Department of Chemistry, Azadshahr Branch, Islamic Azad University, Azadshahr, Golestan, Iran.
J Mol Model. 2012 Mar;18(3):881-9. doi: 10.1007/s00894-011-1130-4. Epub 2011 May 28.
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.
使用 DFT 方法（BLYP、B3LYP/6-31G）计算了原始和碳化硅（SiC）掺杂的硼磷纳米管（BPNTs）的结构性质、NMR 和 NQR 参数，以评估 SiC 掺杂对（4,4）扶手椅 BPNTs 的影响。核磁共振（NMR）参数包括各（13）C、（29）Si、（11）B 和（31）P 原子位置的各向同性（CS（I））和各向异性（CS（A））化学屏蔽参数，以及各（11）B 核位置的四极耦合常数（C（Q））和不对称参数（η（Q））在原始和 SiC 掺杂（4,4）扶手椅硼磷纳米管模型中进行了计算。计算表明，C 和 Si 原子掺杂（11）B 和（31）P 原子对计算 NMR 和 NQR 参数的影响比对 Si 和 C 原子掺杂 B 和 P 原子的影响更大。与原始模型相比，（4,4）扶手椅 BPNTs 的 Si（PC）（BC）模型中的 SiC 掺杂降低了纳米管的能隙并增加了它们的电导率。NMR 结果表明，与 SiC 掺杂的 BPNTs 中直接与 C 原子键合的 B 和 P 原子相比，直接与 Si 原子键合的 B 和 P 原子的 NMR 参数有明显变化。NQR 结果表明，在 BPNTs 中，边缘的 B 原子在确定 BPNTs 的电子行为方面起着主导作用。此外，NMR 和 NQR 结果表明，与原始和图 1a（Si（BC）（p））模型相比，图 1b（Si（PC）（BC））模型是一种更具反应性的材料。
