Photochemistry of Iron Atoms and Dimers with Ethylene in Cryogenic Matrices. The FTIR Spectrum of Ethenyliron Hydride

Article abstract of DOI:10.1021/ja00311a054

Evidence from infrared studies shows that atomic and molecular iron interact with ethylene in two distinct ways.One type of interaction leads to the formation of the classical ?-complex known for many transition metal/ethylene systems.In this context we have isolated Fe(C2H4)n, where n >/= 2, as well as Fe2(C2H4)m, where m = 1, 2 in solid inert gas matrices.Another type of interaction deduced from the present study takes place between one or more of the hydrogen atoms of ethylene and atomic iron.Two forms of a hydrogen-bonded complex exhibit a slightly perturbed ethylene-like infrared spectrum.Perturbations on all the ethylene infrared active modes have been measured.A photoreversible oxidative-addition/reductive-elimination reaction of the form Fe(C2H4) <*> HFeC2H3 has been observed at 14 K in solid argon and krypton.One of the hydrogen-bonded complexes, Fe(C2H4), was found to be the primary precursor for formation of the insertion product, HFeC2H3.Frequencies of ten fundamental modes of HFeC2H3, HFe13C2H3, and DFeC2D3 have been measured in the 450-4000 cm^-1 infrared region.