Fe=B Double Bonds: Synthetic, Structural, and Reaction Chemistry of Cationic Terminal Borylene Complexes

摘要: Application of halide abstraction chemistry to asymmetric haloboryl complexes (η5-C5Me5)Fe(CO)2B(ERn)X leads the first synthetic route cationic multiply bonded group 13 diyl species, [(η5-C5Me5)Fe(CO)2B(ERn)]+. The roles steric bulk and π electron release within ERn substituent in generating tractable borylene have been probed, as has nature counterion. A combination spectroscopic, structural, computational techniques conclusion that bonding such [(η5-C5Me5)Fe(CO)2B(Mes)]+ is best described an FeB double bond composed B→Fe σ donor Fe→B back-bonding components. An extended study fundamental reactivity systems reveals this dominated not only by nucleophilic addition at boron but also iron-centered substitution leading overall displacement ligand.