Supramolecular Boronate Assemblies

There is abundant information available on supramolecular assemblies that incorporate boronic acids. The vast majority of these ensembles have been observed primarily in the solid state, though several are stable in solution. This section begins with a brief discussion of hydrogen bonded assemblies, followed 

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Boron Sensing, Synthesis and Supramolecular Self-Assembly 17 Porous Polymers Design, Synthesis and Applications... 

Boron Sensings Synthesis and Supramolecular Self-Assembly... 

This book, entitled Boron Sensing, Synthesis and Supramolecular Self-Assembly, is part of the Monographs in Supramolecular Chemistry series edited by Philip Gale and Jonathan Steed and follows in the footsteps of BoronicAcids in Saccharide Recognition released in 2006 as part of the same series and edited by Sir J. Fraser Stoddart. This present book extends the scope in that it covers all aspects of the supramolecular chemistry of boron and also includes many interesting developments in the use of boron-based synthetic building blocks. 

In Chapter 6, B. M. Rombo et al. delve into the formation of boronate-linked supramolecular architectures based on boronate ester formation—for example, small molecule diesters form supramolecular self-assemblies in the solid state based on a phenyl-boron-phenyl sandwich motif in which these small oligomers link together to generate macrocycles and other polymers. The polymeric macrocyclics and linear structures demonstrate self-repair capabilities and constitute a new class of wide band-gap semiconducting materials. Through the incorporation of polyvalent boronates, covalent organic frameworks are described, which create highly crystalline, porous network materials. 

The rapid development of carborane chemistry is mainly due to their practical applications. For instance, the potential utility of carborane polymers as gaskets, O-rings, and electrical connector inserts has been reported. Their functionality for solvent extraction of radionuchdes as well as the potential medicinal value of the isoelectronic and isostructural boron analogues of biologically important molecules has been the subject of many review articles. For example, a number of boron compounds have been found to possess anti-inflammatory and antiarthritic activity in animal model studies. Boron compounds have also been implicated in studies designed to probe the importance of the so-called anionic subsite of acetylcholine esterase and Ach receptors. But, by far the most interesting practical apphcations of carboranes are in areas of boron neutron capture therapy (BNCT) and supramolecular assembly. 

The same research group has also exploited the sugar-boronic acid interactions as shown with 7, to create oriented supramolecular assemblies [67-75]. 

Membranes and Molecular Assemblies The Synkinetic Approach 6 Calixarenes Revisited 7 Self-assembly in Supramolecular Systems 8 Anion Receptor Chemistry 9 Boronic Acids in Saccharide Recognition 10 Calixarenes An Introduction, 2nd Edition 11 Polymeric and Self Assembled Hydrogels From Fundamental Understanding to Applications 12 Molecular Logic-based Computation 13 Supramolecular Systems in Biomedical Fields 14 Synthetic Receptors for Biomolecules Design Principles and Applications... 

In comparison to abundant examples of noncovalent supramolecular assemblies,relatively few structures have been built with strong covalent bonds. This is due to the fact that normal covalent bonds are not easily broken and reformed. One can manipulate the temperature and conditions so that the formation of stable imines, esters, disulfides, hydrazones, and boronate esters is reversible. Some examples of these covalent self-assembled systems include disulfide hosts and covalent organic frameworks. ... 

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