Zheng Li-Qing, Servalli Marco, Schlüter A Dieter, Zenobi Renato
Department of Chemistry and Applied Biosciences , ETH Zurich , Vladimir-Prelog-Weg 3 , 8093 Zurich , Switzerland . Email:
Department of Materials , Institute of Polymer Chemistry , ETH Zurich , Vladimir-Prelog-Weg 5 , 8093 Zurich , Switzerland.
Chem Sci. 2019 Sep 24;10(42):9673-9678. doi: 10.1039/c9sc03296g. eCollection 2019 Nov 14.
A two-dimensional (2D) covalent monolayer based on [4 + 4] cycloaddition reactions between adjacent anthracene units was synthesized at an air/water interface. For structural analysis, tip-enhanced Raman spectroscopy (TERS) provides direct evidence for the covalent bonds formed between monomer molecules. For the first time, progress of the photopolymerization reaction was monitored by irradiation ( = 385 nm) of the monomer monolayer for different times, based on averaged TER spectra extracted from maps. In addition, a 2D polymerization on a Au (111) substrate was realized, which opens up new possibilities for such chemical transformations. This work uses TERS as a minimally invasive tool to investigate how the reaction conditions affect polymerization conversion. We show that the high sensitivity and the high spatial resolution of TERS can be used to estimate the crystallinity of 2D covalent monolayers, which is a key question in polymer synthesis.
一种基于相邻蒽单元之间[4 + 4]环加成反应的二维（2D）共价单层在空气/水界面合成。对于结构分析，针尖增强拉曼光谱（TERS）为单体分子之间形成的共价键提供了直接证据。首次基于从图谱中提取的平均TERS光谱，通过对单体单层进行不同时间的辐照（λ = 385 nm）来监测光聚合反应的进程。此外，在Au（111）衬底上实现了二维聚合，这为此类化学转化开辟了新的可能性。这项工作使用TERS作为一种微创工具来研究反应条件如何影响聚合转化率。我们表明，TERS的高灵敏度和高空间分辨率可用于估计二维共价单层的结晶度，这是聚合物合成中的一个关键问题。
