title: NMR and NQR parameters of the SiC-doped on the (4,4) armchair single-walled BPNT: a computational study.
abstract: The structural properties, NMR and NQR parameters in the pristine and silicon carbide (SiC) doped boron phosphide nanotubes (BPNTs) were calculated using DFT methods (BLYP, B3LYP/6-31G) in order to evaluate the influence of SiC-doped on the (4,4) armchair BPNTs. Nuclear magnetic resonance (NMR) parameters including isotropic (CS(I)) and anisotropic (CS(A)) chemical shielding parameters for the sites of various (13)C, (29)Si, (11)B, and (31)P atoms and quadrupole coupling constant (C ( Q )), and asymmetry parameter (η ( Q )) at the sites of various (11)B nuclei were calculated in pristine and SiC- doped (4,4) armchair boron phosphide nanotubes models. The calculations indicated that doping of (11)B and (31)P atoms by C and Si atoms had a more significant influence on the calculated NMR and NQR parameters than did doping of the B and P atoms by Si and C atoms. In comparison with the pristine model, the SiC- doping in Si(P)C(B) model of the (4,4) armchair BPNTs reduces the energy gaps of the nanotubes and increases their electrical conductance. The NMR results showed that the B and P atoms which are directly bonded to the C atoms in the SiC-doped BPNTs have significant changes in the NMR parameters with respect to the B and P atoms which are directly bonded to the Si atoms in the SiC-doped BPNTs. The NQR results showed that in BPNTs, the B atoms at the edges of nanotubes play dominant roles in determining the electronic behaviors of BPNTs. Also, the NMR and NQR results detect that the Fig. 1b (Si(P)C(B)) model is a more reactive material than the pristine and the Fig. 1a (Si(B)C(p)) models of the (4,4) armchair BPNTs.
authors.affiliation: Department of Chemistry, Azadshahr Branch, Islamic Azad University, Azadshahr, Golestan, Iran. baei52@yahoo.com
authors.forename: Mohammad T
authors.initials: MT
authors.lastname: Baei
authors.forename: S Zahra
authors.initials: SZ
authors.lastname: Sayyad-Alangi
authors.forename: Ali Varasteh
authors.initials: AV
authors.lastname: Moradi
authors.forename: Parviz
authors.initials: P
authors.lastname: Torabi
mesh_terms: D001896:Boron Compounds / Q000737:chemistry*; D017554:Carbon Compounds, Inorganic / Q000737:chemistry*; D009682:Magnetic Resonance Spectroscopy / Q000379:methods*; D008958:Models, Molecular; D008968:Molecular Conformation; D043942:Nanotubes / Q000737:chemistry*; D017655:Silicon Compounds / Q000737:chemistry*
chemical_list: D001896:Boron Compounds; D017554:Carbon Compounds, Inorganic; D017655:Silicon Compounds; C022088:silicon carbide