▎ 摘　　要

The geometry of hexafluorotribenzo[a g m]coronene with n-carbon alkyl chains [FTBC-Cn (n = 4 6 8 12)] and their supramolecule self-assembly on a highly oriented pyrolytic graphite (HOPG) surface has been optimized by molecular dynamics simulations using COMPASS force field at 0 K 298 K 333 K and 353 K Electronic properties and intermolecular interactions in graphene supramolecule assembly have been studied by the first priniciple methods based on the density functional theory (DFT) It is indicated that the thermal stability and electronic properties of graphene molecules can be tunable by attaching alkyl chains to a triangular graphene sheet and changing the length of the alkyl chain and self-assembling on a certain substrate The main results are as follows The geometry and energy gap of the FTBC-Cn single molecule and their supramolecule self-assembly on HOPG are both stable with the changes of the temperature from 0 K to 353 K and the number of carbon atoms on the alkyl chain The simulation results of geometry energy gap as well as STM images of graphene supramolecule assembly are in good agreement with the corresponding experimental results in room temperature Furthermore the electronic properties of graphene supramolecule assembly at the temperatures of 0 K 333 K and 353 K are also predicted When a triangular graphene molecule attached with six alkyl chains the energy gaps are increased and stabilized at the temperature from 0 K to 353 K. After FTBC Cn molecule self assembly on a HOPG substrate the energy gap is reduced but still stable (C) 2010 Elsevier B V All rights reserved