IR and UV Absorption Spectrum of the Trifluoromethoxy Radical, CF3O·, Isolated in Rare Gas Matrices

Abstract

The trifluoromethoxy radical is prepared in high yields by vacuum flash pyrolysis of CF3OC(O)OOC(O)OCF3 or CF3OC(O)OOCF3 highly diluted in inert gases, and subsequently isolated in inert gas matrices by quenching the product mixture at low temperatures. In the IR spectrum, six fundamentals have been observed and Cs symmetry is concluded for the matrix-isolated CF3O· radical by comparison with predicted band positions and band intensities from ab initio calculations. This finding is at variance with results from the analysis of the rotational resolved fluorescence excitation spectra and dispersed fluorescence spectra of gaseous CF3O· radicals, where C3v symmetry was found. Possible explanations for this discrepancy are given. The UV spectrum in the spectral region 28000−43000 cm-1 has been measured for the first time, and two different electronic transitions are observed. The structure of the low energy transition A2A1 ← X2E is in agreement with that in previous laser induced fluorescence spectra. Four vi...