Macrocyclic assemblies

Template Strategies in the Synthesis of Functional Macrocycle Assemblies... 

The favourable intra-molecular hydrogen-bonding between the oxime proton and the phenol oxygen atom will reduce or overcome liganddigand repulsion enthalpy terms normally involved in the formation of bis-chelate complexes. The integrity of this head-to-tail macrocyclic assembly is preserved in c/.v-octahcdral complexes which are formed in the presence of a, co-diamines. [66, 67]... 

It is worth noting that the chiral metallo-macrocycles assembled with these angular bipyridine ligands were less robust than the previous ones formed from the strong Pt-alkynyl linkage. This is due to the lability of the M-pyridyl bonds. 

Montoro-Garcia C, Camacho-Garcia J, Lopez-Perez AM, et al. High-fidehty noncova-lent synthesis of hydrogen-bonded macrocyclic assemblies. Angew Chem Int Ed. 2015 54 6780-6784. 

Pyrrole-based macrocyclic assemblements were also utilized as functionalizing units for fuller-enes. Despite the fact that the first example coming to mind is a porphyrine macrocycle, the ability of such 7t-electron-rich systems to strongly bind fullerenes in a convex-planar supramolecular association will be discussed in Section 2.22.2. 

Through proper orientation of the pyridyl group relative to the zinc-porphyrin plane, macrocyclic assemblies of variant topologies are accessible. For example, favorable formation of the trimeric macrocycle 13 was achieved... 

FIGURE 19. (a) Acyclic boronate diesters form macrocyclic assemblies with coordinate amines for added stability, (b) These macrocyles bind paraquat in a 1 1 manner. 

As demonstrated by examples, these relatively novel assemblies hold promise in a number of different venues. The simple phenyl-boron-phenyl binding motif provides a unique supramolecular assembly strategy for researchers to take advantage of. Macrocyclic assemblies have been shown to serve as host molecules for molecular recognition events. Linear polymers have shown self-repair capabihties as well as serving as wide band-gap semiconductors. And porous COFs provide stable network geometries for the inclusion of guests. 

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