External electric field effects on photochemical dynamics

将咔唑、芘或菲与对苯二甲酸甲酯或二甲基苯胺组成的亚甲基化合物掺杂到聚合物薄膜中，测量了电致荧光光谱，以考察电场对光致电子转移、反电子转移和充电复合过程的影响。以草酸和花生酸组成的混合LB膜为电子给体，紫精和花生酸组成的混合LB膜为受体，制备了具有一定方向的层间光致电子转移的多层膜。用不同的脂肪酸间隔层考察了电场对这些LB膜的吸收光谱和荧光光谱的影响，考察了电场对光诱导电子转移过程的影响及其给体-受体距离的依赖关系。研究发现，外加电场可以很好地影响芘及其偶联化合物的准分子荧光。与分子随机分布在薄膜中的情况相比，吡喃分子键合化合物的准分子荧光的场依赖性要大得多。结果表明，芘分子的有效场依赖关系与其有效的电致发光密切相关。用咔唑和对苯二甲酸甲酯组成的偶联化合物考察了电场对荧光衰变曲线的影响。

Methylene-linked compounds composed of carbazole, pyrene or phenanthrene and terephthalic acid metyl ester or dimethyl aniline are doped in a polymer film, and electrofluorescence spectra have been measured in order to examine the field effects on initial step of photoinduced electron transfer, back electron transfer and charger recombination processes. Multi-stacking layer films where interlayer photoinduced electron transfer occurs with a definite direction have been also prepared using mixed LB monolayer composed of oxacarbocyanine and arachidic acid as an electron donor and mixed LB monolayer composed of viologen and arachidic acid as an acceptor. Electric field effects on absorption spectra as well as on nuorescence spectra of these LB films have been examined with different spacer layers of fatty acid between oxacarbocyanine and viologen layers to examine the field effects on photoinduced electron transfer process and its donor-acceptor distance dependence. Excimer fluorescence of pyrene and pyrene linked compounds is found to be well affected by an electric field. The field dependence of the excimer fluorescence of the linked compounds of pyrene is much larger than that where pyrene molecules are distributed in a film randomly. The efficient field dependence of the excimer fluorescence of pyrene is found to be closely related to the efficient generation of elelctroluminescence. Electric field effects on fluorescence decay profile were also examined using the linked compounds composed of carbazole and terephhtalic acid methyl ester.