Xu Ting, Chen Ning, He Zhimin, Yu Pengwei, Shen Wangqiang, Akasaka Takeshi, Lu Xing
State Key Laboratory of Materials Processing and Die & Mould Technology School of Materials Science and Engineering, Huazhong University of Science and Technology, Wuhan, 430074, China.
Chemistry. 2021 Jul 16;27(40):10387-10393. doi: 10.1002/chem.202100958. Epub 2021 May 27.
Controlled crystallization of fullerene molecules into ordered molecular assemblies is important for their applications. However, the morphology engineering of fullerene[C ] assemblies is challenging, and complicated architectures have rarely been reported due to the low molecular symmetry of C molecules, which makes their crystallization difficult to control and the low production yield as well. Herein, with the assistance of solvent intercalation, a general reprecipitation approach is reported to prepare morphologically controllable C microcrystals with mesitylene as a good solvent and n-propanol as a poor solvent in one solvent system without replacing specific solvents. A series of C microcrystals with high uniformity from perfect cubes and defective hoppers to novel cruciform-pillars are obtained by intentionally tuning C concentration and the volume ratio of mesitylene to n-propanol. Among them, novel cruciform-pillar-shaped microcrystals are obtained for the first time by further decreasing the amount of mesitylene in the solvent-intercalated microcrystals. Notably, the C concentration is a key parameter for the selective growth of C hopper, rather than the volume ratio of mesitylene to n-propanol. Interestingly, the hopper-shaped microcrystals exhibit excellent photoluminescence properties relative to those of cubes and cruciform-pillars owing to the enhanced light absorption, proving their potential applications in optoelectronic devices. This study offers new insights into the morphology-controlled synthesis of other micro/nanostructured organic microcrystals and the fine tuning of photoluminescence properties of organic crystals.
将富勒烯分子可控结晶为有序分子聚集体对其应用至关重要。然而，富勒烯[C]聚集体的形态工程具有挑战性，由于C分子的低分子对称性，复杂的结构很少被报道，这使得它们的结晶难以控制且产率也低。在此，借助溶剂插层，报道了一种通用的再沉淀方法，在一个溶剂体系中以均三甲苯作为良溶剂、正丙醇作为不良溶剂，无需更换特定溶剂来制备形态可控的C微晶。通过有意调节C浓度以及均三甲苯与正丙醇的体积比，获得了一系列具有高均匀性的C微晶，从完美立方体、有缺陷的漏斗状到新型十字柱状。其中，通过进一步减少溶剂插层微晶中均三甲苯的量，首次获得了新型十字柱状微晶。值得注意的是，C浓度是C漏斗状晶体选择性生长的关键参数，而非均三甲苯与正丙醇的体积比。有趣的是，由于光吸收增强，漏斗状微晶相对于立方体和十字柱状微晶表现出优异的光致发光性能，证明了它们在光电器件中的潜在应用。这项研究为其他微/纳米结构有机微晶的形态控制合成以及有机晶体光致发光性能的精细调节提供了新的见解。
