Molecular orbital calculation of Mössbauer parameters for Fe(CO)4 (C2H4) in low temperature matrix

Abstract

Molecular orbital calculations have been performed to obtain the electron density and electric field gradient at the iron nucleus of tetracarbonylethene iron Fe(CO)4(C2H4) produced by UV-irradiation of pentacarbonyliron cocondensed homogeneously with ethene in a low temperature matrix, so as to estimate the Mossbauer parameters of the species. Mossbauer isomer shifts δ and electron densities at iron nuclei ρ (O) of Fe(CO)n (n=5,4,3,2) as well as Fe(CO)4(C2H4) are discussed: they have fairly good linear relationship to give −0.27 mm/s/aO−3. An isomer of Fe(CO)4(C2H4) produced via thermal reactions of Fe(CO)4 with ethene in a stratified matrix is discussed by comparing the calculated and observed Mossbauer parameters.