263012-84-6Relevant academic research and scientific papers
Orthogonal Selection and Fixing of Coordination Self-Assembly Pathways for Robust Metallo-organic Ensemble Construction
Burke, Michael J.,Nichol, Gary S.,Lusby, Paul J.
, p. 9308 - 9315 (2016)
Supramolecular construction strategies have overwhelmingly relied on the principles of thermodynamic control. While this approach has yielded an incredibly diverse and striking collection of ensembles, there are downsides, most obviously the necessity to
The kinetics and mechanism of interconversion within a system of [Fe2L 3]4+helicates and [Fe4L 6]8+cages
Al-Fayaad, Hydar A.,Arachchige, Kasun S. A.,Brock, Aidan J.,Clegg, Jack K.,Luis, Ena T.,McMurtrie, John C.,Micallef, Aaron S.,Siddique, Rashid G.,Thoburn, John D.
supporting information, p. 4918 - 4921 (2021/05/26)
Nature builds simple molecules into highly complex assemblies, which are involved in all fundamental processes of life. Some of the most intriguing biological assemblies are those that can be precisely reconfigured to achieve different functions using the same building blocks. Understanding the reconfiguration of synthetic self-assembled systems will allow us to better understand the complexity of proteins and design useful artificial chemical systems. Here we have prepared a relatively simple system in which two distinct self-assembled structures, a [Fe2L3]4+ helicate and a [Fe4L6]8+ cage that are formed from the same precursors, coexist at equilibrium. We have measured the rates of interconversion of these two species and propose a mechanism for the transformation.
A Synthesis of Conjugatively Bridged Bis- and Tris-5-(2,2′-Bipyridines): Multitopic Metal Ion-Binding Modules for Supramolecular Nanoengineering
Baxter
, p. 1257 - 1272 (2007/10/03)
An efficient preparation of linear and curved bis- and branched tris-5-(2,2′-bipyridines) of nanoscopic dimensions possessing rigid conjugated bridges is presented. The synthesis, which avoids the need of protection/deprotection methodology, utilizes central bridge precursors which are outwardly diand trifunctionalized with a 5-(2-chloropyridine) synthon via a chemoselective palladium-catalyzed Sonogashira or Negishi cross-coupling protocol to yield the bridged linear (5a-c, 5f,g) and curved (6, 7) bis- and branched (8) tris-5-(2-chloropyridines). Under more forcing conditions, the ethynebridged 5-(2-chloropyridines) undergo the Stille cross-coupling reacton with 2-trimethylstannylpyridines to afford the conjugatively bridged linear (1a,b, 1g-j) and curved (2a,b, 3a,b) bis- and branched, (4a,b) tris-5-(2,2′-bipyridines) in good overall yields. The phenyl- and biphenyl-bridged linear bis-5-(2,2′-bipyridines) (1c-f) were best prepared from the bis-5-(2-bromopyridines) (5d,e) to ensure completion of the Stille cross-coupling reactions. The Stille cross-couplings showed a marked substituent effect in which the terminally phenylated bis- and tris-5-(2,2′-bipyridines) were formed in higher yields than the methyl-substituted analogues with the same bridge. The advantages of the methodology lie in its synthetic convenience and adaptibility for creating multitopic metal ion-binding scaffolds with a potentially very large variety of bridging units and substituents on the terminal pyridine rings. The bridged 5-(2-chloropyridines) may also serve as precursors for the fabrication of metal ion-coordinated conjugated polymers.
