Find Paper, Faster
Example:10.1021/acsami.1c06204 or Chem. Rev., 2007, 107, 2411-2502
Linear Hydrocarbon Chain Growth from a Molecular Diruthenium Carbide Platform
Journal of the American Chemical Society  (IF15.419),  Pub Date : 2021-09-15, DOI: 10.1021/jacs.1c06586
Jun Ohata, Akira Teramoto, Hiroaki Fujita, Shin Takemoto, Hiroyuki Matsuzaka

The formation of linear hydrocarbon chains by sequential coupling of C1 units on the metal surface is the central part of the Fischer–Tropsch (F-T) synthesis. Organometallic complexes have provided numerous models of relevant individual C–C coupling events but have failed to reproduce the complete chain lengthening sequence that transforms a linear Cn hydrocarbon chain into its Cn+1 homologue in an iterative fashion. In this work, we demonstrate stepwise growth of linear Cn hydrocarbon chains and their conversion to their Cn+1 homologues via consecutive addition of CH2 units on a molecular diruthenium carbide platform. The chain growth sequence is initiated by the formation of a μ-η11-C═CH2 ligand from a C + CH2 coupling between the μ-carbido complex [(Cp*Ru)2(η-NPh)(μ-C)] (1; Cp* = η5-C5Me5) and Ph2SCH2. Then, the chain propagates via a general C═CHR + CH2 coupling and subsequent hydrogen-assisted isomerization of the resulting allene ligand μ-η13-H2C═C═CHR to a higher vinylidene homologue μ-η11-C═CH(CH2)R. By repeating this reaction sequence, up to C6 chains have been synthesized in a stepwise fashion. The key step of this chain homologation sequence is the selective hydrogenation of the μ-η13-allene unit to the corresponding μ-alkylidene ligand. Isotope labeling and computational studies indicate that this transformation proceeds via the hydrogenation of the allene ligand to a terminal alkene form and its isomerization to the μ-alkylidene ligand facilitated by the coordinatively unsaturated diruthenium platform.