Synthesis and crystal structures of twisted three-dimensional assemblies of adamantane-bridged tris-NHC ligands and Ag^I

Abstract

Two adamantane-bridged tripodal trisimidazolium or trisbenzimidazolium salts were designed as C 3vsymmetrical tricarbene ligands and synthesized in good yields. The reaction of the tripodal trisazolium salt precursors with silver oxide provided trisilver hexacarbene complexes bearing a three-dimensional framework. Multinuclear NMR spectroscopy and mass spectrometry data showed that the complexes were symmetric structures of two tricarbene ligands, three metal ions, and three counter anions. X-ray crystallographic analyses revealed that both complex cations adopted a highly twisted conformation. The complex cations built from the trisimidazolium salts were arranged into columnar structures through CH/π interactions, which were assembled into a three-dimensional network structure by intermolecular CH/F interactions via hexafluorophosphate anions. The complex cations generated from the trisbenzimidazolium salts were aligned into columnar structures, which were arranged into a network structure through CH/π interactions. Solvents and counter anions were accommodated in the spaces of the crystalline lattices.

Preparation and Post-Assembly Modification of Metallosupramolecular Assemblies from Poly(N-Heterocyclic Carbene) Ligands

“…Both proligands react with Ag 2 O to give the three-dimensional cage-like complexes 311 and 312 (Scheme ). , The molecular structure of 311 was initially determined in solution by NMR spectroscopy and high-resolution cold-spray ionization mass spectrometry (CSI-MS). An X-ray diffraction study showed subsequently that the trisilver hexacarbene complex cation features only a small internal cavity with nonbonding distances between the silver atoms ranging from 12.53 to 13.36 Å.…”

“…Complexes 313 and 314 were synthesized as described for 311 and 312 (Scheme ). , The introduction of the larger benzimidazolin-2-ylidenes does not alter the structural parameters significantly, and the molecular structures of 311 and 313 are thus very similar. Again, the complex with the long N -alkyl wingtips 314 aggregated into a vesicular structure with a diameter of ca.…”