Structure Elucidation of Menthol-Based Deep Eutectic Solvent using Experimental and Computational Techniques
Structure Elucidation of Menthol-Based Deep Eutectic Solvent using Experimental and Computational Techniques
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DOI：
10.1021/acs.jpca.0c10735
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发表时间：
2021-03-23
影响因子：
2.9
通讯作者：
Halim, Mohammad A.
中科院分区：
文献类型：
--
作者：
Ali, Md Ackas;Rahman, Md Sajjadur;Halim, Mohammad A.
采用实验和计算相结合的方法，详细研究了薄荷醇基深共熔溶剂（DES）的结构性质和非键相互作用。质谱分析证实了1：1 L-薄荷醇/乙酸的形成。采用分子动力学方法模拟了1：1的L-薄荷醇/乙酸体系中能量最有利的簇合物构象。采用密度泛函理论在Omega B 97 XD/6- 311 G（d，p）水平上优化了孤立结构并计算了它们的热化学性质。分析了样品的实验和计算红外光谱。此外，测量了样品的振动圆二色性（VCD）光谱，以证明手性转移。主成分分析（PCA），使数据解释更生动。所有的光谱数据分析和纳米结构解析证明DES的自发形成通过形成强氢键。实验溶剂化显色性和计算的最高占据分子轨道-最低未占据分子轨道间隙验证了推理。此外，比较VCD和IR光谱分析清楚地表明从手性薄荷醇到非手性乙酸的手性转移。这项研究表明，各种技术，如质谱，红外光谱，溶剂化显色，和计算IR-VCD可能是有用的和重要的工具来阐明DES的纳米结构和非键相互作用。VCD可以作为一个很好的补充技术，以红外光谱的手性分子为基础的DES。
The structural properties and nonbonding interactions of a menthol-based deep eutectic solvent (DES) were investigated in detail employing experimental and computational methods. A mass spectrometry analysis confirmed the formation of 1:1 L-menthol/acetic acid. A molecular dynamics simulation was used to figure out energetically most favorable cluster conformers of the 1:1 L-menthol/acetic acid system. Density functional theory at the omega B97XD/6-311G (d,p) level of theory was employed to optimize the isolated structures and to calculate their thermochemical properties. Both experimental and computed IR spectra were analyzed for the samples. Additionally, vibrational circular dichroism (VCD) spectra of the samples were measured to prove the chirality transfer. Principal component analysis (PCA) was used to make the data interpretation more vivid. All the spectral data analyses and nanostructure elucidation proved the spontaneous formation of the DES through the formation of strong hydrogen bonding. Experimental solvatochromism and computed highest occupied molecular orbital-lowest unoccupied molecular orbital gaps validated the reasoning. Moreover, comparative VCD and IR spectral analyses clearly indicated a chirality transfer from the chiral menthol to achiral acetic acid. This study suggests that various techniques, such as mass spectrometry, IR, solvatochromism, and computed IR-VCD could be useful and important tools to elucidate nanostructure and nonbonding interactions of a DES. VCD could be used as an excellent complementary technique to IR spectroscopy for a chiral molecule-based DESs.