不同温度下PYX在3种溶剂中的结晶形貌预测

Crystal Morphology Prediction of PYX in Three Solvents at Different Temperatures

本文应用分子动力学模拟方法,模拟了2,6-二苦氨基-3,5-二硝基吡啶(PYX)在真空中的晶体形貌。通过计算溶剂和晶面之间的相互作用能,修正了附着能,模拟出5种温度条件下PYX在3种溶剂(二甲基亚砜(DMSO)、N,N-二甲基甲酰胺(DMF)、N-甲基吡咯烷酮(NMP))中的晶体形貌。结果表明:PYX在真空条件下主要显露的3个晶面分别是(0 1 1)晶面、(1 0 1)晶面、(1 1 0)晶面,总面积占比为95.975%,PYX在真空中的晶体形貌是较为规整的多面体,纵横比为1.388。PYX各晶面与3种不同溶剂的相互作用能差异较大,导致各晶面修正附着能的差异较大,而且不同温度对晶面能量的影响也较显著,导致形貌各不相同。其中,298 K时NMP溶剂的作用和418 K时DMF溶剂的作用,均促使PYX呈现出类球体,纵横比分别是1.311和1.322,为制备PYX球晶提供方向。

Molecular dynamics simulation was applied to simulate the crystal morphology of 2,6-hexanitrodiphenyl-amine-3,5-dinitropyridine(PYX)in vacuum,and the attachment energy was modified by calculating the interaction energy between solvent and crystalline surface.The crystal morphologies of PYX in three solvents of dimethyl sulfoxide(DMSO),N,N-dimethylformamide(DMF)and N-methylpyrrolidone(NMP)under five temperature conditions were simulated.The results show that the three main crystalline surfaces of PYX exposed under vacuum are(011),(101),and(110),with a total area ratio of 95.975%.The crystal morphology of PYX in vacuum is a relatively regular polyhedron with an aspect ratio of 1.388.The interaction energy of each crystalline surface of PYX with the three dif‐ferent solvents varies greatly.The modified attachment energy of each crystalline surface is different.The effect of different temperatures on the crystalline surface energy is also significant.Therefore,the final morphology is different.The morphology of PYX under the action of NMP solvent at 298 K shows a sphere-like shape,and the same under the action of DMF solvent at 418 K.The aspect ratios are 1.311 and 1.322,respectively.It provides help for the preparation of PYX spherical crystals.