Synthesis of Metallopolymers and Direct Visualization of the Single Polymer Chain

Zhikai Li^1,2, Yiming Li², Yiming Zhao¹, Heng Wang^2,3, Yuan Zhang^4,5, Bo Song², Xiaohong Li¹, Shuai Lu^{2, 6}, Xin-Qi Hao⁶, Saw-Wai Hla^4*, Yingfeng Tu^1*（屠迎锋）, and Xiaopeng Li^2*

¹Jiangsu Key Laboratory of Advanced Functional Polymer Design and Application, State and Local Joint Engineering Laboratory for Novel Functional Polymeric Materials, College of Chemistry, Chemical Engineering and Materials Science, Soochow University, Suzhou, Jiangsu 215123, China

²Department of Chemistry, University of South Florida, Tampa, Florida 33620, United States

³College of Chemistry and Environmental Engineering, Shenzhen University, Shenzhen, Guangdong 518055, China

⁴Nanoscience and Technology Division, Argonne National Laboratory, Lemont, Illinois 60439, United States

⁵Department of Physics, Old Dominion University, Norfolk, Virginia 23529, United States

⁶College of Chemistry, Zhengzhou University, Zhengzhou, Henan 450001, China

Z.L., Y.L., and Y.Z. contributed equally to this work

J. Am. Chem. Soc.2020,142, 6196--6205

During the past few decades, the study of the single polymer chain has attracted considerable attention with the goal of exploring the structure–property relationship of polymers. It still, however, remains challenging due to the variability and low atomic resolution of the amorphous single polymer chain. Here, we demonstrated a new strategy to visualize the single metallopolymer chain with a hexameric or trimeric supramolecule as a repeat unit, in which Ru(II) with strong coordination and Fe(II) with weak coordination were combined together in a stepwise manner. With the help of ultrahigh-vacuum, low-temperature scanning tunneling microscopy (UHV-LT-STM) and scanning tunneling spectroscopy (STS), we were able to directly visualize both Ru(II) and Fe(II), which act as staining reagents on the repeat units, thus providing detailed structural information for the single polymer chain. As such, the direct visualization of the single random polymer chain is realized to enhance the characterization of polymers at the single-molecule level.

链接：https://pubs.acs.org/doi/10.1021/jacs.0c00110