Analysis of products from breakdown of liquid benzene, toluene and cyclohexane caused by Nd3+: YAG pulsed laser irradiation

Products from liquid benzene, toluene and cyclohexane breakdown caused by s trong Nd3+:YAG fundamental pulsed laser irradiation were analyzed. Under na nosecond laser irradiation, hydrogen, methane, acetylene, ethylene, bipheny l, phenanthrene, anthracene and amorphous carbon were detected from Liquid benzene and the laser intensity dependence of their yield was investigated. From laser intensity dependence of absolute quantity, it is suggested that biphenyl is produced by simple mechanism, while anthracene and phenanthren e are produced by diffusional collision of some kind of radicals via multi step reaction. In picosecond laser irradiation, the kind;of products is sam e as those in nanosecond laser irradiation for liquid benzene, however yiel ds of the products were higher because of stronger electric field. While in toluene and in cyclohexane same gaseous products as in benzene were detect ed. In particular, ethane was detected only from cyclohexane. In ultrasonic irradiation that is known as high pressure and high temperature reaction i nto liquid benzene and liquid toluene, results were different from those of laser irradiation. We could conclude that the reaction caused by near-infr ared laser-induced breakdown is basically different from the reaction induc ed by high pressure and high temperature. (C) 2001 Elsevier Science B.V. Al l rights reserved.