Fluorescence and room temperature phosphorescence of 6-bromo-2-naphthol in beta-cyclodextrin solution and its selective molecular recognition for cyclohexane

摘要

The room temperature phosphorescence (RTP) and fluorescence behavior of 6-bromo-2-naphthol (BN) in water and beta-cyclodextrin (beta-CD) aerated aqueous solution was investigated.The study of fluorescence behavior at different pH values indicated that three kind of species of BN (protonated,uncharged and anionic species) formed 1:1 inclusion complexes with beta-CD,and RTP and fluorescence emission depended on the pH of the solution.The inclusion complex constants were 430+-251 mol~(-1) (pH1.80),840+-251 mol~(-1) (pH5.80),1850+-751 mol~(-1) (pH 11.50),respectively.Experimental results elucidated that RTP of the BN/beta-CD/cyclohexane solution came from the protonate and uncharged species of BN,but not from the anionic species,through the inclusion constant of the anionic species of BN with beta-CD was larger than that of the other two species of BN Selective molecular recognition of BN/beta-CD as an RTP sensor for 28 small organic molecules was studied,it was shown that BN/beta-CD could be develop as a new RTP sensor with high selectivity molecular recognition ability for cyclohexane.