Theoretical study on the structure and properties of graphdiyne

Abstract

The graphdiyne, as a new stable carbon allotrope, is expected to be widely applied to nanosciences and devices due to unique structure and properties. In this paper we investigated the structural parameters, Wiberg bond indices, and the aromaticity of graphdiyne at the B3LYP/6-31+G* level. The calculating results indicated all the p-electrons of the carbons were able to form delocalized π-bonds and all the lengths of C-C bonds were to become average. The aromaticity of all the benzene rings was stronger than the scalene hexagon due to more negative the nucleus independent chemical shift (NICS) value. The topological properties of the compound were in good agreement with those discussed in Wiberg Bond Orders. The LUMO bandwidth (0.27 eV) of the title compound was larger than the HOMO bandwidth (0.24 eV), it indicates that the graphdiyne should be n-type material. The calculation of the odd electrons by the broken symmetry method showed that the compound contains 3.6 effectively unpaired electrons and possesses enhanced chemical reactivity. © 2013 Shanghai Institute of Organic Chemistry, Chinese Academy of Sciences.