Multifunctional Tricarbazolo Triazolophane Macrocycles: One‐Pot Preparation, Anion Binding, and Hierarchical Self‐Organization of Multilayers
Chemistry–A European Journal, 2016•Wiley Online Library
Programming the synthesis and self‐assembly of molecules is a compelling strategy for the
bottom‐up fabrication of ordered materials. To this end, shape‐persistent macrocycles were
designed with alternating carbazoles and triazoles to program a one‐pot synthesis and to
bind large anions. The macrocycles bind anions that were once considered too weak to be
coordinated, such as PF6−, with surprisingly high affinities (β2= 1011 m− 2 in 80: 20
chloroform/methanol) and positive cooperativity, α=(4 K2/K1)= 1200. We also discovered …
bottom‐up fabrication of ordered materials. To this end, shape‐persistent macrocycles were
designed with alternating carbazoles and triazoles to program a one‐pot synthesis and to
bind large anions. The macrocycles bind anions that were once considered too weak to be
coordinated, such as PF6−, with surprisingly high affinities (β2= 1011 m− 2 in 80: 20
chloroform/methanol) and positive cooperativity, α=(4 K2/K1)= 1200. We also discovered …
Abstract
Programming the synthesis and self‐assembly of molecules is a compelling strategy for the bottom‐up fabrication of ordered materials. To this end, shape‐persistent macrocycles were designed with alternating carbazoles and triazoles to program a one‐pot synthesis and to bind large anions. The macrocycles bind anions that were once considered too weak to be coordinated, such as PF6−, with surprisingly high affinities (β2=1011 M−2 in 80:20 chloroform/methanol) and positive cooperativity, α=(4 K2/K1)=1200. We also discovered that the macrocycles assemble into ultrathin films of hierarchically ordered tubes on graphite surfaces. The remarkable surface‐templated self‐assembly properties, as was observed by using scanning tunneling microscopy, are attributed to the complementary pairing of alternating triazoles and carbazoles inscribed into both the co‐facial and edge‐sharing seams that exist between shape‐persistent macrocycles. The multilayer assembly is also consistent with the high degree of molecular self‐association observed in solution, with self‐association constants of K=300 000 M−1 (chloroform/methanol 80:20). Scanning tunneling microscopy data also showed that surface assemblies readily sequester iodide anions from solution, modulating their assembly. This multifunctional macrocycle provides a foundation for materials composed of hierarchically organized and nanotubular self‐assemblies.
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