Cation-Templated Assembly of 613 and 623 Metalla-Links

J Am Chem Soc. 2023 Mar 1;145(8):4746-4756. doi: 10.1021/jacs.2c13416. Epub 2023 Jan 30.

Abstract

Facilitated by multiple stacking interactions between components, two kinds of metalla-links containing molecular Borromean rings (623 links) and head-to-tail cyclic [3]catenanes (613 links), as isomers, were constructed in high yield by introducing tri-μ-methoxyl-dinuclear complexes [(Cp*M)2(μ-OCH3)3][OTf] (M = RhIII or IrIII, Cp* = η5-pentamethylcyclopentadienyl, OTf = triflate) as unusual cationic guests during coordination-driven assembly. The topology of these intricate structures was controlled by strategically selecting two dipyridyl ligands that differ in their coordination orientations, as evidenced by X-ray crystallography and electrospray ionization-time-of-flight/mass spectrometry analysis. The behavior of the abovementioned metalla-links in solution was monitored and further studied by the detailed NMR techniques.