Dispersed Fluorescence Spectroscopy of Jet-Cooled Isobutoxy and 2-Methyl-1-butoxy Radicals

作者：Reza Md Asmaul; Paul Anam C; Reilly Neil J; Alam Jahangir; Liu Jinjun^*

来源：Journal of Physical Chemistry A, 2016, 120(34): 6761-6767.

DOI：10.1021/acs.jpca.6b06445

We report dispersed fluorescence (DF) spectra of the iso-butoxy and 2-methyl-1-butoxy radicals produced by photolysis of corresponding nitrites in supersonic jet expansion. Different vibrational structures have been observed in the DF spectra when different vibronic bands in the laser-induced fluorescence (LW) spectra of each radical Were pumped, which suggests that those vibronic bands be assigned to different conformers. Spectra simulated using calculated vibrational frequencies and Franck Condon factors well reproduce the experimentally observed ones and support the assignment of the vibronic bands in the LIF spectra to the two lowest-energy conformers of each radical. DF spectra obtained by pumping the (B) over tilde <- (X) over tilde origin bands of the LIT spectra are dominated by CO stretch progresSions because of the large difference in CO bond length between the ground ((X) over tilde) and the second excited ((X) over tilde) electronic states. Furthermore, with non-CO stretch-bands pumped, the DF spectra are dominated by progressions of combination bands, of the CO stretch and the pumped modes as a result of Duschinsky mixing. (A) over tilde-(X) over tilde separation of both conformers of the isobutoxy radical has also been determined in the experiment.

• 出版日期2016-9-1