Investigation of spectroscopic behaviors of newly synthesized (2E)-3-(3,4-dimethoxyphenyl)-1-(2,5-dimethylthiophen-3-yl)prop-2-en-1-one (DDTP) dye.

This study introduced spectroscopic properties, physicochemical parameters, and polarity and photostability behaviors of a newly prepared chalcone dye. The chalcone dye, (2E)-3-(3,4-Dimethoxyphenyl)-1-(2,5-dimethylthiophen-3-yl)prop-2-en-1-one (DDTP), was synthesized by the reaction of 3,4-dimethoxybenzaldehyde with 3-acetyl-2,5-dimethythiophene. Results of FT-IR, (1)H-NMR, (13)C-NMR and elemental analysis were in conformity with chemical structure of newly prepared DDTP. Data of thermal gravimetric analysis revealed that DDTP has good thermal stability. Increases in fluorescence intensities of DDTP with cetyltrimethyl ammonium bromide (CTAB) were observed. In comparison of fluorescence intensities for DDTP with CTAB, reductions in fluorescence intensities for DDTP with sodium dodecyl sulphate (SDS) were observed under the same experimental and instrumental conditions. Moreover, Benesi-Hildebrand method was applied to determine stoichiometric ratios and association constants of DDTP with CTAB and SDS. The stoichiometric ratio and association constant obtained from Stern-Volmer plot strongly supported those obtained from Benesi-Hildebrand plot of DDTP with SDS. Physicochemical parameters, such as, singlet absorption, molar absorptivity, oscillator strength, dipole moment and fluorescence quantum yield of DDTP were also estimated. Fluorescence steady-state measurements ultimately displayed that DDTP has a high photostability against photobleaching. Fluorescence polarity study revealed that DDTP was sensitive to the polarity of the microenvironment provided by different solvents.