Wu Xiaocui, Moro Stefania, Marks Adam, Alsufyani Maryam, Yu Zidi, Perdigão Luís M A, Chen Xingxing, Luci Alexander M T, Crockford Callum, Spencer Simon E F, Fox David J, Pei Jian, McCulloch Iain, Costantini Giovanni
Department of Chemistry, University of Warwick, Coventry, United Kingdom.
Institut Jean Lamour, CNRS, Université de Lorraine, Nancy, France.
Nat Commun. 2025 Jul 31;16(1):7031. doi: 10.1038/s41467-025-62221-y.
Aldol condensation is a crucial synthetic reaction in organic chemistry, particularly valued for fabricating conjugated polymers without the use of metals or toxic organostannanes. However, due to the lack of reliable and precise analytical methods, no direct evidence of the microstructure and sequence of synthesised polymers has been obtained, limiting control over their structure and performance. Here, by combining electrospray deposition and scanning tunnelling microscopy (ESD-STM), we analyse sub-monomer resolution images of four different n-type polymers produced via aldol condensation, revealing unexpected defects in both the sequence of (co)monomers and their coupling. These defects, observed across all polymer samples, indicate alternative side reaction pathways inherent to aldol condensation. Our findings not only uncover the reaction mechanism responsible for these defects but also bring new insights for the design of more effective synthetic pathways to minimise structural defects in conjugated polymers.
羟醛缩合是有机化学中一种关键的合成反应，在不使用金属或有毒有机锡烷的情况下制备共轭聚合物时具有特别重要的价值。然而，由于缺乏可靠且精确的分析方法，尚未获得合成聚合物微观结构和序列的直接证据，这限制了对其结构和性能的控制。在此，我们通过结合电喷雾沉积和扫描隧道显微镜（ESD-STM），分析了通过羟醛缩合制备的四种不同n型聚合物的亚单体分辨率图像，揭示了（共）单体序列及其偶联中存在的意外缺陷。在所有聚合物样品中均观察到这些缺陷，表明羟醛缩合固有的替代副反应途径。我们的发现不仅揭示了导致这些缺陷的反应机制，还为设计更有效的合成途径以最小化共轭聚合物中的结构缺陷带来了新的见解。
