51922-76-0Relevant academic research and scientific papers
Light-enhanced displacement of methyl acrylate from iron carbonyl: Investigation of the reactive intermediate via rapid-scan fourier transform infrared and computational studies
Muhammad, Sohail,Moncho, Salvador,Li, Bo,Kyran, Samuel J.,Brothers, Edward N.,Darensbourg, Donald J.,Bengali, Ashfaq A.
, p. 12655 - 12660 (2013/11/19)
The thermal displacement of methyl acrylate from Fe(CO)4(η 2-CH2=CHCOOMe) by phosphine ligands is a relatively slow reaction requiring several hours at elevated temperatures. In the present study, it is observed that photolysis of the tetracarbonyl complex with UV light activates the process such that the reaction is complete within a few seconds. This rate enhancement is due to the formation of an intermediate η4 complex where the organic C=O and C=C units of methyl acrylate occupy axial and equatorial coordination sites on the Fe center, respectively, following photochemical CO loss. The displacement of methyl acrylate from this photolytically generated intermediate is facile with a remarkably low barrier of 8.7 kcal/mol. Density functional theory calculations support these experimental observations.
Low-temperature photochemistry of matrix-isolated Fe(CO)4 complexes of α,β-unsaturated esters: C=C vs. ester group coordination
Gerhartz, Wolfgang,Grevels, Friedrich-Wilhelm,Klotzbücher, Werner E.
, p. 1850 - 1856 (2008/10/08)
Photolysis of various (η2-olefin)Fe(CO)4 complexes of α,β-unsaturated esters in low-temperature matrices shows that in all cases detachment of CO is the predominant photoreaction. However, instead of the expected (η2-olefin)Fe(CO)3 species three other Fe(CO)3 complexes are observed, in which the ester group is involved in bonding to the metal. Spectroscopic data indicate bonding of the organic ligand to the Fe(CO)3 moiety (a) in a η4-1-oxadiene type fashion, (b) via C=C double bond and the ester O-R group, and (c) solely via the ester carbonyl group. Under selective irradiation conditions haptotropic rearrangements involving these three complexes take place. For comparison the photolytic behavior of a (η4-vinyl ketone)Fe(CO)3 complex was investigated. Furthermore, studies in nitrogen-containing matrices aid in the assignments. In carbon monoxide containing matrices the photolytic detachment of the olefinic moiety, in addition to CO photodissociation, is indicated by the formation of Fe(CO)5.
