Maldonado Noelia, Beobide Garikoitz, Reyes Efraim, Martínez José Ignacio, Gómez-García Carlos J, Castillo Oscar, Amo-Ochoa Pilar
Department of Inorganic Chemistry, Autonomous University of Madrid, 28049 Madrid, Spain.
Department of Organic and Inorganic Chemistry, University of the Basque Country (UPV/EHU), 48080 Bilbao, Spain.
Nanomaterials (Basel). 2022 Feb 17;12(4):675. doi: 10.3390/nano12040675.
This work contributes to enlightening the opportunities of the anisotropic scheme of non-covalent interactions present in supramolecular materials. It provides a top-down approach based on their selective disruption that herein has been employed to process a conventional microcrystalline material to a nanofibrillar porous material. The developed bulk microcrystalline material contains uracil-1-propionic acid (UPrOH) nucleobase as a molecular recognition capable building block. Its crystal structure consists of discrete [Cu(UPrO) (4,4'-bipy) (H O)] (4,4'-bipy=4,4'-bipyridine) entities held together through a highly anisotropic scheme of non-covalent interactions in which strong hydrogen bonds involving coordinated water molecules provide 1D supramolecular chains interacting between them by weaker interactions. The sonication of this microcrystalline material and heating at 45 °C in acetic acid-methanol allows partial reversible solubilization/recrystallization processes that promote the cross-linking of particles into an interlocked platelet-like micro-particles metal-organic gel, but during CO supercritical drying, the microcrystalline particles undergo a complete morphological change towards highly anisotropic nanofibers. This unprecedented top-down microstructural conversion provides a nanofibrillar material bearing the same crystal structure but with a highly increased surface area. Its usefulness has been tested for HPLC separation purposes observing the expected nucleobase complementarity-based separation.
这项工作有助于揭示超分子材料中非共价相互作用各向异性方案的机遇。它提供了一种基于选择性破坏的自上而下的方法，在此已被用于将传统微晶材料加工成纳米纤维多孔材料。所开发的块状微晶材料包含尿嘧啶-1-丙酸（UPrOH）核碱基作为具有分子识别能力的结构单元。其晶体结构由离散的[Cu(UPrO)(4,4'-联吡啶)(H₂O)]（4,4'-联吡啶 = 4,4'-联吡啶）实体组成，这些实体通过高度各向异性的非共价相互作用方案结合在一起，其中涉及配位水分子的强氢键提供了一维超分子链，它们之间通过较弱的相互作用相互作用。这种微晶材料在乙酸 - 甲醇中超声处理并在45°C加热，会发生部分可逆的溶解/重结晶过程，促进颗粒交联成互锁的片状微颗粒金属有机凝胶，但在CO₂超临界干燥过程中，微晶颗粒会发生完全的形态变化，转变为高度各向异性的纳米纤维。这种前所未有的自上而下的微观结构转变提供了一种具有相同晶体结构但表面积大幅增加的纳米纤维材料。其用途已针对高效液相色谱分离目的进行了测试，观察到了预期的基于核碱基互补性的分离。
