The effect of cyclodextrin complexation on the fluorescence properties of ethyl-4′-dimethylaminobenzoate

The effect of cyclodextrin (CD) complexation on the fluorescence properties of ethyl-4′-dimethylaminobenzoate (EDMAB) was studied. The complex exhibited dual fluorescence whereas no TICT fluorescence was observed in aqueous solution without α-CD. At lower concentrations of α-CD, the TICT emission was centered at 520 nm and the addition of α-CD resulted in the emergence of new TICT emission band at ∼450 nm. The dependence of TICT emission intensity on pH and α-CD concentration suggested that a 1:2 EDMAB–α-CD complex was responsible for the TICT emission at 450 nm whereas a 1:1 complex has the emission band at 520 nm.