Strength and stability of π-π interaction between substituted benzene ring structures and graphene: Theoretical and molecular dynamics study

Abstract

Adsorption between graphene and organic drug molecules attracts enormous attention for its wide application in drug delivery. π-π interaction, as one of the most important adsorption mechanisms, occurs between substituted benzene ring structure in organic drug molecule and graphene. This mechanism effectively prevents the degradation of molecular structure of drug, ensures its functional activity and promotes controlled release of drugs. It is worth noting that the type and quantity of substituents on the benzene ring have a significant impact on the strength and stability of π-π interactions. In this study, we cover features of eight kinds of substituents, and explore strength and stability of π-π interaction between graphene and substituted benzene ring structures from a mechanical perspective. The results demonstrate the advantages of substituents in enhancing adsorption strength. Electron-withdrawing substituents show more stronger enhancement effect than electron-donating substituents. Further research reveals that electrostatic interaction is the main enhancement mechanism for electron-withdrawing substituents. In addition, molecular dynamics simulations provide a comparison of adsorption stability among different substituents. Theoretical and simulation studies provide valuable mechanistic understanding of substituents in enhancing adsorption performance, contributing to the design and optimization of more targeting graphene carriers for drug molecules.