Steric and Geometrical Frustration Generate Two Higher-Order Cu^I₁₂L₈ Assemblies from a Triaminotriptycene Subcomponent

Abstract

The use of copper(I) in metal−organic assemblies leads readily to the formation of simple grids and helicates, whereas higher-order structures require complex ligand designs. Here, we report the clean and selective syntheses of two complex and structurally distinct Cu I 12 L 8 frameworks, 1 and 2, which assemble from the same simple triaminotriptycene subcomponent and a formylpyridine around the Cu I templates. Both represent new structure types. In T-symmetric 1, the copper(I) centers describe a pair of octahedra with a common center but whose vertices are offset from each other, whereas in D 3 -symmetric 2, the metal ions form a distorted hexagonal prism. The syntheses of these architectures illustrate how more intricate Cu I -based complexes can be prepared via subcomponent self-assembly than has been possible to date through consideration of the interplay between the subcomponent geometry and solvent and electronic effects.

Triptycene-based diiron(ii) mesocates: spin-crossover in solution

“…S20, ESI†). 11,21 a The HRMS characterization pointed out a 3 : 2 ligand : metal stoichiometry for both the Fe( ii ) and Zn( ii ) containing species.…”

“…, pyridines) linked to a central Tp core, with metal centres such as Pd( ii ), 5 lanthanides 9 or Cu( i ). 11 Triple-stranded dinuclear complexes (M 2 L 3 ) are considered as the simplest examples of octahedral multinuclear assemblies. 12 When non-chiral ligands are used, racemic mixtures of the homochiral helicates (Δ,Δ and Λ,Λ) are generally obtained, 12,13 while the diastereomeric heterochiral (Λ,Δ) mesocates 14 are more uncommon.…”

“…8 Despite these wide applications, only very few examples of supramolecular assemblies containing Tp are known. These types of systems, such as coordination cages and helicates, 5,6,8–11 have typically been developed using ligands with two or three binding units ( e.g. , pyridines) linked to a central Tp core, with metal centres such as Pd( ii ), 5 lanthanides 9 or Cu( i ).…”