| Summary: | 碩士 === 國立臺灣大學 === 化學系研究所 === 86 === We have investigate the room temperature phosphorescence(RTP) of phosphors
in β-cyclodextrin(β-CD) bearing a heavy-atom containing side chain.Two β-CD
derivatives were synthesized by replacing the primary hydroxyls with 2-bromoe
thylamino or 3-bromopropylamino group. In aqueous solution, these β-CD deri
vatives form 1:1 inclusion complex with phosphors. The presence of a side chai
n on β-CD increases the formation constants of the complex significantly. For
example, the formation constants of acenaphthene with β-CD and 2-bromoethyla
mino-β-CD were determined to be 76 and 402 1/M, respectively. The formation o
f inclusion complex were accompanied by decreases in enthalpy and entropy. App
reciable RTP was observed when the phosphor in included in the cyclodextrin ca
vity and within the realm of influence of heavy atoms. More intense and stable
RTP was detected in 3-bromopropylamino-β-CD than in 2-bromoethylamino-β-CD
system. The size and polarity of phosphors are also important in the detection
of RTP. The optimal pH for RTP detection is pH 5~6.
Removal of dissolved o
xygen is essential for successful detection of RTP. Several deoxygenation tech
niques including nitrogen purging, sodium sulfite, Zn/HCl, or sodium carbonate
/HCl have been compared. Deoxygenation by sodium sulfite was found to be the m
ost efficient method.
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