近日，中国科学院化学研究所刘云圻院士团队研究了晶体习性可控的单晶共价有机骨架的快速合成。该研究于2025年4月28日发表在《美国化学会志》上。

由可逆性较差的共价键连接的共价有机框架（COF）缺乏动态形成和切割，因此其单晶结构的合成需要缓慢的结晶速率来减轻缺陷的形成。然而，这天然限制了传统组成和拓扑控制之外的面选择性工程的机会。为了解决这一基本限制，研究组开发了一种缩醛/CH₃COOH方案，该方案矛盾地加速了结晶过程，同时提高了结构的完美性，将60μm尺寸的单晶COF-300的合成时间缩短到1小时，同时在48小时内实现了高达120μm的晶体尺寸，在30天后实现了300μm的晶粒尺寸。 

利用这个加速合成平台，研究组通过多参数探索系统地研究了结晶景观─调节剂化学选择性、催化剂剂量、时间演变和反应温度─以解码单晶COF的可能生长机制。在此基础上，通过机器学习（ML）模型训练和预测了反应条件与单晶COF的晶体尺寸、尺寸分布、形状和生长动力学之间的关系。

附：英文原文

Title: Rapid Synthesis of Single-Crystal Covalent Organic Framework with Controllable Crystal Habits

Author: Wenqiang Gao, Ziao Chen, Jiaxin Hong, YinYue Zhang, Zhao Yang, Minghui Liu, Xinyu Wang, Shengcong Shang, Zewen You, Zhihao Shao, Jichen Dong, Yunlong Guo, Jianyi Chen, Yunqi Liu

Issue&Volume: April 28, 2025

Abstract: Covalent organic frameworks (COFs) linked by poorly reversible covalent bonds lack dynamic formation and cleavage, so the synthesis of their single-crystal structures necessitates slow crystallization rates to mitigate defect formation. This, however, inherently restricts opportunities for facet-selective engineering beyond traditional compositional and topological controls. To address this fundamental limitation, we developed an acetal/CH3COOH protocol that paradoxically accelerated crystallization while enhancing structural perfection, reducing the synthesis time for 60 μm-sized single-crystal COF-300 to 1 h, while achieving crystal sizes of up to 120 μm within 48 h, and 300 μm after 30 days. Capitalizing on this accelerated synthesis platform, we systematically interrogated crystallization landscapes through multiparameter exploration─modulator chemoselectivity, catalyst dosages, temporal evolution, and reactive temperature─to decode possible growth mechanisms of single-crystal COFs. Based on these, the relationship between reaction conditions and the crystal size, size distribution, shape, and growth dynamics of single-crystal COFs was trained and predicted by a machine learning (ML) model.

DOI: 10.1021/jacs.5c01638

Source: https://pubs.acs.org/doi/abs/10.1021/jacs.5c01638