Jahn—Teller coupling in the [Xtilde] ²E ground states of the CF₃O and CF₃S radicals

Fluorocarbon oxy and peroxy radicals

“…The gas phase data of the fluorescence excitation spectra [ are in general agreement with the UV matrix data [72]. However, there are disagreements between the gas phase fundamentals in the electronic ground state, deduced from the dispersed fluorescence spectrum [71], and the IR matrix data [72]. A possible explanation is, that the zero point vibrational energy of CF 3 O is higher than the Jahn-Teller splitting of the free radical in the gas phase, leading to an effective C 3v symmetry.…”

“…From the rotational fine structure of the transitions it was concluded that CF 3 O maintains C 3v symmetry in both the ground and excited state [67,68]. Five fundamentals, Jahn-Teller and spin-orbit coupling constants of high accuracy in the ground state have been determined from dispersed fluorescence spectroscopy on jet-cooled CF 3 O radicals [71]. In all the above experimental studies the CF 3 O radicals were usually generated either by excimer laser photolysis (l ¼ 193 nm) of CF 3 OF or CF 3 OOCF 3 [67,68,70], or by thermal dissociation and IR multiphoton excitation with a CO 2 laser of CF 3 OOCF 3 [69].…”

“…Later the IR band was also observed in another matrix isolation experiment [33]. Subsequently several laser-induced fluorescence [67][68][69][70] and dispersed fluorescence [69][70][71] spectra of CF 3 O radicals were recorded in the gas phase. From the analyses of laserinduced fluorescence excitation spectra of jet-cooled CF 3 O radicals, the origin of the A 2 A 1 X 2 E transition was found to begin at 28552 cm À1 and three fundamentals in the electronic excited state n 3 ¼ 635, n 5 ¼ 626, and n 6 ¼ 426 cm À1 have been detected [68].…”

Equation‐of‐motion coupled‐cluster study of Jahn–Teller effect in X2E CF3O• and CF3S•

“…The CF 3 O and CF 3 S radicals have been studied experimentally during the last three decades 2, 6–16, although much less extensively than their hydrogen analogues CH 3 X ( X = O, S). Meanwhile, the trifluoromethoxy radical CF 3 O invokes interest as a possible intermediate in the ozone depletion cycle 17.…”

“…Meanwhile, the trifluoromethoxy radical CF 3 O invokes interest as a possible intermediate in the ozone depletion cycle 17. Spectroscopic studies of CF 3 O were carried out using laser induced fluorescence (LIF) 2, 6–8, infrared and ultraviolet absorption spectroscopy 9, and fluorescence depletion techniques 10. Kinetic studies of reactions that involve CF 3 O were performed with use of mass spectrometry and infrared spectroscopy techniques 11–16.…”