Safari Fatemeh, Katrusiak Andrzej
Faculty of Chemistry, Department of Materials Chemistry, Adam Mickiewicz University, Uniwersytetu Poznańskiego 8, 61-614 Poznań, Poland.
J Phys Chem C Nanomater Interfaces. 2021 Oct 28;125(42):23501-23509. doi: 10.1021/acs.jpcc.1c07297. Epub 2021 Oct 19.
High-pressure polymorphs can be obtained and stabilized at ambient pressure by utilizing dopants with more voluminous molecules, inducing internal strain in the structures. This effect has been confirmed for doped resorcinol and imidazole derivatives by nucleating and stabilizing their high-pressure phases under ambient conditions. The dopant molecular volume and concentration, as well as the bulk modulus of the polymorph in the binary system, are related to the stability region in the single-component phase diagram. High-pressure isothermal and isochoric recrystallizations yielded pure single crystals of resorcinol ε above 0.20 GPa and a new polymorph ζ above 0.70 GPa. These recrystallizations of pure resorcinol revealed within 1 GPa of the - phase diagram the boundaries and the stability regions of four resorcinol polymorphs α, β, ε, and ζ, contrary to the compression experiments on ambient-pressure polymorphs α and β, when the high-pressure phases were hidden behind the wide hysteresis extending to nearly 5 GPa. The hysteresis, originating from the H-bonding networks, hinders the formation of polymorphs ε and ζ when polymorphs α and β are compressed without melting or dissolving the crystals. Polymorph ζ is the only known resorcinol structure built of hydrogen-bonded layers.
通过使用分子体积更大的掺杂剂在结构中引入内应力，可以在常压下获得并稳定高压多晶型物。对于掺杂的间苯二酚和咪唑衍生物，通过在环境条件下使其高压相成核并稳定化，这一效应已得到证实。二元体系中掺杂剂的分子体积和浓度，以及多晶型物的体积模量，与单组分相图中的稳定区域有关。高压等温及等容重结晶在0.20 GPa以上得到了间苯二酚ε的纯单晶，在0.70 GPa以上得到了一种新的多晶型物ζ。纯间苯二酚的这些重结晶在1 GPa范围内的相图中揭示了四种间苯二酚多晶型物α、β、ε和ζ的边界及稳定区域，这与常压多晶型物α和β的压缩实验不同，在后者中，高压相隐藏在延伸至近5 GPa的宽滞后现象之后。这种滞后现象源于氢键网络，当多晶型物α和β在不熔化或溶解晶体的情况下被压缩时，会阻碍多晶型物ε和ζ的形成。多晶型物ζ是唯一已知的由氢键层构成的间苯二酚结构。
