Department of Pharmacognosy and Phytochemistry, Medical University of Silesia in Katowice, School of Pharmacy with the Division of Laboratory Medicine in Sosnowiec, ul. Jagiellonska 4, 41-200 Sosnowiec, Poland.
Institute of Physics, University of Silesia, ul. 75 Pulku Piechoty 1A, 41-500 Chorzów, Poland.
J Chem Phys. 2018 Feb 21;148(7):074501. doi: 10.1063/1.5011672.
In this paper, 1,6-anhydro-β-D-glucopyranose (anhGLU), 1,6-anhydro-β-D-mannopyranose (anhMAN), and 1,6-anhydro-β-D-galactopyranose (anhGAL), three new materials that form the Orientationally Disordered Crystal (ODIC) phase, have been thoroughly investigated using various experimental techniques. All measurements clearly indicated that these compounds possess a series of very interesting physical properties that are considerably different than those reported for ordinary plastic crystals. X-Ray diffraction investigations have revealed enormously long-range static correlations between molecules, reaching even 120 Å. Moreover, dielectric studies showed that besides Freon 113, the investigated anhydrosaccharides are the most fragile systems that form the ODIC phase. Further analysis of Fourier transform infrared spectra indicated that such peculiar behavior of anhydrosaccharides might be closely related to multidirectional H-bonds of various strengths that most likely affect the number of available conformations, density states, and the potential barriers in the energy landscape of these compounds. This is consistent with the results from previous reports [L. C. Pardo, J. Chem. Phys. 124, 124911 (2006) and Th. Bauer et al., J Chem. Phys. 133, 144509 (2010)] showing that the higher fragility of Freon 112 as well as a mixture of 60% succinonitrile and 40% glutaronitrile (60SN-40GN) can be closely related to the enhanced conformational ability and additional disorder introduced by various substituents, which further make energy landscape more complex. Finally, by studying the properties of 2,3,4-tri-O-acetyl-1,6-anhydro-β-D-glucopyranose (ac-anhGLU) it was found that besides the shape of the molecules, H-bonds or generally strong intermolecular interactions are extremely important parameters contributing to the ability to form the plastic phase. This is in line with current observations that in most cases the ODIC phase is created in highly interacting compounds.
本文深入研究了 1,6-脱水-β-D-吡喃葡萄糖（anhGLU）、1,6-脱水-β-D-吡喃甘露糖（anhMAN）和 1,6-脱水-β-D-吡喃半乳糖（anhGAL）这三种形成取向无序晶体（ODIC）相的新材料，采用了各种实验技术。所有测量结果均表明，这些化合物具有一系列非常有趣的物理性质，与普通塑料晶体报道的性质有很大不同。X 射线衍射研究表明，这些化合物的分子之间存在着极其长程的静态相关性，甚至可以达到 120 Å。此外，介电研究表明，除了氟利昂 113 之外，所研究的脱水糖还是形成 ODIC 相的最脆弱体系。傅里叶变换红外光谱的进一步分析表明，脱水糖的这种特殊行为可能与各种强度的多向氢键密切相关，这些氢键很可能影响化合物的构象数量、密度状态以及能量景观中的势垒。这与之前的报告结果一致[L. C. Pardo，J. Chem. Phys. 124，124911（2006）和 Th. Bauer 等人，J Chem. Phys. 133，144509（2010）]，表明氟利昂 112 和 60%琥珀腈和 40%戊二腈（60SN-40GN）混合物的更高脆性与增强的构象能力和各种取代基引入的额外无序密切相关，这进一步使能量景观更加复杂。最后，通过研究 2,3,4-三-O-乙酰基-1,6-脱水-β-D-吡喃葡萄糖（ac-anhGLU）的性质，发现除了分子的形状外，氢键或一般的强分子间相互作用是形成塑料相的重要参数。这与目前的观察结果一致，即在大多数情况下，ODIC 相是在高度相互作用的化合物中形成的。
