Department of Physics (Engg.), Annamalai University, Annamalainagar 608 002, India.
Department of Physics (Engg.), Annamalai University, Annamalainagar 608 002, India.
Spectrochim Acta A Mol Biomol Spectrosc. 2014 Mar 25;122:130-41. doi: 10.1016/j.saa.2013.10.122. Epub 2013 Nov 9.
In this study, geometrical optimization, spectroscopic analysis, electronic structure and nuclear magnetic resonance studies of 4-Methoxy-4'-Nitrobiphenyl (abbreviated as 4M4'NBPL) were investigated by utilizing HF and DFT/B3LYP with 6-31G(d,p) as basis set. The equilibrium geometry, vibrational wavenumbers and the first order hyperpolarizability of the 4M4'NBPL have been calculated with the help of density functional theory computations. The FT-IR and FT-Raman spectra were recorded in the region 4000-400 cm(-1) and 3500-50 cm(-1) respectively. Natural Bond Orbital (NBO) analysis is also used to explain the molecular stability. The UV-Vis absorption spectra of the title compound dissolved in chloroform were recorded in the range of 200-800 cm(-1). The HOMO-LUMO energy gap explains the charge interaction taking place within the molecule. Good correlation between the experimental (1)H and (13)C NMR chemical shifts in chloroform solution and calculated GIAO shielding tensors were found. The dipole moment, linear polarizability and first order hyperpolarizability values were also computed. The linear polarizability and first order hyperpolarizability of the studied molecule indicate that the compound is a good candidate of nonlinear optical materials. The chemical reactivity and thermodynamic properties of 4M4'NBPL at different temperature are calculated. In addition, molecular electrostatic potential (MEP), frontier molecular orbitals (FMO) analysis were investigated using theoretical calculations.
本研究利用 HF 和 DFT/B3LYP 方法,结合 6-31G(d,p)基组,对 4-甲氧基-4'-硝基联苯(简称 4M4'NBPL)进行了几何优化、光谱分析、电子结构和核磁共振研究。通过密度泛函理论计算,计算了 4M4'NBPL 的平衡几何形状、振动波数和一阶超极化率。在 4000-400 cm(-1) 和 3500-50 cm(-1) 范围内分别记录了 FT-IR 和 FT-Raman 光谱。还使用自然键轨道(NBO)分析来解释分子稳定性。将标题化合物溶解在氯仿中的紫外-可见吸收光谱在 200-800 cm(-1) 范围内记录。HOMO-LUMO 能隙解释了分子内发生的电荷相互作用。在氯仿溶液中实验(1)H 和(13)C NMR 化学位移与计算的 GIAO 屏蔽张量之间发现了良好的相关性。还计算了偶极矩、线性极化率和一阶超极化率值。研究分子的线性极化率和一阶超极化率表明,该化合物是一种良好的非线性光学材料候选物。在不同温度下计算了 4M4'NBPL 的化学反应性和热力学性质。此外,还通过理论计算研究了分子静电势(MEP)和前沿分子轨道(FMO)分析。