Theoretical study on structure, spectrum and thermodynamic properties of 2, 5-bis (4-Bromomethyl)-1, 3, 4-oxadiazole

The geometry structures, spectra and thermodynamic properties of 2, 5-Bis (4-Bromomethyl)-1, 3, 4-oxadiazole molecule were studied at B3LYP/6-31+G^* level by using density functional theory. The results show that three rings of the optimized structure were in the same plane, and two Bromine atoms were located on both sides of the plane respectively. In gas, absorption wavelength of the strongest energy excitation was obtained at 315 nm, which caused by s₀ to s₁ electronic warp; solvents made it red-shifted 4∼6 nm. According to the thermodynamic calculation, the standard molar enthalpy, standard molar heat capacity and standard Moore entropy are all have good quadratic function relation with temperature. At 298.15 K, the standard molar formed enthalpy and free energy of the title compound molecule were respectively 2708.95 kJ·mol^-1 and 2972.13 kJ·mol^-1. (author)