疏水作用对光化学和光物理过程的影响——Ⅸ.长链分子的簇集对β-萘甲酸烷基酯和脂肪酸9-蒽甲醇酯间能量传递的增强作用

Hydrophobic Effects on Photochemical and Photophysical Processes——Ⅸ. Enhancement of Singlet-Singlet Energy Transfer from Alkyl 2-Naphthoates to 9-Anthracenemethyl n-Alkanoates via Aggregation

在二甲基亚砜-水(DMS0-H_2O)混合溶剂中,长链β-萘甲酸烷基酯(A_n)、长链脂肪酸9-蒽甲醇醣(E_n)和长链饱和烷烃(C_n)相互簇集形成共簇集体,A_n通过共振机制向E_n进行单重态能量传递。在每个簇集体含近一个给体分子和一个受体分子的情况下,能量传递效率高达50％。簇集体内能量传递的速度比簇集体间的大一个数量级。A_n激基缔合物也可向E_n进行能量传递,但效率很低。由于形成激基缔合物的过程与能量传递过程相互竞争,激基缔合物的形成降低了能量传递的效率。

In dimethyl sulfoxide-water (DMS0-H_2O) so(?)vent mixture long chainhydrocarbons (C_n), alkyl 2-naphthoates (A_n) and 9-anthracenemethyl n-alkanoates (E_n) associate into co-aggregates. The singlet-singlet energy transfer from A_n to E_n occurs via dipole-dipole interaction in the co-aggregates. Under the condition that each co-aggregate contains one A_n and one E_n molecules, the efficiency of energy transfer is as high as 50％. The rate of intra aggregative energy transfer is one order in magnitude higher than that of interaggregative energy transfer. Energy transfer from A_n excimer to E_n was also observed, but the efficiency is very low. As a result, excimer rmatoin decreases the efficiency of energy transfer since it competes with the energy transfer from A_n monomer.