Room-temperature phosphorescence properties from cyclodextrin inclusion complexes in solutions

在室温下，芳香化合物在溶液中发出的磷光通常不能被观察到。然而，室温磷光（RTP）从客体，它位于环糊精（CD）包合物，是经常观察到的。到目前为止，除了α -CD- 6-溴-2-萘酚和α -CD-2-氯萘包合物外，β -和γ -CD（衍生物）被称为CD包合物，它们发射RTP。在-CD和-CD的情况下，包含单个CD分子的包合物会发出客体的RTP。另一方面，对于alpha-CD，仅2:1 a- cd -guest包含复合体就会发出RTP。因此，我们检查了来宾是否在溶液中含有a-CD的包合物中释放RTP。结果发现- cd -3-溴喹啉包合物在溶液中释放RTP，在- cd -3-溴喹啉体系中，确定了1:1和2:1的- cd -3-溴喹啉包合物。测定了包合物的形成常数。合成了碘取代cd，研究了溴化cd -3-溴喹啉包合物的RTP性质。溴化cd包合物的RTP比环糊精降低了约18%。在含d -葡萄糖的溶液中观察了β - cd -萘包合物的RTP；RTP的量子产率为0.0022。

At room temperature, phosphorescence from aromatic compounds in solutions cannot be usually observed. However, room-temperature phosphorescence (RTP) from a guest, which is located within a cyclodextrin (CD) inclusion complex, is frequently observed. Until now, beta- and gamma-CDs (derivatives) are known as CD inclusion complexes which emit RTP, except for alpha- CD-6-bromo-2-naphthol and alpha-CD-2-chloronaphthalene inclusion complexes. In the cases of beta- and gamma-CDs, an inclusion complex which contains a single CD molecule emits the RTP of a guest. With alpha-CD, on the other hand, a 2 : 1 a-CD-guest inclusion complex alone emits the RTP.Thus, we examined whether guests emit RTP within inclusion complexes with a-CD in solutions. As a result, we found that alpha-CD-3-bromoquinoline inclusion complex emit the RTP in solution, In the system of alpha-CD-3-bromoquinoline, a 1 : 1 and 2 : 1 alpha-CD-3-bromoquinoline inclusion complexes are confirmed. The formation constants for the inclusion complexes were determined.Iodine-substituted alpha-CD was synthesized to investigate the properties of the RTP of the brominated-alpha-CD-3-bromoquinoline inclusion complex. The RTP of brominated-alpha-CD inclusion complex is reduced about 18% compared to alpha-cyclodextrin. The RTP from beta-CD-naphthalene inclusion complex was observed in solution containing D-glucose ; the RTP quantum yield was evaluated to be 0.0022.