10.1021/om101114c.s001
Samuel S. Karpiniec
Samuel S.
Karpiniec
David S. McGuinness
David S.
McGuinness
Michael G. Gardiner
Michael G.
Gardiner
Brian F. Yates
Brian F.
Yates
Jim Patel
Jim
Patel
Revisiting the Aufbau Reaction with Acetylene: Further Insights from Experiment and Theory
American Chemical Society
2011
2C
binding mode increases
chain growth
Aufbau reaction
acetylene chain growth
insertion proceeds
dimer formation
chain termination
Al
Aufbau Reaction
2011-03-28 00:00:00
Journal contribution
https://acs.figshare.com/articles/journal_contribution/Revisiting_the_Aufbau_Reaction_with_Acetylene_Further_Insights_from_Experiment_and_Theory/2676919
The first steps of acetylene chain growth at AlEt<sub>3</sub>, via migratory insertion, have been investigated both experimentally and theoretically. The first insertion into the Al−Et bond occurs readily, leading to the stable alkenyl-bridged dimer [{Et<sub>2</sub>Al(μ-CHCHEt)}<sub>2</sub>] (<b>1</b>). The alkenyl bridging mode has been observed through isolation and structural analysis of Al<sub>2</sub>Et<sub>2</sub>(OC<sub>6</sub>H<sub>3</sub>Ph<sub>2</sub>)<sub>2</sub>(μ-CHCHEt)(μ-OC<sub>6</sub>H<sub>3</sub>Ph<sub>2</sub>) (<b>2</b>), synthesized by way of controlled reaction of <b>1</b> with 2,6-Ph<sub>2</sub>C<sub>6</sub>H<sub>3</sub>OH. This stable binding mode increases the barrier to a second insertion of acetylene, as insertion proceeds through monomeric Al-acetylene adducts. The energetics of further chain growth, dimer formation, and chain termination via hydrogenolysis were investigated theoretically. The results provide further insight and explanation for previous experimental findings in relation to the Aufbau reaction with acetylene.