28761-00-4Relevant articles and documents
Formation of β-Fluoroethyl Radical and Closed-Shell Products in Reactions of Photogenerated Fluorine Atoms with Ethene in Solid Argon
Misochko, Eugenii Ya.,Benderskii, Alexander V.,Wight, Charles A.
, p. 4496 - 4502 (2007/10/03)
Solid-state reactions of F atoms with ethene molecules were initiated by UV photolysis of dilute solutions of F2 and C2H4 in solid Ar.Products stabilized in the matrix were detected by infrared spectroscopy.Experiments were conducted at different temperatures in order to distinguish reactions in matrix-isolated F2-C2H4 complexes (at 16 K) from reactions of diffusing thermal F atoms (at 26 K).Comparison with the kinetic EPR data (Benderskii, V.A. et al.Mendeleev Commun. 1995, 6, 245) permitted the identification of the infrared spectrum of the β-fluoroethyl radical, which is the main product of the F + C2H4 reaction.Frequencies and absolute absorption intensities of the eight strongest infrared bands of β-C2H4F are reported.Photolysis of isolated F2-C2H4 complexes forms the closed-shell products C2H3F-HF and trans- and gauche-1,2-C2H4F2 with relative yields 0.6:0.2:0.2.Successive addition of two thermal F atoms to an isolated C2H4 molecule forms only the two conformers of 1,2-C2H4F2.The difference between product branching ratios of the latter reaction and the direct photoinduced reaction of F2-C2H4 complexes is qualitatively explained by the difference in size of the reaction cages and excess energies of the vibrationally excited intermediate (C2H4F2)*.
