標題: | Photodissociation Dynamics of Benzaldehyde (C6H5CHO) at 266, 248, and 193 nm |
作者: | Bagchi, Arnab Huang, Yu-Hsuan Xu, Z. F. Raghunath, P. Lee, Yuan T. Ni, Chi-Kung Lin, M. C. Lee, Yuan-Pern 應用化學系 應用化學系分子科學碩博班 Department of Applied Chemistry Institute of Molecular science |
關鍵字: | benzaldehyde;computational chemistry;photochemistry;photolysis;time-resolved spectroscopy |
公開日期: | 4-十一月-2011 |
摘要: | The photodissociation of gaseous benzaldehyde (C6H5CHO) at 193, 248, and 266 nm using multimass ion imaging and step-scan time-resolved Fourier-transform infrared emission techniques is investigated. We also characterize the potential energies with the CCSD(T)/6-311+G(3df,2p) method and predict the branching ratios for various channels of dissociation. Upon photolysis at 248 and 266 nm, two major channels for formation of HCO and CO, with relative branching of 0.37:0.63 and 0.20:0.80, respectively, are observed. The C6H5+HCO channel has two components with large and small recoil velocities; the rapid component with average translational energy of approximately 25 kJ mol(-1) dominates. The C6H6+CO channel has a similar distribution of translational energy for these two components. IR emission from internally excited C6H5CHO, nu(3) (nu = 1) of HCO, and levels nu <= 2, J <= 43 of CO are observed; the latter has an average rotational energy of approximately 13 kJ mol(-1) and vibrational energy of approximately 6 kJ mol(-1). Upon photolysis at 193 nm, similar distributions of energy are observed, except that the C6H5+HCO channel becomes the only major channel with a branching ratio of 0.82 +/- 0.10 and an increased proportion of the slow component; IR emission from levels nu(1) (nu = 1) and nu(3) (nu = 1 and 2) of HCO and nu <= 2, J <= 43 of CO are observed; the latter has an average energy similar to that observed in photolysis at 248 nm. The observed product yields at different dissociation energies are compared to statistical-theory predicted results based on the computed singlet and triplet potential-energy surfaces. |
URI: | http://dx.doi.org/10.1002/asia.201100483 http://hdl.handle.net/11536/150417 |
ISSN: | 1861-4728 |
DOI: | 10.1002/asia.201100483 |
期刊: | CHEMISTRY-AN ASIAN JOURNAL |
Volume: | 6 |
起始頁: | 2961 |
結束頁: | 2976 |
顯示於類別: | 期刊論文 |