Am1 semi-empirical calculation to study the nature of di- and tri-molecular assembly of π,π-aromatic interactions

Abstract EN

A theoretical study of semi-empirical calculations of AM1 level was used to characterize the self-assembly of carbazole, tetracyanoethylene, 2, 3-dichloro-5, 6-dicyano-p-benzoquinone, and 2, 4, 7-trinitro-9-fluorenone.

Carbazole is an electron-rich system, while tetracyanoethylene, 2, 3-dichloro-5, 6-dicyano-p-benzoquinone, and 2, 4, 7-trinitro-9 fluorenone are electron-deficient systems.

Since all of these molecules contain aromatic rings and π systems, their self-organization is mainly based on aromatic interactions and donor–acceptor interactions.

The energetic and physical properties of these molecular systems, such as heat of formation, HOMO–LUMO gap, binding energy, dipole moment, and mean polarizability were calculated.

The 3D potential energy surfaces of donor–acceptor aromatic systems involving three units recognition have also been calculated.

Plots of heat of formation of molecular systems vs interplaner distances have the same shape as Lennard–Jones 6, 12 potentials where there is energy minimum in a deep potential energy well at an equilibrium interplaner distance.

The study shows that these donor- acceptor interactions are very favorable and give a clear picture about the nature of the self-assembly of molecular complex systems.