Matrix isolation studies of alkyl radicals. The characteristic infrared spectra of primary alkyl radicals

Abstract

28) The mass spectrometer was obtained through the National Science Foundation Instrument Grant GP-32797 to the University of Minnesota. We are grateful to Dr. Roger Upham for his very resourceful operation of the instrument. (29) A. J. Gordon and R. A. Ford, "The Chemist's Companion", Wiley,

CH stretch/internal rotor dynamics in ethyl radical: High-resolution spectroscopy in the CH3-stretch manifold

“…The effect of hyperconjugation in alkyl radicals with ␤-methyl groups has been a topic of long-standing interest, as studied via Fourier transform infrared ͑FTIR͒ spectroscopy in Ar matrices 27,32,[37][38][39][40][41][42] and supported by theoretical calculations. 27,28,[32][33][34]37,39,43 Common to all these radical spectra is a strong vibrational band around 2850 cm −1 , which is unusually low in frequency compared with the corresponding closed-shell systems and can be assigned to a hyperconjugated ␤-CH bond.…”

“…27,28,[32][33][34]37,39,43 Common to all these radical spectra is a strong vibrational band around 2850 cm −1 , which is unusually low in frequency compared with the corresponding closed-shell systems and can be assigned to a hyperconjugated ␤-CH bond. 41 Most importantly, this hyperconjugated band is also present in partially deuterated ethyl species, e.g., CHD 2 CH 2 , which provide direct evidence against this redshift reflecting Fermi resonance coupling with the bending overtone state.…”

Evaluation of density functional theory in the bond rupture of octane

“…3c, 7 The question of whether these distortions are due to isolated radical or matrix effects has not yet been resolved. All of these difficulties make the problem especially suitable to theoretical predictions, which are able to determine the structures of isolated radicals.…”

The Infrared Spectra of Alkyl Radicals: The Low Temperature Photochemical Decomposition of Diacyl Peroxides

“…In a similar manner complete infrared spectra of the ethyl [3], n-propyl and n-butyl radicals have been obtained by photolysis of propionyl (V), butyryl (VI) and pentyryl (VII) peroxides in argon matrices.…”