Indri Shashanka S, Dietrich Florian M, Wagner Avital, Hartstein Michal, Nativ-Roth Einat, Pavan Mariela J, Kronik Leeor, Salvalaglio Matteo, Palmer Benjamin A
Department of Chemistry, Ben-Gurion University of the Negev, Be'er Sheba 8410501, Israel.
Department of Chemical Engineering, University College London, London WC1E 7JE, United Kingdom.
J Am Chem Soc. 2025 Jun 4;147(22):19139-19147. doi: 10.1021/jacs.5c04543. Epub 2025 May 23.
Understanding how crystals nucleate is a key goal in materials, biomineralization, and chemistry. Many inorganic materials are known to crystallize "nonclassically" by particle attachment. However, a molecular-level understanding of small molecule crystallization is hampered by the complexity and time scales of nucleation events, which are often too large to simulate and too small to observe. Here, by combining unbiased molecular dynamics simulations and experiments, we uncover this nucleation "blind spot" to elucidate the nonclassical crystallization mechanism of the nucleobase, guanine. The multi-step nucleation process begins with stacked guanine clusters, whose H-bonding and π-stacking arrangement progressively orders as they attach into nanoscopic fibers (observed by simulation and electron microscopy), partially ordered bundles, and finally, 3D periodic crystals. This work provides a foundation for understanding how organisms exquisitely control the formation of guanine and other molecular crystals, which are used ubiquitously in biology as optical and nitrogen-storage materials.
了解晶体如何成核是材料科学、生物矿化和化学领域的一个关键目标。许多无机材料已知通过颗粒附着以“非经典”方式结晶。然而，小分子结晶的分子水平理解受到成核事件的复杂性和时间尺度的阻碍，这些事件通常太大而无法模拟，又太小而无法观察。在这里，通过结合无偏分子动力学模拟和实验，我们揭示了这个成核“盲点”，以阐明核碱基鸟嘌呤的非经典结晶机制。多步成核过程始于堆叠的鸟嘌呤簇，其氢键和π-堆积排列在它们附着形成纳米纤维（通过模拟和电子显微镜观察）、部分有序束，最终形成三维周期性晶体时逐渐有序。这项工作为理解生物体如何精确控制鸟嘌呤和其他分子晶体的形成奠定了基础，这些晶体在生物学中作为光学和氮储存材料被广泛使用。
