Hangzhou Institute of Advanced Studies, Zhejiang Normal University, 1108 Gengwen Road, Hangzhou 311231, Zhejiang, PR China.
Department of Chemistry, College of Life Sciences, Zhejiang Sci-Tech University, Hangzhou 310018, China.
Spectrochim Acta A Mol Biomol Spectrosc. 2023 Jan 5;284:121808. doi: 10.1016/j.saa.2022.121808. Epub 2022 Aug 30.
The isotropic and anisotropic component Raman spectra and H NMR of N-methylpyrrolidone (NMP)/carbon tetrachloride and NMP/methanol binary mixture at different volume fractions have been collected. The polarization Raman frequencies and frequency differences of CO stretching vibration for NMP/methanol mixture show unique concentration-dependence and abrupt jump feature. It is found that the H-bond between solute and solvent does not destroy the noncoincidence (NCE) phenomenon, but has a significant synergistic effect on the NCE. Two distinctive clusters constrained by H-bond and intermolecular interactions were easily determined by means of linear extension method from abrupt jump curve. The experimental phenomena can be well explained by aggregation-induced splitting theory with the proposed dimer structure and H-bond cluster model. Applying the same methodology the conformation of NMP in water has been determined successfully. The establishment of this method will play an important role in the determination of biomolecule aggregation behavior and supramolecular self-assembly structure.
已收集到不同体积分数下 N-甲基吡咯烷酮（NMP）/四氯化碳和 NMP/甲醇二元混合物的各向同性和各向异性组分拉曼光谱和 H NMR。NMP/甲醇混合物 CO 伸缩振动的偏振拉曼频率和频率差表现出独特的浓度依赖性和突然跳跃特征。发现溶质和溶剂之间的氢键不会破坏非一致性（NCE）现象，而是对 NCE 具有显著的协同作用。通过线性扩展方法，从突然跳跃曲线很容易确定由氢键和分子间相互作用约束的两个不同的簇。实验现象可以很好地用提出的二聚体结构和氢键簇模型的聚集诱导分裂理论来解释。应用相同的方法成功地确定了 NMP 在水中的构象。该方法的建立将在生物分子聚集行为和超分子自组装结构的测定中发挥重要作用。
