Structure and properties of hexagonal carbon nanoclusters C95N of graphene-like structure

Abstract

The ideal multi-layered graphene, consisting of sp²-hybridized carbon atoms, has a sufficiently high chemical inertness with zero band gap. To change its physical and chemical properties, i.e. to increase reactivity and (or) to obtain a predetermined band gap, typically one has to transfer to carbon nanoclusters (CNC) with finite-size graphene structure; to create an ordered mono- or polyatomic vacancy system; to form so-called rippers; to produce substitution of one or more carbon atoms with electron donor or electron acceptor ones. You can combine several or all of these approaches.

It has been shown that the hexagon-shaped CNC C₉₆ allows us to convey all the properties of objects of this kind. It has just been chosen as the base in the study on the properties of nitrogen doped CNC (CNC-N).

The equilibrium spatial structure, the electronic structure and  the density distribution of single-electron energy levels of hexagon-shaped carbon nanoclusters С ₉₅N of grapheme-like structure have been calculated by means of density functional theory method (B3LYP, basis set 6-31 G**). It has been found as follows:

– the electronic ground states of odd electron isomers CNC-N C₉₅N, in some cases, depending on the position of the nitrogen atom, is not a doublet;

– the most stable C₉₅N clusters are those where the nitrogen atom occupies the pyridinic position in zigzag edges;

– equilibrium configurations of considered CNC-N C₉₅N have characteristic features inherent in those of the original cluster C₉₆;

– the value of the chemical shift of core level N1s is the lowest for the pyridinic position of nitrogen atom and increases with distance of substituting nitrogen atom from the zigzag edge that corresponds to the experimentally found regularities of its connection with the effective charge on the nitrogen atom.