Cavity Ringdown Spectrum of 2-Cyclohexen-1-one in the CO/Alkenyl CC Stretch Region of the S1(n, π*)–S0 Vibronic Band System
| Autor: | Stephen Drucker, Ashley Mooneyham, Michael P. McDonnell |
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| Rok vydání: | 2017 |
| Předmět: |
010304 chemical physics
Absorption spectroscopy Chemistry Spectrum (functional analysis) Conjugated system 010402 general chemistry 01 natural sciences Bond order Molecular physics 0104 chemical sciences Computational chemistry Molecular vibration 0103 physical sciences Molecule Physical and Theoretical Chemistry Excitation |
| Zdroj: | The Journal of Physical Chemistry A. 121:2343-2352 |
| ISSN: | 1520-5215 1089-5639 |
| Popis: | The 2-cyclohexen-1-one (2CHO) molecule serves as a prototype for understanding the photochemical properties of conjugated enones. We have recorded the cavity ringdown (CRD) absorption spectrum of 2CHO vapor at room temperature over the 360–380 nm range. This portion of the spectrum encompasses the S1(n,π*) ← S0 vibronic band system in the region of the C═C and C═O stretch fundamentals. We have assigned about 40 vibronically resolved features in the spectrum, affording fundamental frequencies for 7 different vibrational modes in the S1(n,π*) state, including the C═C (1554 cm–1) and OC—CH (1449 cm–1) stretch modes. The C═O stretch character is spread over at least four different vibrational modes in the S1(n,π*) state, with fundamentals spanning the 1340–1430 cm–1 interval. This finding stems from a significant reduction in C═O bond order upon excitation, which leads to near-coincidence of the C═O stretch and several CH2 wag frequencies. Such complexities make 2CHO an ideal candidate for testing excited-sta... |
| Databáze: | OpenAIRE |
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