Structure of Asphaltene Molecules and Nanoclusters Based on Them

Abstract

The chemical, electronic, and supramolecular structures of asphaltenes, isolated from the atmospheric–vacuum distillation residue of Western Siberian crude oil, have been experimentally and theoretically studied. The chemical structure of asphaltenes has been studied by IR, UV, and visible spectroscopy. Using UV–visible absorption spectra, the electronic structure of asphaltene molecules has been determined and the highest occupied and lowest unoccupied molecular orbitals have been assessed from the effective ionization potential and effective electron affinity. The average structure of asphaltene molecules has been obtained according to chemical analysis and spectroscopy data. Quantum-chemical DFT calculations have shown that the ionization potentials and electron affinity are consistent with optical spectroscopy and electrical conductivity measurement data. The molecular mechanics calculations of nanoclusters containing up to ten molecular units of asphaltene have also shown compliance with experimental results.