Spectroscopy of the CH3Zn radical. Vibrational frequencies and electronic configurations of the X̃, Ã, and C̃ states

✍ Scribed by Robert L. Jackson

• Publisher: Elsevier Science
• Year: 1990
• Tongue: English
• Weight: 636 KB
• Volume: 174
• Category: Article
• ISSN: 0009-2614
• DOI: 10.1016/0009-2614(90)85325-7

✦ Synopsis

The monoalkyl zinc radical, CHJn, may be observed by laser-induced fluorescence following UV photodissociation of ( CH3)2Zn.

The fluorescence spectrum obtained upon excitation of the 08 and the 2: bands of the A-2 transition was assigned. A very simple fluorescence spectrum is obtained upon excitation of the @ band, allowing assignment of the fundamental vibrational frequencies for the C-Zn stretching mode (v,, 445 cm-') and the CH3 umbrella mode (Ye, 1060 cm-') of the 2 state. A much more complicated, time-dependent and pressure-dependent fluorescence spectrum is obtained upon excitation of the 2b band. Collisionally induced energy redistribution within the 2 state during its radiative lifetime populates v= 1 of uj and the upper spin-orbit level of the A state. Observation of fluorescence from these levels allows assignment ofv3 (545 cm-') and the spin-orbit splitting (255 cm-') of the A state. The symmetry species and electronic configurations of the g and A states are assigned by comparison to the analogous states of ZnH. A similar comparison allows assignment of a set of higher energy bands observed by Young, Gosavi, Connor, Strausz and Gunning to the c-2 transition of CH3Zn. The &% transition has not been observed due to very poor Franck-Condon overlap between the B and 2 vibrational states.