Department of Physics, Madras Christian College, East Tambaram 600059, Tamil Nadu, India.
Department of Physics, Arignar Anna Government Arts College, Cheyyar 604407, Tamil Nadu, India.
Spectrochim Acta A Mol Biomol Spectrosc. 2017 Jun 15;181:153-163. doi: 10.1016/j.saa.2017.03.045. Epub 2017 Mar 19.
Experimental and theoretical investigations on the molecular structure, electronic and vibrational characteristics of 2-Amino-3-bromo-5-nitropyridine are presented. The vibrational frequencies were obtained by DFT/B3LYP calculations employing 6-311++G (d, p) basis set. This was compared with experimental FT-IR and FT-Raman spectral data. Simulated FT-IR (4000-400cm) and FT-Raman spectra (4000-100cm) showed good agreement with the observed spectra. The molecular equilibrium geometry of the title compound was fully optimized. Quantum chemical calculations of the equilibrium geometry and the complete vibrational assignments of wavenumbers using potential energy distribution (PED) were calculated with scaled quantum mechanics. HOMO-LUMO energies, energy gap (ΔE), electronegativity (χ), chemical potential (μ), global hardness (η), softness (S) and the Fukui function were calculated for the title molecule. The title compound has a low softness value (0.239) and the calculated value of electrophilicity index (5.905) describes the biological activity. The stability and charge delocalization of the title molecule were studied by Natural Bond Orbital (NBO) analysis, Non-Linear Optical (NLO) behaviour in terms of first order hyperpolarizability, dipole moment and anisotropy of polarizability and Molecular Electrostatic Potential (MEP) were accounted. The computed values of μ, α and β for the title molecule are 1.851 Debye, 1.723×10esu and 7.428×10esu respectively. The high β value and non-zero value of μ indicate that the title compound might be a good candidate for NLO material. Thermodynamic properties of the title molecule were studied for different temperatures thereby revealing the correlations between heat capacity (C), entropy (S) and enthalpy changes (H) with temperatures. Docking studies of the title compound were scrutinized to predict the preferred binding orientation, affinity and activity of the given compound. The title compound was docked into the active site of the protein 5FCT which belongs to the class of proteins exhibiting the property as a Dihydrofolate synthase inhibitor. A minimum binding energy of -5.9kcal/mol and intermolecular energy of -6.5kcal/mol is seen in the interaction.
呈现了对 2-氨基-3-溴-5-硝基吡啶的分子结构、电子和振动特性的实验和理论研究。通过使用 6-311++G(d,p)基组的 DFT/B3LYP 计算获得了振动频率。这与实验 FT-IR 和 FT-Raman 光谱数据进行了比较。模拟的 FT-IR(4000-400cm)和 FT-Raman 光谱(4000-100cm)与观察到的光谱吻合良好。标题化合物的分子平衡几何形状得到了完全优化。使用势能分布(PED)对平衡几何形状和波数的完整振动分配进行了量子化学计算。用比例量子力学计算了 HOMO-LUMO 能、能隙(ΔE)、电负性(χ)、化学势(μ)、整体硬度(η)、柔软度(S)和福井函数。计算了标题分子的这些值。标题化合物具有低柔软度值(0.239),计算的亲电性指数(5.905)描述了生物活性。通过自然键轨道(NBO)分析研究了标题分子的稳定性和电荷离域性,根据一阶超极化率、偶极矩和极化率各向异性以及分子静电势(MEP)计算了非线性光学(NLO)行为。标题分子的μ、α和β值分别为 1.851 德拜、1.723×10esu 和 7.428×10esu。标题化合物的β值较高且μ值不为零,表明该化合物可能是一种良好的 NLO 材料候选物。研究了标题分子在不同温度下的热力学性质,从而揭示了热容量(C)、熵(S)和焓变(H)与温度之间的相关性。对标题化合物的对接研究进行了仔细检查,以预测给定化合物的优先结合取向、亲和力和活性。该化合物被对接进属于二氢叶酸合酶抑制剂类蛋白质的 5FCT 蛋白质的活性部位。在相互作用中观察到最低结合能为-5.9kcal/mol 和分子间能量为-6.5kcal/mol。