DEVELOPMENTAL RESEARCH ON LASER-INDUCED SYNTHETIC REACTIONS

激光诱导反应有望应用于工业合成过程，特别是高选择性地生产某种特定化学品。然而，重要的问题是高激光光子成本。本研究旨在发展某些连锁反应。本文研究了1，1-二氯乙烷经氯化、脱氯化氢反应合成偏氯乙烯的过程和环己烷部分氧化反应的过程，前者是在氯气存在下，用XeF准分子激光器辐照1，1-二氯乙烷开始反应。光解离的氯原子起到链载体的作用，生成长链的1，1，1-三氯乙烷。在随后的步骤中，三氯乙烷以相对高的链长脱氯化氢以产生偏二氯乙烯。因此，将上述两步反应结合起来，建立了一种新的偏二氯乙烯合成工艺。环己烷与溶解氧的液相吸收KrF准分子激光和激光诱导的氧化反应进行生成环己醇和环己酮。但是，该体系中的反应过程受溶剂笼中自由基-自由基反应的控制，链长不够长，一般来说，在许多反应体系中，链长可以被拉长到足够大的程度，因此激光诱导的反应可以应用于实际体系中.预计未来将开发许多反应系统。

Laser induced reactions are expected to be adopted in industrial synthetic processes, particularly for producing a certain kind of specific chemicals with a high selectivity. However, the important concern is the high laser-photon cost. The present research aims at the development of certain chain reactions. The synthetic process of vinylidene chloride from 1,1-dichloroethane through a chlorination followed by a dehydrochlorination reaction, and the partial oxidation process of cyclohexane have been studied.In the former system, the reaction was started by irradiation of 1,1-dichloroethane in the presence of chlorine with a XeF excimer laser. The photo-dissociated atomic chlorine playd as a chain-charrier, and 1,1,1-trichloroethane was produced with a long chain length. In the subsequent step, the trichloroethane was dehydrochlorinated with a relatively high chain length to yield vinylidene chloride. Thus by combining the above two steps, a novel synthetic process of vinylidene chloride was established.Concerning the partial oxidation of cyclohexane, the following results were obtained. The liquid phase cyclohexane with dissolved oxygen absorbed the KrF excimer laser light and the laser-induced oxidation reaction proceeded to yield cyclohexanol and cyclohexanone. However, the reaction progress in the present system was controlled by radical-radical reactions in the solvent cage, and thus the chain length was not sufficiently long.Generally speaking, the chain length could be elongated to a high enough extent in many reaction systems, so that the laser-induced reactions may be adopted in practical systems. Many reaction systems are expected to be developed in future.