碘鎓盐/胺光引发聚合体系的初级反应研究

碘鎓盐/胺复合体系,用作自由基光敏聚合的引发剂具有良好的效果,但是关于碘鎓盐和胺相互作用产生有引发活性的自由基的光化学反应机制尚不清楚。Ptitsyna曾研究了二苯基碘鎓盐和三苯基膦的光化学反应,认为首先发生鎓盐的裂解反应,接着进行芳基化作用,生成主要产物四苯基鏻和碘苯。而二芳基碘鎓盐和脂肪胺的热化学反应,则得到的主要胺类产物为原始胺的盐,芳基化产物很少。 本工作以二苯基碘鎓盐(DPIOC)/三乙胺(TEA)为例子,研究了这类化合物的光化学反应。采用高压汞灯为光源,并滤去<300nm的光,介质为CH_3CN/H_2O(14:1,V/V)混合溶剂,反应在N_2下进行,温度为30℃。关于碘鎓盐和叔胺分子间的相互作用,从

STUDY ON THE PRIMARY REACTIONS OF IODONIUM SALT/AMINE COMBINATION PHOTOINITIATION SYSTEM

The primary reaction of iodonium salt/amine combination initiation system was studied. From the experimental results, the following reaction mechanism is proposed. The charge transfer complexes between iodonium salt and amine in the ground state(CTC) and in the excited state (exciplex) occur in the polar solution, and under irradiation, this combination system undergoes electron transfer process to produceamine radical cation (-N+) and diphenyliodine radical (Ph2I), the latter can furthercleavage to iodobenzene and phenyl radical (Ph). These radical and radical cation species formed result in a vinyl polymerization. These reaction processes were proved by means of IR, 1HNMR, GC-MS spectra and elementary analysis.