As we all know asphaltene is defined as " The highest molecular weight component in the crude oil that is insoluble in light n-alkanes such as n-pentane or n-heptane and soluble in aromatics such as toluene or xylene "
But how aromatics are dissolving asphaltene in oil and playing a significant role in stabilizing it while aromatics are normally non-polar, but the the asphaltene is polar, is it by pi-pi aromatic interactions, or because of heteroatoms that can exist in aromatics which gives a certain polarity to the aromatics so they can dissolve asphaltene, or for some other reason?