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

Abstract

Although the coordination chemistry of N-heterocyclic carbenes (NHCs) with transition metals has been explored for half a century, only in the past ten years has the chemistry of metallosupramolecular assemblies based on poly-NHC ligands been studied more extensively. Remarkable discrete assemblies featuring poly-NHC ligands including two-dimensional metallacycles and three-dimensional metallaprisms/cages have since emerged. These assemblies are mostly obtained starting from various imidazolium or benzimidazolium salts. Driven by the increasing interest in new supramolecular architectures from carbon donor ligands, design, and construction of poly-NHC metal assemblies has become a rapidly growing area of research. The metal-carbene bond length is fixed to approximately 2.0 Å in linear NHC-M-NHC complexes. This allows the use of such complexes bearing olefin-substituted NHC ligands as templates for subsequent photochemical [2 + 2] cycloaddition reactions. The postassembly modification of such assemblies has been actively explored in recent years. In this review, we focus on the synthetic methods, characterization, structural features, and postassembly modifications of metallosupramolecular assemblies obtained from poly-NHC ligands.

Trigonal Prismatic Cu6L3 Coordination Cage: Encapsulation of Aromatic Molecules and Tuned Photoluminescence

“…[8] However, the coordination cage with prismatic structure is unusual. [9] The cyclic trinuclear complexes (CTCs) based on d 10 coinage-metal (Cu(I), Ag(I), Au(I)) attracts researchers to investigate their distinguished properties, especially their photoluminescence properties, [10] as well as metallophilicity, [11] p-acid/base chemistry, [12] and host-guest chemistry. [13] For example, Omary et.…”

Metal‐Carbene‐Templated Photochemistry in Solution: A Universal Route towards Cyclobutane Derivatives

“…Since imidazo[1,5‐ a ]pyridine‐based compounds are also potential NHC precursors,[14c] we next synthesized an olefin‐containing bisimidazo[1,5‐ a ]pyridinium salt H 2 ‐ 11 (PF 6 ) 2 and tried to extend our idea for the preparation of cyclobutane‐bridged molecular rectangle (Scheme ). The formation of H 2 ‐ 11 (PF 6 ) 2 was verified by 1 H, 13 C{ 1 H} NMR spectroscopy and ESI mass spectrometry (see SI).…”

“…We became interested in using organometallic assemblies to control the formation of cyclobutane derivatives. Over the last few years, although we have reported several examples of metallosupramolecular rectangles and cages templated [2 + 2] photocycloadditions in solution under UV irradiation conditions, only the ligands featuring imidazole or benzimidazole were demonstrated . In order to verify the universality of this strategy, here we demonstrate the preparation of 1,2,4‐triazole‐, 1,2,3‐triazole‐ and imidazo[1,5‐ a ]pyridine‐based dinuclear Ag I tetracarbene complexes, which can be used for the exclusive preparation of cyclobutane derivatives in solution.…”

A Pt(II)‐based Hexagonal Ionic Supramolecular Coordination Complex and its DNA Interactions.

“…More than 100 years ago, Werner proposed structural descriptions of transition metal complexes in 1893 . Ever since, there has been phenomenal developments in the field of coordination chemistry that deals with species in which transition metal ions form bonds with ligands (ions or neutral molecules) . In the domain of coordination chemistry, a relatively new research subset is “coordination‐driven supramolecular chemistry” – a field of research that has been developed over the last three decades by Lehn, Stang, Fujita, Cotton, Raymond, Newkome, Mirkin, Shionoya, Nitschke, Clever, and others …”