Molecular structure of phenyl- and phenoxyacetic acids - spectroscopic and theoretical study

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• 作者：M. Samsonowicz
• 关键词：IR ; Raman ; NMR ; DFT calculations ; Molecular electrostatic potential ; HOMO/LUMO analysis
• 刊名：Spectrochimica Acta Part A: Molecular and Biomolecular Spectroscopy
• 出版年：24 January, 2014
• 年：2014
• 卷：118
• 期：Complete
• 页码：1086-1097
• 全文大小：2174 K

文摘

The FT-IR, FT-Raman and ¹H and ¹³C NMR spectra were recorded for phenyl- and phenoxyacetic acids in comparison with benzoic acid molecule. The density functional hybrid method (B3LYP/6-311++G^**) was used to calculate optimized geometrical structures of studied compounds. The atomic charges were calculated by NBO (natural bond orbital) methods. Aromaticity indices, dipole moments and energies as well as the wavenumbers and intensities of IR spectra were calculated. The chemical shifts in NMR spectra using the gauge independent atomic orbital (GIAO) method were also analyzed. The theoretical parameters were compared to experimental characteristic of phenyl- and phenoxyacetic acids. The study of HOMO, LUMO and NBO analyses have been used to elucidate charge transfer within the molecule of title compounds. Molecular electrostatic potential (MEP) was also calculated.