A new complete basis set model (CBS-QB3) study on the possible intermediates in chemiluminescence
| Autor: | Xiao-Zeng You, Yong Zhang, Xi-Rui Zeng |
|---|---|
| Rok vydání: | 2000 |
| Předmět: |
General Physics and Astronomy
State (functional analysis) law.invention chemistry.chemical_compound chemistry Chemical physics law Computational chemistry Potential energy surface Singlet state Complete active space Physics::Chemical Physics Physical and Theoretical Chemistry Triplet state Basis set Carbon monoxide Chemiluminescence |
| Zdroj: | The Journal of Chemical Physics. 113:7731-7734 |
| ISSN: | 1089-7690 0021-9606 |
| Popis: | The new highly accurate complete basis set model, CBS-QB3, was employed here to elucidate the long experimentally discussed problem in a general class of chemiluminescent reactions involving peroxyoxalate systems. Both the stability comparison and the vibrational spectra favor that the intermediate is better to be recognized as the cyclic singlet 1,2-dioxetanedione with the C2v symmetry, which verifies the experimental suggestion yet provides more characterization information. Another two kinds of minimum species in its potential energy surface (PES) are two kinds of product: (1) two carbon dioxide and (2) two carbon monoxide and one oxygen, where the thermodynamic parameters correctly identify their relative yield in the experiment—the former is much more abundant than the latter. In a complete search of minimum states in its PES, the triplet C2v and D2h states were found, which is energetically unfavorable compared with the singlet C2v state. Their vibrational data also support some experimental conclusions of ruling out a radical intermediate. In contrast, the singlet D2h state was found to be a transition state for the “up” and “down” singlet C2v states. The complete active space self-consistent-field calculations with the second-order Moller–Plesset correlation energy correction also support that the most stable species is the singlet C2v state and the singlet D2h state is more energetically favorable than its triplet counterpart. |
| Databáze: | OpenAIRE |
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