Photoassisted catalysis of the 1-pentene isomerization by iron pentacarbonyl physisorbed onto porous Vycor glass

Abstract

UV photolysis of Fe(CO)/sub 5/ physisorbed onto porous Vycor glass under a 1-pentene atmosphere leads to quantitative formation of Fe(CO)/sub 4/(1-pentene). Continued photolysis leads to an active, catalytic intermediate capable of promoting alkene isomerization. Diffuse-reflectance FTIR spectra reveal intermediates that closely resemble those found in low-temperature hydrocarbon matrices. Although the spectral similarities and isomerization quantum yield, 152 /plus minus/ 23, indicate a thermally activated ground-state catalyst, the cis/trans product ratio varies with irradiation time and differs from the expected thermodynamic ratio. 32 references, 4 figures.