IR and UV photolysis of 1,3-cyclohexadiene. Evidence for formation of vibrationally excited 1,3,5-hexatriene

✍ Scribed by Awadhesh Kumar; P.K. Chowdhury; K.V.S. Rama Rao; J.P. Mittal

• Publisher: Elsevier Science
• Year: 1993
• Tongue: English
• Weight: 536 KB
• Volume: 212
• Category: Article
• ISSN: 0009-2614
• DOI: 10.1016/0009-2614(93)87115-j

✦ Synopsis

The KrF and SF,-sensitized CO2 laser-induced photodissociation of 1,3-cyclohexadiene produce the same major products -cisand trans-1,3$hexatriene (HT), benzene and H,, with relative yields strongly dependent on the source of excitation and the substrate pressure. From the time evolution of the nascent products, the rate constant for dissociation of 1 ,f-cyclohexadiene is estimated to be z 4x 10' and 8x IO5 s-l, respectively, in LTV and IR photolysis. The UV absorption spectrum of the transient HT with a red-shift of about 30 nm implies the formation of vibrationally hot HT. The vibrational temperature of the system is estimated from the relative yields of cir and trans-HT. The benzene channel is suggested as originating from a relatively higher vibrational level than the HT channel.