Quantum Chemistry Study Of Boron And Nitrogen Substituted Graphene Alkenyl Units

Graphene has been the focus of research,but graphene again easily gathered themselves together,lead to the application of graphene is very limited.The graphene stacked or doped with other materials to form novel composites is one of the solutions.Boron nitride have very extensive application in the field of many cutting-edge.Boron nitride doped into graphene formed a new kind of material,this process may be the root of the graphene derived materials produce specificity.In order to find accurate and efficient density functional method to calculate the graphene derived materials,Boron and nitrogen atoms to replace graphene's basic unit of benzene form azaborine,with benzene,borazine for basic research.Optimized the geometrical configuration of the dimer in the MP2/aug-cc-pVTZ level,with high accuracy of the gold standard CCSD(T)/CBS binding energy as benchmark,A selection of 12 kinds of dispersion correction density functional methods,including GGA functional,hybrid functional and long-range separation hybrid functional.The binding energy of benzene dimer,1,2-dihydro-1,2-azaborine dimer,1,4,2,5-diazadiborine dimer,1,3,2,4-diazadiborine dimer and borazine dimer were calculated using the def2-TZVPP basis set.The error of the dimer binding energy was calculated on the basis of CCSD(T)/CBS,and the MD,MAD,RMSD and MAX values were calculated.All binding energies are calculated using the equalization correction method to eliminate BSSE,regardless of the deformation energy.The closer the calculation results are to the standard values,the more suitable the calculation method is for the system.It is concluded that for the energy calculation of such systems,PBE0-D3(BJ)method has the smallest RMSD value,and the dispersion of data deviation is the smallest.It is the method of calculating energy in this system,followed by TPSS-D3(BJ)method,M05-2X-D3 method can also be used as recommendation one of the ways.Benzene is one of the most typical aromatic molecule,borazine is an isoelectronic species of benzene,and it also have aromaticity.In addition,the azaborine formed by the B-N bond instead of the C-C bond also conforms to Hockel rule,a series of studies have shown that azaborine have aromaticity.The substitution of boron and nitrogen atoms has no significant effect on the geometrical structure of the molecule.In the electrostatic potential diagram,the electron density in benzene is concentrated in the ring,and the positive potential is distributed around the ring.The electron density distribution of borazine is very different from that of benzene.The negative potential is mainly concentrated on the nitrogen atom and the positive potential is around the boron atom.In the azaborines,the electron density of 1,2-dihydro-1,2-azaborine and 1,3,2,4-diazadiborine is concentrated in one region,and the electron density of 1,4,2,5-diazadiborine is zonal distribution,and the positive potential is cut off from the middle by the negative potential.