Rotationally Resolved ~b ← ~x Electronic Spectra of the Iso-Propoxy Radical and Other Secondary Alkoxy Radicals

Other

Scientific paper

Rate now

  [ 0.00 ] – not rated yet Voters 0   Comments 0

Details

Electronic (Uv/Vis/Nir)

Scientific paper

The B - X laser-induced-fluorescence (LIF) spectrum of jet-cooled iso-propoxy radical (i-C_3H_7O\cdot) has been recorded. The observed rotational and fine structure of the origin band has been well simulated with rotational constants for both the X and B states and the electron spin-rotation constants of the X state. The line intensities are well simulated with a parallel transition type, requiring the same symmetry for the X as for the B state (A ^'), which confirms the previous suggestion S. C. Foster and T. A. Miller, J. Phys. Chem. 93, 5986 (1989).} that going from ethoxy (C_2H_5O\cdot) to iso-propoxy, the energy ordering of the in- and the out-of-plane half-filled p-orbitals is reversed and the ground state symmetry changes from A^" to A^'. The fit rotational constants are consistent with those obtained from the quantum chemistry calculations. However, the fit spin-rotation constants, particularly the nonzero epsilonaa with a-axis perpendicular to the C_s plane, can not be explained by second-order perturbation theory. Nevertheless they can be semi-quantitatively explained based on the transferability of the electron spin-molecular rotation tensor. in the axis system defined by the half-filled p-orbital and the pπ-orbital using ethoxy as the reference molecule. The failure of the second-order perturbation theory, as well as that of the pure precession approximation, is due to the strong vibronic interaction between the near-degenerate X and A states. The vibrationless levels of these two states are separated by only 68 cm-1 as determined in previous disperse-fluorescence study. The near degeneracy of the X and A states of iso-propoxy and reversal of the energy ordering going from ethoxy to iso-propoxy have also been demonstrated in quantum chemistry calculations. Based on the result of iso-propoxy, spin-rotation constants of other secondary alkoxy radicals can be predicted and used for the simulation of the B - X rovibronic spectra of these radicals. Specifically, analysis of the high-resolution LIF spectrum of cyclohexoxy (c-C_6H11O\cdot) is ongoing.
G. Tarczay, S. Gopalakrishnan, and T. A. Miller, J. Mol. Spectrosc. 220, 276 (2003).
J. Jin, I. Sioutis, G. Tarczay, S. Gopalakrishnan, A. Bezant, and T. A. Miller, J. Chem. Phys. 121, 11780 (2004).
L. Zu, J. Liu, G. Tarczay, P. Dupre, and T. A. Miller, J. Chem. Phys. 120, 10579 (2004).

No associations

LandOfFree

Say what you really think

Search LandOfFree.com for scientists and scientific papers. Rate them and share your experience with other people.

Rating

Rotationally Resolved ~b ← ~x Electronic Spectra of the Iso-Propoxy Radical and Other Secondary Alkoxy Radicals does not yet have a rating. At this time, there are no reviews or comments for this scientific paper.

If you have personal experience with Rotationally Resolved ~b ← ~x Electronic Spectra of the Iso-Propoxy Radical and Other Secondary Alkoxy Radicals, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Rotationally Resolved ~b ← ~x Electronic Spectra of the Iso-Propoxy Radical and Other Secondary Alkoxy Radicals will most certainly appreciate the feedback.

Rate now

     

Profile ID: LFWR-SCP-O-1593606

  Search
All data on this website is collected from public sources. Our data reflects the most accurate information available at the time of publication.