Department of Physics, Afyon Kocatepe University, 03040 Afyonkarahisar, Turkey.
Spectrochim Acta A Mol Biomol Spectrosc. 2012 Oct;96:644-56. doi: 10.1016/j.saa.2012.06.042. Epub 2012 Jul 16.
This study presents the structural and spectroscopic characterization of 3,5-dibromoanthranilic acid with help of experimental techniques (FT-IR, FT-Raman, UV, NMR) and quantum chemical calculations. The vibrational spectra of title compound were recorded in solid state with FT-IR and FT-Raman in the range of 4000-400 and 4000-50 cm(-1), respectively. The vibrational frequencies were also computed using B3LYP method of DFT with 6-311++G(d,p) basis set. The fundamental assignments were done on the basis of the total energy distribution (TED) of the vibrational modes, calculated with scaled quantum mechanical (SQM) method. The (1)H, (13)C and DEPT NMR spectra were recorded in DMSO solution and calculated by gauge-invariant atomic orbitals (GIAO) method. The UV absorption spectra of the compound were recorded in the range of 200-400 nm in ethanol, water and DMSO solutions. Solvent effects were calculated using time-dependent density functional theory and CIS method. The ground state geometrical structure of compound was predicted by B3LYP method and compared with the crystallographic structure of similar compounds. All calculations were made for monomeric and dimeric structure of compound. Moreover, molecular electrostatic potential (MEP) and thermodynamic properties were performed. Mulliken atomic charges of neutral and anionic form of the molecule were computed and compared with anthranilic acid.
本研究采用实验技术（FT-IR、FT-Raman、UV、NMR）和量子化学计算对 3,5-二溴邻氨基苯甲酸进行了结构和光谱表征。标题化合物的振动光谱在固态下使用 FT-IR 和 FT-Raman 在 4000-400 和 4000-50 cm(-1)范围内记录。振动频率也使用 DFT 的 B3LYP 方法和 6-311++G(d,p)基组进行了计算。根据振动模式的总能量分布（TED），通过比例量子力学（SQM）方法进行了基本分配。在 DMSO 溶液中记录了 (1)H、(13)C 和 DEPT NMR 光谱，并通过规范不变原子轨道（GIAO）方法进行了计算。在乙醇、水和 DMSO 溶液中记录了化合物的紫外吸收光谱，范围为 200-400 nm。使用时间相关密度泛函理论和 CIS 方法计算了溶剂效应。通过 B3LYP 方法预测了化合物的基态几何结构，并与类似化合物的晶体结构进行了比较。所有计算均针对化合物的单体和二聚体结构进行。此外，还进行了分子静电势（MEP）和热力学性质的计算。计算了中性和阴离子形式的分子的 Mulliken 原子电荷，并与邻氨基苯甲酸进行了比较。
