Rijal Ramesh, Sah Manoj, Lamichhane Hari Prasad
Department, St. Xavier's College, Kathmandu, Nepal.
Central Department of Physics, Tribhuvan University, Kirtipur, Kathmandu, Nepal.
Heliyon. 2023 Mar 21;9(3):e14801. doi: 10.1016/j.heliyon.2023.e14801. eCollection 2023 Mar.
The ground state molecular energy, vibrational frequencies and HOMO-LUMO analysis of the title compound have been calculated with density functional theory in the B3LYP/6-311 + G (d,p) basis set using Gaussian 09 W software. The FT-IR spectrum of pseudoephedrine has been computed in the gas phase and in the presence of solvent water both in neutral and anionic structures. The TED assignments of the vibrational spectra have been assigned in the selected intense region. On isotopic substitution of carbon atoms, the shifting of frequencies is distinctly observed. The reported values and HOMO-LUMO mappings reveal the possibility of different charge transfers occurring within the molecule. A MEP map is depicted and the Mulliken atomic charge is also calculated. The UV-Vis spectra have been illustrated and explained from the frontier molecular orbitals using a TD-DFT approach.
使用高斯09 W软件，在B3LYP/6-311 + G(d,p)基组下，通过密度泛函理论计算了标题化合物的基态分子能量、振动频率以及HOMO-LUMO分析。在气相以及存在溶剂水的中性和阴离子结构中计算了伪麻黄碱的傅里叶变换红外光谱。在选定的强吸收区域对振动光谱进行了振动模式归属。在碳原子进行同位素取代时，明显观察到频率的移动。所报道的值和HOMO-LUMO映射揭示了分子内发生不同电荷转移的可能性。绘制了分子静电势图并计算了Mulliken原子电荷。使用含时密度泛函理论方法，从前沿分子轨道对紫外可见光谱进行了说明和解释。
