醇对环糊精/溴代萘超分子组合体系室温燐光的影响

Effects of Alcohols on Room Temperature Phosphorescence of Cyclodextrin /α-Bromonaphthalene Supramolecular Assembly Systems

研究了ＣＤ／溴化萘／醇体系的室温燐光发射条件、发光特性和不同醇、不同ＣＤ的影响。认为就本质而言，这类发光体系属一种超分子组合体系。其中，ＣＤ与内含重原子的发光体借助于分子间作用力形成二元包结物；而醇则与ＣＤ端口的羟基形成氢键，其烷基链借助于疏水作用力覆盖在ＣＤ的端口，如同一种疏密不同的盖子，不仅提高了ＣＤ腔内的疏水性，增大了发光体与ＣＤ的结合常数，同时，对外部氧向ＣＤ腔内的扩散起着隔离作用，其效应如同通Ｎ２除氧过程，从而可在不除氧条件下，观察到强的室温磷光发射。由于这类流体室温■光现象，在属性上已超出原有环糊精诱导室温■光范畴，醇的作用属超分子化学中典型的分子调控作用，其主体理应不局限于环糊精，因此建议将其命名为超分子组合室温■光（Ｓｕｐｒａｍｏｌｅｃｕｌａｒ Ａｓｓｅｍｂｌｙ ＲｏｏｍＴｅｍｐｅｒａｔｕｒｅＰｈｏｓｐｈｏｒｅｓｃｅｎｃｅ，简写为 ＳＭ－ＲＴＰ）。

The fluid room temperature phosphorescence (RTP) properties of P-cyclodextrin (P-CD)/a-bromonaphthalene/t-butanol system have been studied. It is observed that the system can give intense RTP signal without deoxygenation. The effects of different alcohols and CDs are compared. The experimental results suggest that the alcohol bond to the rim of the CD cavity, through hydrogen bonding between alcohol hydroxyl and CD hydroxyl, and the aliphatic chains of the alcohol cover the top and bottom of CD cavity by hydrophobic in- teraction. The alcohol acts as a lid for the CD cavity, thereby shielding luminophor from oxygen and preventing RTP from quenching. To our knowledge, this type of luminescence system belongs essentially to a kind of supramolecular assembly system. So it is proposed to use th name Supramolecular Assembly Room Temperature Phosphorescence (SM-RTP) for this type of RTP emission.