Research and Development Centre, Bharathiar University, Coimbatore, India.
Spectrochim Acta A Mol Biomol Spectrosc. 2012 Jun 15;92:67-77. doi: 10.1016/j.saa.2012.02.036. Epub 2012 Feb 20.
The solid phase FTIR and FT-Raman spectra of methylboronic acid (MBA) have been recorded in the regions 400-4000 and 50-4000 cm(-1), respectively. The spectra were interpreted interms of fundamentals modes, combination and overtone bands. The structure of the molecule was optimized and the structural characteristics were determined by density functional theory (B3LYP) and HF method with 6-311++G(d,p) as basis set. The vibrational frequencies were calculated for most stable conformer and were compared with the experimental frequencies, which yield good agreement between observed and calculated frequencies. The infrared and Raman spectra were also predicted from the calculated intensities. (1)H and (13)C NMR spectra were recorded and (1)H and (13)C nuclear magnetic resonance chemical shifts of the molecule were calculated using the gauge independent atomic orbital (GIAO) method. UV-visible spectrum of the compound was recorded in the region 200-400 nm and the electronic properties HOMO and LUMO energies were calculated by time-dependent TD-DFT approach. Mulliken charges of the MBA molecule was also calculated and interpreted. The geometric parameters, energies, harmonic vibrational frequencies, IR intensities, Raman intensities and absorption wavelengths were compared with the available experimental data of the molecule.
甲硼烷酸（MBA）的固相 FTIR 和 FT-Raman 光谱分别在 400-4000 和 50-4000 cm(-1) 范围内记录。光谱通过基本模式、组合和泛音带进行了解释。通过密度泛函理论（B3LYP）和 HF 方法，使用 6-311++G(d,p)作为基组对分子结构进行了优化和结构特征的确定。对最稳定构象进行了振动频率的计算，并与实验频率进行了比较，得到了观察到的和计算到的频率之间的良好一致性。还从计算的强度预测了红外和拉曼光谱。记录了 (1)H 和 (13)C NMR 谱，并使用无标度原子轨道（GIAO）方法计算了分子的 (1)H 和 (13)C 核磁共振化学位移。在 200-400nm 范围内记录了化合物的紫外-可见光谱，并通过时间相关 TD-DFT 方法计算了 HOMO 和 LUMO 能量。还计算并解释了 MBA 分子的 Mulliken 电荷。比较了 MBA 分子的几何参数、能量、谐波振动频率、IR 强度、Raman 强度和吸收波长与分子的可用实验数据。
