Room temperature phosphorescence of α-bromonaphthalene induced by cyclodextrin in the presence of hexahydropyridine or 1-ethylpiperidine and its application

Two novel heterocyclic third components, hexahydropyridine (HHP) and 1-ethylpiperidine (EP) were firstly found to enhance room temperature phosphorescence (RTP) of α-bromonaphthalene (α-BrN) induced by cyclodextrin. The effects of equilibrium time for formation of inclusion complex, temperature, pH values and the variation of concentrations of each component on RTP of α-BrN and the RTP lifetime of each ternary complex had been investigated and compared to discuss inclusion mechanism of ternary complexes. The RTP lifetimes of α-BrN/β-CD/HHP, α-BrN/β-CD/cyclohexane (CH) and α-BrN/β-CD/EP were 6.18, 7.71 and 9.36 ms, respectively. Based on the strongest RTP of α-BrN induced by CD in the presence of EP, a method for determination of EP was established. Under the optimal conditions, the analytical curve of EP gave a liner dynamic range of 1.50 × 10−4 to 1.50 × 10−3 mol L−1 with a detection limit of 4.8 × 10−5 mol L−1. When the established CD-RTP method was applied to determine the concentration of EP synthetic samples in distilled water, the experimental results demonstrated that the recovery was 91.4% with a relative standard deviation less than 2.85% (n = 7).