Bpytrisalen/Bpytrisaloph: A Triangular Platform That Spatially Arranges Different Multiple Labile Coordination Sites

Abstract

Complexes that possess multiple metals in their proximity exert useful functions such as multivalent capture and catalytic activities. However, it is often challenging to arrange multiple metals with regular distances and to maintain the reactive coordination sites. We have now designed and synthesized organic macrocyclic ligands, bpytrisalen and bpytrisaloph, as platforms to spatially arrange different kinds of metals and their coordination sites. Metals coordinating to the bpy N2 units of the triangular ligands are assembled in the cavity with their labile coordination sites directed inward. Meanwhile, the metals at the salen/saloph N2O2 units have axial coordination sites that are vertically pointing out of the triangle. As a result, planar homo- and heterohexanuclear complexes with different kinds of coordination sites are obtained. Furthermore, a double-decker structure was selectively constructed upon coordinating a ditopic linker ligand to the axial coordination sites of the salen units, which shows the orthogonality of the coordination sites at the bpy and salen units. The consistency in the array of metal centers and their coordination sites irrespective of the elements is a desirable feature in the pursuit of applications for the multinuclear complexes.

Tri-Manganese(III) Salen-Based Cryptands: A Metal Cooperative Antioxidant Strategy that Overcomes Ischemic Stroke Damage In Vivo

“…Early on Akine, − Nabeshima, and others pioneered the chemistry of Salen-based cryptands with an eye toward improving guest recognition and selectivity for a range of applications, including materials and catalysis. Within the context of ongoing efforts to explore potential biological applications of metallosalen complexes, − we have recently reported biocompatible luminescent Zn and Al tris­(Salen) cryptands that are effective for live cell imaging.…”

Self-assembly of a Mixed Valence Copper Triangular Prism and Transformation to Cage Triggered by an External Stimulus

“…The rational design of coordination cages is available by utilizing the directional feature of coordination bonds and defined coordination geometry of metal ions . Many types of prismatic cages have been successfully designed and synthesized by precisely choosing metal ions and multitopic ligands (e.g., triangular prism, quadrangular prism, pentaprism, and hexagonal prism). The metal–organic triangular prism is the simplest prismatic structure, which can be obtained by combination of the end-capped metal centers as vertexes, the tritopic planar ligand as roofs and floors, and the bidentate linear ligands as pillars in a 6:2:3 molar ratio .…”

A Sandwich‐Shaped Hexanuclear Silver Complex with a Giant Cavity Constructed from a Macrocycle with Inward Chelating Units

“…Such metallomacrocycles have various uses including molecular recognition, [2–6] template‐directed synthesis, [7–9] molecular machines, [10] and catalysis [11–15] . Furthermore, the coordination linking of multiple macrocycles is a useful strategy to provide a large and well‐defined inner space that cannot be created only by its macrocyclic component [16–22] . We have recently reported hexapap, a macrocyclic hexamer of pap (2‐[(pyridin‐2‐ylmethylene)amino]phenol) [23,24] .…”

“…[11][12][13][14][15] Furthermore, the coordination linking of multiple macrocycles is a useful strategy to provide a large and well-defined inner space that cannot be created only by its macrocyclic component. [16][17][18][19][20][21][22] We have recently reported hexapap, a macrocyclic hexamer of pap (2-[(pyridin-2-ylmethylene)amino]phenol). [23,24] Six pap chelating units of the hexapap are inwardly arranged on the giant and rigid macrocyclic scaffold.…”