Department of Physics (Engg.), Annamalai University, Annamalai Nagar, Chidambaram 608002, Tamil Nadu, India.
Spectrochim Acta A Mol Biomol Spectrosc. 2011 Aug;79(3):562-9. doi: 10.1016/j.saa.2011.03.034. Epub 2011 Mar 21.
The FT-IR spectrum of 2,6-di-tert-butyl-4-methylphenol [butylated hydroxy toluene] was recorded in the region 4000-400 cm(-1). The FT-Raman spectrum of butylated hydroxy toluene was also recorded in the region 3500-50 cm(-1). The molecular structure and vibrational frequencies of butylated hydroxy toluene (BHT) have been investigated with combined experimental and theoretical study. Two stable conformers of the title compound were obtained from the result of geometry optimizations of these possible conformers. The conformer 1 is (approximately 2.6 kcal/mol) more stable than conformer 2. Geometry optimizations and vibrational frequency calculations were performed by BLYP and B3LYP methods using 6-31G(d), 6-31G(d,p) and 6-31+G(d,p) as basis sets. The scaled frequencies were compared with experimental spectrum and on the basis of this comparison; assignments of fundamental vibrational modes were examined. Comparison of the experimental spectra with harmonic vibrational wavenumbers indicates that B3LYP/6-31G(d) results are more accurate. Predicted electronic absorption spectra of BHT from TD-DFT calculation have been analyzed and compared with the experimental UV-vis spectrum. The calculated HOMO and LUMO energies show that the charge transfer occurs within the molecule.
2,6-二叔丁基-4-甲基苯酚（丁基化羟基甲苯）的 FT-IR 光谱在 4000-400 cm(-1) 范围内记录。丁基化羟基甲苯的 FT-Raman 光谱也在 3500-50 cm(-1) 范围内记录。通过实验和理论研究相结合，研究了丁基化羟基甲苯（BHT）的分子结构和振动频率。从这些可能构象的几何优化结果中获得了标题化合物的两个稳定构象。构象 1 （约 2.6 kcal/mol）比构象 2 更稳定。几何优化和振动频率计算使用 BLYP 和 B3LYP 方法，使用 6-31G(d)、6-31G(d,p) 和 6-31+G(d,p) 作为基组进行。缩放频率与实验光谱进行比较，并在此基础上检查了基本振动模式的分配。实验光谱与谐波振动波数的比较表明，B3LYP/6-31G(d) 结果更准确。从 TD-DFT 计算预测的 BHT 电子吸收光谱进行了分析，并与实验 UV-vis 光谱进行了比较。计算出的 HOMO 和 LUMO 能量表明电荷转移发生在分子内。
