Keywords: 46–dimethyldibenzothiophene, DMDBT, thiophene sulphides, coal, density functional theory, DFT, geometric parameters, vibration frequencies, atomic charges, thermodynamics, Fukui functions, sulphur atoms, electrons, carbon atoms, electrophilic reaction, chemical reactivity, molecular orbital distributions, density, energy gaps, electronic properties
Vibrational and quantum chemical investigations of 4.6–dimethyldibenzothiophene
To study the characteristics of the thiophene sulphides in coals, the structures and properties of 4.6–DMDBT were investigated by using density functional theory (DFT) approach in the research, the following results can be illustrated, namely, the geometry parameters, vibration frequencies, total density of states and partial density of states, atomic charges, thermodynamics, Fukui functions, and frontier molecular orbital. The results of calculation have shown that the sulphur atom in the rings is easy to get electron, and the carbon atom in the rings is the centre of the electrophilic reaction. Both the S atom and C atoms have chemical reactivity, the complete description of 4.6–DMDBT orbital distributions can be illustrated from the density of state results. The vibrational frequencies of the compound's fundamental modes have been precisely assigned and analysed, the analysis and discussion of energy gaps of HOMO–LUMO and the electronic properties have been presented furthermore. [Received: September 26, 2012; Accepted: February 15, 2013].