In solution rapid dynamic processes interconvert equivalent above or below this DFT and QM/MM (ONIOM) calculations reproduce correctly minimum geometries found crystal structures. are caused by electronic effe...