Synthesis and spectroscopic investigation of a novel solvatochromic dye

Optical response of a novel dye has been studied in various media like neat and mixed binary solvents, aqueous SDS micelles and β-cyclodextrin (β-CD) nanocavities. Fluorescence parameters in pure and mixed binary solvents have been found to be sensitive to the nature of the microenvironment. The emitting state of the dye in protic solvent is different from that in aprotic solvents. In presence of cations (H+, Mg2+), the dye exists in two tautomeric forms at equilibrium in solution. The values of the equilibrium constant (K) and ΔH0 have been measured. Values of local dielectric constant (ε) and microviscosity (η) at the region of solubilisation of the dye in aqueous SDS micellar media have been found out. The dye has also been found to form complex with β-CD. The equilibrium constant and the energy of maximum fluorescence of the dye encapsulated by β-CD have been determined.