gür, mahmut kastamonu university - faculty of forestry - department of forest industrial engineering, Kastamonu, Turkey , şener, nesrin kastamonu university - faculty of art and science - department of chemistry, Kastamonu, Turkey

SYNTHESIS AND CHARACTERIZATION OF SOME NEW 1,3,4-THIADIAZOLE COMPOUNDS DERIVED FROM -METHYL CINNAMIC ACID AND THEIR ENERGETICS AND SPECTRAL ANALYSES BASED ON DENSITY FUNCTIONAL THEORY CALCULATIONS

34478

Some novel 1,3,4-thiadiazole compounds derived from α-methyl cinnamic acid was synthesized, in this study. The structures of these compounds were elucidated by using spectroscopic methods such as FT-IR spectroscopy, 1H-NMR spectroscopy, 13C-NMR spectroscopy. Then, the absorption characteristics of the compounds were also examined by using UV-Vis spectrophotometer. In addition, the geometrical and electronic properties as well as Ultraviolet Visible analyzes of the compounds were theoretically done by using the density functional theory. The electronic configurations of the compounds substituted fluoro, chloro and methoxy have been investigated and how to effect chemical reactivity parameters to this configuration have been analyzed by using frontier molecular orbital energies. The calculated values obtained by B3PW91 with 6-311++G basis set and B3LYP with cc-PVTZ basis set are in good agreement with the experimental data. The results show that the UV-Vis absorptions are noticeably influenced by the o-, m- or p- positions of Cl, F and methoxy substituents. The methoxy substituent has more effect on the LUMO energies when compared to the Cl and F substituents. Moreover, positions of the substituents in the isomeric compounds were found to influence the molecular electronegativity and absorption wavelength. The absorption wavelength has the greatest value as the electronegativity of the isomer structures in the p-position of the substituents is smaller.

939

1 , 3 , 4 , thiadiazoles , α , methyl cinnamic acid , Computational chemistry , DFT

Anadolu University Journal of Science and Technology. A : Applied Sciences and Engineering

950