Rotationally resolved electronic excitation spectra of the ethoxy ~B .rarw. ~X transition

Tan, X. Q.; Williamson, James M.; Foster, Stephen; Miller, Terry A.

doi:10.1021/j100139a010

Cited by 50 publications

(49 citation statements)

References 9 publications

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“…The jet-cooled LIF excitation spectrum of ethoxy has been reported by several groups [8][9][10] and selected vibrational bands in this spectrum were chosen to obtain the natural lifetimes. The lifetimes were measured using the following procedure.…”

Section: Methodsmentioning

confidence: 99%

Radiative and non-radiative decay of selected vibronic levels of the B state of alkoxy radicals

Gopalakrishnan

Miller

2003

Chemical Physics Letters

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Section: Methodsmentioning

confidence: 99%

Radiative and non-radiative decay of selected vibronic levels of the B state of alkoxy radicals

Gopalakrishnan

Miller

2003

Chemical Physics Letters

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“…18,19 In the CO stretch band (see Fig. 9) the rotational transitions appear broader still and some are even split.…”

Section: E Line Broadening and Splittingmentioning

confidence: 97%

“…TheÃ −X separation of the vibrationless levels (T 00 ) of ethoxy was found to be 364 cm −1 in DF spectroscopy 7,16 and 355(10) cm −1 in a photoelectron study. 17 Simulation of the origin band of theB −X LIF transition with rotational and fine-structure resolution was found to require a perpendicular transition type, 18 which implies that the ground electronic state is of A symmetry. Later studies of the DF 7 and high-resolution LIF spectra 19 of 1-propoxy (1-C 3 H 7 O) and other larger primary alkoxies have shown that all of the conformers with C s symmetry (T-conformers) have ground electron states with A symmetry andÃ −X separations of 350 cm −1 .…”

Section: Introductionmentioning

confidence: 99%

Rotationally resolved ${\tilde{B}} \leftarrow {\tilde{X}}$B̃←X̃ electronic spectra of the isopropoxy radical: A comparative study

Liu

Melnik

Miller

2013

The Journal of Chemical Physics

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112

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The B̃-X̃ laser-induced-fluorescence spectrum of jet-cooled isopropoxy radical (i-C3H7O[middle dot]) has been recorded. Using an isolated state model the observed rotational and fine structure of the origin band has been well simulated to determine rotational constants for both the X̃ and B̃ states and the electron spin-rotation constants of the X̃ state. The line intensities are well simulated with a parallel transition type, requiring the same symmetry for the levels involved of each the X̃ and B̃ state, which confirms the previous suggestion that going from ethoxy (C2H5O[middle dot]) to isopropoxy, the energy ordering of the electron configurations with in- and out-of-plane half-filled p-orbitals of the oxygen atom is reversed and the ground vibronic symmetry changes from a" to a'. However, the observed spin-rotation coupling constants are not consistent with their predication from either semi-empirical theory or quantum chemical calculations. Additionally, the lack of observed transitions involving the out-of-plane transition moment component is not consistent with high level electronic structure calculations suggesting mixing of vibronic levels by strong spin-orbit coupling. A new twofold model has been developed that explicitly includes Coriolis and spin-orbit coupling between different vibronic levels. This model renders the discrepancy between theoretical and experimental spin-rotation constants moot. Moreover, it determines independently the contributions to the observed splitting between the lowest two levels, resulting from non-relativistic kinetic and Coulombic effects, and that due to the relativistic spin-orbit interaction. The experimental values show that these effects are comparable, but that the vibronic one is slightly more important. This result is at variance with state-of-the-art electronic structure calculations which otherwise do a remarkably good job of describing the ground state of isopropoxy.

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“…The matrix elements of the rotational Hamiltonian, H Rot , are well-known. 29,30 The spin-rotation Hamiltonian has been examined by many authors 29,[31][32][33][34][35] and can be written as…”

Section: Theorymentioning

confidence: 99%

High-resolution cavity ringdown spectroscopy of the jet-cooled ethyl peroxy radical C2H5O2

Just

Rupper

Miller

et al. 2009

The Journal of Chemical Physics

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We have recorded high resolution, partially rotationally resolved, jet-cooled cavity ringdown spectra of the origin band of the A-X electronic transition of both the G and T conformers of the perproteo and perdeutero isotopologues of the ethyl peroxy radical, C(2)H(5)O(2). This transition, located in the near infrared, was studied using a narrow band laser source (< or approximately 250 MHz) and a supersonic slit-jet expansion coupled with an electric discharge allowing us to obtain rotational temperatures of about 15 K. All four spectra have been successfully simulated using an evolutionary algorithm approach with a Hamiltonian including rotational and spin-rotational terms. Excellent agreement with the experimental spectra was obtained by fitting seven molecular parameters in each ground and the first excited electronic states as well as the band origin of the electronic transition. This analysis unambiguously confirms the assignment of the lower frequency origin band to the G conformer and the higher frequency one to the T conformer.

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Rotationally resolved electronic excitation spectra of the ethoxy ~B .rarw. ~X transition

Cited by 50 publications

References 9 publications

Radiative and non-radiative decay of selected vibronic levels of the B state of alkoxy radicals

Radiative and non-radiative decay of selected vibronic levels of the B state of alkoxy radicals

Rotationally resolved ${\tilde{B}} \leftarrow {\tilde{X}}$B̃←X̃ electronic spectra of the isopropoxy radical: A comparative study

High-resolution cavity ringdown spectroscopy of the jet-cooled ethyl peroxy radical C2H5O2

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