Interconversion of Highly Entangled Polyhedra into Concave Polyhedra by Nitrate‐Induced Ternary Coordination

Entangled (M3 L2 )n polyhedral complexes represent a unique class of supramolecular architectures that are stabilized by relatively weak metal-acetylene interactions in cooperation with conventional metal-pyridyl coordination. Counter-anion exchange of these complexes with a nitrate (NO3- ) ion triggered formal metal insertion between the metal centers, and a heteroleptic ternary coordination mode with acetylenic, pyridyl, and nitrate donors was generated on the metal centers. As a result, the main frameworks of the polyhedral complexes M18 L12 and M12 L8 were formally extended into a new series of concave polyhedra having the compositions M21 L12 and M13 L8 , respectively. This transformation also resulted in the local disconnection of the highly entangled trifurcate topology of the framework, providing clues toward the skeletal editing of extended and complex three-dimensional (3D) architectures.