聚电解质对离子型染料形成激基缔合物和能量传递的增强作用

在水溶液中聚苯乙烯磺酸钠(Napss)可以增加离子型染料吖啶橙和吡红的局部浓度,从而显著地促进吖啶橙形成激基缔合物,增大吖啶橙-吡红能量传递效率.在10^-^4mol.dm^-^3Napss存在下,形成吖啶橙激基缔合物的速率常数比Napps不存在时增大两个数量级,而离解常数小一个数量级.表明在聚电解质存在下,两个吖啶橙分子在基态时相互靠近处于液基缔合物的构型.加入小分子电解质可阻止染料形成激基缔合物.

Enhancement of excimer formation and energy transfer efficiency of ionic dyes via interaction with polyelectrolyte

In aqueous solution, Na polystyrenesulfonate (NaPSS) increases the local concentration of ionic dyes Acridine Orange and Pyronine around macroions and enhances excimer formation of Acridine Orange and the efficiency of energy transfer from excited Acridine Orange to Pyronine ground state. In the presence of 10-4 mol dm-3 NaPSS the excimer formation rate constant of Acridine Orange is enhanced by 102 times and the dissociation rate constant of the excimer is decreased 10 times, indicating that excimer, at least in part, is generated from preformed complexes i.e. configurations in which 2 Acridine Orange mols. are in close contact at the instant of absorption. NaCl retards excimer formation of Acridine Orange.