Confinement effect on p-nitroaniline electronic spectrum and electric properties.

An analysis of the behavior of the p-nitroaniline excitations in confinement is performed. Various confining environments are chosen to demonstrate the chemical pressure exerted by a homogeneous cylindrical structure (single-walled carbon (4,4) nanotube), a heterogeneous cylindrical structure (boron nitride (4,4) nanotube), and a spheroidal homogeneous structure (C(92) fullerene buckyball of the original D(2) symmetry). The highest interaction energy was found for pNA in the carbonaceous cages; however, its estimation must be performed with a careful choice of the approximation. Boron nitride tube with a relatively large band gap appears to be an interesting environment modifying the electronic spectrum of pNA.