Investigation of six-membered carbocyclic compounds as a molecular switch block of room temperature phosphorescence in nondeoxygenated β-cyclodextrin solution

An aerated aqueous solution, intense room temperature phosphorescence (RTP) of nitrogen heterocyclic compounds (NHCs) and polyaromatic hydrocarbons (PAHs) can be observed when micro amounts of six-membered carbocyclic compounds (6-MCCs) are introduced in β-cyclodextrin (β-CD) solution. In order to find the predominating factors of the enhanced phosphorescence observed with this novel approach, 22 typical phosphors of NHCs and PAHs were carefully screened and served as model compounds. The role of the inner heavy atom, the substituent group and the host-guest molecules space-matching on the RTP of different phosphors were investigated. The results demonstrated that the enhancement effects of cyclohexane, bromocyclohexane and cyclohexanol for the RTP of NHCs and PAHs have precedence over traditional halide alkanes such as 1,2-dibromoethane (DBE), exhibiting an obvious sequence as following: cyclohexane > bromocyclohexane > cyclohexanol. This new approach compared with other RTP methods is simple, convenient and fast.