Jalilian M R, Tayyari S F
Department of Chemistry, Faculty of Science, Al-Zahra University, Vanak, Tehran, Iran.
Spectrochim Acta A Mol Biomol Spectrosc. 2009 Sep 1;73(5):828-32. doi: 10.1016/j.saa.2009.04.020. Epub 2009 May 3.
Benzene and methanol make a minimum boiling point homogeneous binary azeotrope with the mole ratio 2:3. Some characteristic vibrational modes, as well as (1)H NMR signals change due to the azeotrope formation. The extend of interaction of these molecules causes significant changes on some vibrational modes involved, and (1)H NMR signals show some changes on their position. No IR, Raman, and NMR spectra have been reported for this constant boiling mixture, also there has not been any attempt to investigate the unit-structure of this azeotrope. In this work the FTIR, FT-Raman, and (1)H NMR spectra of pure benzene, pure methanol, and corresponding azeotrope were recorded, mutual influences resulting from azeotrope formation have been analyzed, and spectral changes has been discussed. The unit-structure of cluster has been deduced based on mole ratio, boiling point depression of constituents, and comparison among the spectra obtained by FTIR, FT-Raman, and (1)H NMR techniques.
苯和甲醇形成最低沸点均相二元共沸物，其摩尔比为2:3。由于共沸物的形成，一些特征振动模式以及¹H NMR信号会发生变化。这些分子间相互作用的程度导致所涉及的一些振动模式发生显著变化，¹H NMR信号在其位置上也显示出一些变化。尚未有关于这种恒沸混合物的红外光谱、拉曼光谱和核磁共振光谱的报道，也没有任何研究该共沸物单元结构的尝试。在这项工作中，记录了纯苯、纯甲醇以及相应共沸物的傅里叶变换红外光谱（FTIR）、傅里叶变换拉曼光谱（FT-Raman）和¹H NMR光谱，分析了共沸物形成所产生的相互影响，并讨论了光谱变化。基于摩尔比、组分的沸点降低以及通过FTIR、FT-Raman和¹H NMR技术获得的光谱之间的比较，推断出了团簇的单元结构。
