Precise Synthesis of Concentric Ring, Helicoid, and Ladder Metallo-Polymers with Chevron-Shaped Monomers

Abstract

Molecular geometry represents one of the most important structural features and governs physical properties and functions of materials. Nature creates a wide array of substances with distinct geometries but similar chemical composition with superior efficiency and precision. However, it remains a formidable challenge to construct abiological macromolecules with various geometries based on identical repeating units, owing to the lack of corresponding synthetic approaches for precisely manipulating the connectivity between monomers and feasible techniques for characterizing macromolecules at the single-molecule level. Herein, we design and synthesize a series of tetratopic monomers with chevron stripe shape which serve as the key precursors to produce four distinct types of metallo-macromolecules with well-defined geometries, viz., the concentric hexagon, helicoid polymer, ladder polymer, and cross-linked polymer, via platinum–acetylide couplings. Concentric hexagon, helicoid, and ladder metallo-polymers are directly visualized by transmission electron microscopy, atomic force microscopy, and ultra-high-vacuum low-temperature scanning tunneling microscopy at the single-molecule level. Finally, single-walled carbon nanotubes (SWCNTs) are selected as the guest to investigate the structure–property relationship based on such macromolecules, among which the helicoid metallo-polymer shows high efficiency in wrapping SWCNTs with geometry-dependent selectivity.

Near-infrared metal agents assisting precision medicine: from strategic design to bioimaging and therapeutic applications

“…Although many terpyridinebased MOCs composed of other types of metal ions (e.g., Zn, Fe, Cd, and Co) have recently been reported, most of the terpyridine-based MOCs are located in visible light region, which limits their further biomedical applications. [331][332][333] Therefore, it is critical to enrich the molecular library of NIR MOCs and further screen MOCs with excellent performance. In particular, the successful development of NIR-IIa/IIb absorption/emission (NIR-IIa, 1300-1400 nm; NIR-IIb, 1500-1700 nm) MOCs would represent a qualitative leap in precision diagnosis and treatment.…”

Steering the Surface-Confined Self-Assembly of Multifunctional Star-Shaped Molecules

“…To conclude, all the shape-persistent molecular aggregates ( f , h , r , t , and tt ) contain symmetric cavities with different sizes and are built of an even number of chevron-like linkers H . Furthermore, to our satisfaction, the flower-like hexamers f and noodle-like molecular chains share many morphological similarities with the metallo-macromolecules synthetized recently on the Ag(111) surface by Su and colleagues . The good matching of the simulated and experimentally prepared nanostructures is not accidental, as these metallo-constructs comprise the four-armed chevron-shaped monomers glued by Pt–acetylide bonds with a linear geometry, exactly as it is in the case of isolated aggregates comprising C 1 -symmetrical tectons H .…”

A library of vinyl phosphonate anions dimerize with cyanostars, form supramolecular polymers and undergo statistical sorting

“…19,20 The discovery of reliable linkage chemistries led to the use of dimers in various applications [21][22][23][24][25][26][27][28][29][30][31][32][33] and to construct sophisticated assemblies. 14,20,[34][35][36][37][38][39][40] The versatility of these dimers can be amplied when they are covalently modied to create a variety of molecular building blocks. 3,5,20,41 For example, 35 a variety of architectures were assembled from a series of guest molecules prepared using the same synthetic route.…”