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Internet Electronic Journal of Molecular Design - IEJMD, ISSN 1538-6414, CODEN IEJMAT
| ABSTRACT - Internet Electron. J. Mol. Des. September 2006, Volume 5, Number 9, 479-487 |
QSPR Analysis of Solvent Effects on the Decay of the
1Δg State of Molecular Oxygen
Paul G. Seybold
Internet Electron. J. Mol. Des. 2006, 5, 479-487
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Abstract:
Molecular oxygen, O2, commonly exists as a triplet
(3Σg-) ground state, but
also has two excited singlet states,
1&Deltag and 1Σg+,
that are of considerable
interest due to their biological activities and their possible roles in
atmospheric chemistry. In particular, the decay of the
1&Deltag state has been
extensively studied under different conditions and its lifetime is found to
vary widely in different solvents. This solvent dependence has been
attributed to the involvement of solvent vibrational energy-accepting
modes. In the present work a systematic QSPR study of the
1&Deltag state decay
in 54 solvents is presented and observations are made about the factors
influencing the decay. Multiple linear regressions were performed using
the SAS statistical program. A high-quality statistical model with five
variables and R2 = 0.993
was obtained for the nonradiative decay rate
constant. Only five solvent features contribute significantly to the
nonradiative decay rate of the 1&Deltag state.
Four of these features can be
associated with solvent oscillators, and the fifth, previously not well
identified, with an external spin-orbit effect. Some solvent data are
questionable, and further studies of particular features are recommended.
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