山东大学杨志杰团队报道了长阶胶体纳米晶体的螺旋组装及其融合成连续结构。相关研究成果于2025年1月7日发表在《美国化学会杂志》。

手性集中体现了化学的复杂性，代表了它的一些最显著的成就。然而，从非手性构建块精确合成手性结构，仍然是合成化学和材料科学中一个深刻而持久的挑战。

该文中，研究人员证明了非手性胶体纳米晶体，包括金和银纳米晶体，可以在手性分子的帮助下组装成长程有序的螺旋组件。胶体银或金纳米晶体与π共轭苝二亚胺分子之间的同步聚集动力学，使纳米晶体能够精确地遵循分子组装的螺旋路径。这导致形成延伸超过数十微米的螺旋纳米晶体组件。这些螺旋组织的纳米晶体具有高位置精度，显示出线性尺寸依赖的手性特性。

此外，除了常见的双螺旋组件外，还可以观察到更复杂的螺旋组件，其特征是三重、四重和五重纳米晶体链。最后，这些由离散的银纳米晶体组成的螺旋组件，可以在硫化反应后融合成连续的Ag₂S螺旋结构，最终通过阳离子交换过程形成各种金属硫化物螺旋。

附：英文原文

Title: Helical Assemblies of Colloidal Nanocrystals with Long-Range Order and Their Fusion into Continuous Structures

Author: Caikun Cheng, Benyou Li, Zhenyu Feng, Rongjuan Liu, Yuting Bi, Qiang Li, Jingjing Wei, Zhijie Yang

Issue&Volume: January 7, 2025

Abstract: Chirality epitomizes the sophistication of chemistry, representing some of its most remarkable achievements. Yet, the precise synthesis of chiral structures from achiral building blocks remains a profound and enduring challenge in synthetic chemistry and materials science. Here, we demonstrate that achiral colloidal nanocrystals, including Au and Ag nanocrystals, can assemble into long-range-ordered helical assemblies with the assistance of chiral molecules. The synchronized aggregation kinetics between colloidal silver or gold nanocrystals and π-conjugated perylene diimide molecules enables the nanocrystals to precisely follow the helical pathways of the molecular assemblies. This results in the formation of helical nanocrystal assemblies extending over tens of micrometers. These helically organized nanocrystals, exhibiting high positional precision, display linear size-dependent chiroptical properties. Furthermore, more intricate helical assemblies, featuring triple, quadruple, and quintuple nanocrystal strands, can be observed in addition to the commonly encountered double helical assemblies. Finally, these helical assemblies, composed of discrete Ag nanocrystals, can fuse into continuous Ag2S helical structures following a sulfidation reaction, ultimately leading to the formation of diverse metal sulfide helices through cation exchange processes.

DOI: 10.1021/jacs.4c13831

Source: https://pubs.acs.org/doi/abs/10.1021/jacs.4c13831