شانزدهمین کنگره شیمی ایران th The 16 Iranian Chemistry Congress دانشگاه یزد 81-81 شهریور 8129 Theoretical Investigation of a New Nanostructure Fullerene; C40N20 with a Nitrogen Belt A-R. Nekoei*, S. Haghgoo Department of Chemistry, Shiraz University of Technology, Shiraz 71557-313, Iran Since the discovery of C60 fullerene by Kroto et al. [1], a considerable amount of work has been carried out in the field of the structural, electronic and optical properties of carbon fullerenes [2].The cage structure of fullerene entails three types of doping, namely endohedral, exohedral and substitutional doping by heteroatoms like boron or nitrogen [3, 4].Nitrogen-doped carbon nonomaterials are of special importance since they exhibit variable electronic properties, and they may be the building materials for future nanometer electronics. This is because their band gaps and electronic polarizations could vary with different substitute doping [2]. In 2012, a theoretical investigation has been performed on a series of even numbered nitrogen-doped fullerenes (C60-2nN2n for n=1 to n=12, including C40N20) with separate nitrogen atoms using Density Functional Theory (DFT) method as implemented in the GAMESS software with6-31G basis sets [5]. In the present study, the full optimized geometries and also the harmonic vibrational frequencies of two isomers of C40N20, one with a nitrogen belt and the second with separated nitrogens, have been investigated. All computations have been carried out using Gaussian 03W and NBO 5.0 programs, employingthe ab initio self-consistent Hartree-Fock (HF) method at 3-21G and 6- 31G(d) basis sets, and also the B3LYP functional of the DFT method at 6-31G(d) basis set. Also the structures of both C60 and N60 nanomaterials have been fully optimized and the obtained results have been used for comparison with those of C40N20. Besides the molecular structures, several properties of the mentioned compounds such as the vibrational frequencies, atomic NBO charges, second order perturbation theory analyses of donor-acceptor charge transfer in NBO basis, HOMO-LUMO surface energies and their band gaps, the atomization energies, the ionization potentials and their electron affinities have been calculated and investigated. The results show that C40N20 fullerene type nanostructure, with a belt of nitrogen atoms, is also stable like its nitrogen separated isomers, however with less stability. Moreover, some interesting different properties compared to its isomerwith separated nitrogens have been indicated. Archive of SID References [1] H.W. Kroto, J.R. Heath, S.C. O'Brien, R.F. Curl, R.E. Smalley, Nature 318 (1985) 162. [2]M.S. Dresselhaus, G. Dresselhaus, P.C. Eklund, Science of Fullerenes and Carbon Nanotubes, Academic, NewYork,1996. [3]R.H. Xie, G.W. Bryant, J. Zhao, V.H. Smith, Jr., A. Di Carlo, A. Pecchia, Phys. Rev. Lett. 90 (2003) 206602. [4] R.H. Xie, G.W. Bryant, G. Sun, T. Kar, Z. Chen, V.H. Smith, Jr., Y. Araki, N. Tagmatarchis, H. Shinohara, O. Ito, Phys. Rev. B 69 (2004) 201403(R). [5]K. Srinivasu, N.K. Jena, S.K. Ghosh, AIP Advances 2 (2012) 042111. P758T7 1434 www.SID.ir.