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The tautomerism of all possible forms of tetrazole selenone (A-G), induced by proton transfer, was studied, theoretically, in different environments including gas phase, continuum solvent and microsolvated environment with one or two explicit water or ammonia molecules. The calculations were performed using two different levels of theory including mPW2PLYP and DFT-B3LYP. The 6-311++G(d,p) basis set was used for C, H, O and N and the standard relativistic effective core pseudo potential LANL2DZ basis set was used for Se atom. It was found that the tetrazole selenone, in the form of A, is the most stable isomer in all of the environments considered in this work. The kinetics of proton transfer reaction was studied in both gas and solvent environments and it was concluded that the activation energy of the reaction increases with going from the gas phase to polar solvents. Moreover, the proton transfer reaction assisted by one or two water or ammonia molecules was investigated and it was found that the activation energy significantly reduces.

Glycerol (GLY) as a by-product in bio-diesel synthesis should be converted to more valuable compounds. In the present study, MgO/graphitic carbon nitride (MgO/ g-C 3 N 4 ) was synthesized and characterized using several techniques, including FESEM, Fourier transform infrared, X-ray diffraction, TEM, and CO 2 -TPD. The MgO/g-C 3 N 4 catalysts illustrated high catalytic activity compared with pure g-C 3 N 4 and MgO for conversion of glycerol to glycerol carbonate (GC) through transesterification reaction between GLY and dimethyl carbonate (DMC). According to the results, the optimum reaction conditions were: reaction time of 4 h, reaction temperature of 80 C, molar ratio of reactants (DMC:GLY) 3:1, and MgO/C 3 N 4 catalyst dosage of 30 mg. The catalyst with a certain ratio of MgO:g-C 3 N 4 = 6:1 showed the maximum GC yield of 95.47% at 80 C and good reusability. The simple preparation method, good catalytic activity, and reusability of the catalyst shows capability of this catalytic system on an industrial scale.