Endohedral and exohedral complexes of 1-benzene with carbon nanotubes and high-density assembly of multiple benzenes inside of a carbon nanotube

The 1-benzene was put on the inside and surface of various armchair (n, n) (n = 6-12, 14) and zigzag (n, 0) (n = 10-17, 20) nanotubes of different diameters. The binding structure, binding energy, and effects on binding energy were analyzed. All interaction structures and the properties of the assembled complexes were investigated via density functional tight-binding method. Furthermore, we put multiple benzene molecules (2-18 benzenes) inside the armchair (10, 10), (9, 9), and (8, 8) carbon nanotubes (CNTs) and found that two types of structures were formed for the endohedral complexes of multiple benzenes-spiral symmetrical polygon and criss-crossed types, respectively. The detail of the binding energies and structure properties for (10, 10)/kBen (k = 1-6, 18), (9, 9)/kBen (k = 4, 5, 15), and (8, 8)/kBen (k = 1-8) were discussed. Furthermore, the HOMOs and LUMOs of the representative complexes were also studied to illustrate the interactions. This article offers a new assembly method to prepare a high density of benzenes inside of CNTs and offers a method for benzene adsorption by CNT.