石油胶质结构性质的量子化学研究

Quantum chemical calculations have been performed on the structure of petroleum gums. The structures of the single layer (SG), double layers (DG) and triple layers (TG) for the petroleum gums were obtained. The parts of aromatic rings and alicyclic rings are approximate plane structures, while alkyl side chains extend from the plane. The distances of C—C bonds in aromatic rings, alicyclic rings and alkyl side chains of the gum are all shorter than those in benzene ring, naphthenes and alkyl group. The bonds in alkyl side chains are weaker than those in aromatic rings and alicyclic rings. This suggests that the bonds in alkyl side chains can be broken easily with proper catalysts. DG and TG are slightly different in bond distances, bond angles and net charges. Moreover, hydrogen bonds (H-bonds) are found between layers. The action energies in DG and TG are -22.8416kJ/mol and -43.8455kJ/mol, respectively. The large bulks of DG and TG may cause obstructs for their diffusion into the holes of molecular sieves.