posted on 2016-02-21, 18:16authored byLucie Jašíková, Jana Roithová
The binding energies of unsaturated hydrocarbons (benzene,
styrene,
1-pentene, 1-pentyne, 2-pentyne, phenylacetylene, cyclooctene, 1,5-cyclooctadiene,
1,3-cyclooctadiene) with the (trimethylphosphino)gold cation have
been investigated by means of mass spectrometry and density functional
theory. It is shown that the interactions of the gold(I) cation with
C–C triple bonds are stronger than those with C–C double
bonds or with an aromatic ring. Further, the gold cation preferentially
interacts with the isolated C–C double bonds in 1,5-cyclooctadiene
and cyclooctene in comparison to the conjugated double bonds in 1,3-cyclooctadiene.
In contrast to these results, the binding energies of Au(PMe3)+ to the simplest unsaturated hydrocarbons increase in
the order acetylene < ethylene < butadiene. The effect of the
alkyl and aryl substitution and the consequence of these results for
the gold-catalyzed reactions of unsaturated hydrocarbons are discussed.