|Budget Amount *help
¥3,000,000 (Direct Cost : ¥3,000,000)
Fiscal Year 1998 : ¥1,100,000 (Direct Cost : ¥1,100,000)
Fiscal Year 1997 : ¥1,900,000 (Direct Cost : ¥1,900,000)
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.