We illustrate the use of pulsed-laser irradiation to promote homogeneous organometallic catalysis under mild conditions in the liquid phase. We concentrate on the Iron carbonyl catalyzed isomerization of olefins. Kinetics data on the Fe(CO)5/1-pentene system establish the sequence of photolytic events leading from Fe(CO)5 starting material through Fe(CO)4(pentene) catalyst precursor to the true photocatalyst, Fe(CO)3(pentene). Measurement of the average lifetime of the photocatalyst with respect to reversion to its inactive, precursor form, combined with a knowledge of the photocatalytic quantum yield establishes the turnover rate under our conditions, which is a fast 104 s-1. We also find that Fe(CO)5 photocatalytic quantum yields are temperature dependent with an apparent activation energy of 2.8 kcal mol-1. We present a mechanistic analysis of the isomerization cycle, which compares and contrasts the reactivity of group 8 coordinatively unsaturated organometallic intermediates with those of group 6.
|Original language||English (US)|
|Number of pages||8|
|Journal||Industrial and Engineering Chemistry Product Research and Development|
|State||Published - Mar 1 1984|
ASJC Scopus subject areas
- Chemical Engineering(all)
- Industrial and Manufacturing Engineering