Monday, February 20, 2012

Design, synthesis and characterization of self-assembled As2L3 y Sb2L3 cryptands

Fabrication of complex structures from simple components has been a research topic of great interest in recent years. Supramolecular self-assembly processes and dynamic covalent chemistry offer a powerful set of tools for the bottom-up synthesis of complex structures with new properties and emergent functionality. A defining feature of these synthetic strategies is that information contained within relatively simple components determines the formation of much more complex structures.

Chemists have compiled an enormous library of self-assembled supramolecular complexes utilizing the directing properties of the transition metals. In comparison, there are relatively few examples of assemblies that were designed to use the main group elements as directing components, showing that main group supramolecular chemistry is still developing the tools for the predictable formation of well-defined structures.

The main group elements generally prefer unusual “coordination” geometries compared to the transition metals, making them attractive targets when seeking novel properties, new topologies and alternative functionalities in self-assembled molecules and materials. However, there exists perhaps a misconception that bonds to main group elements are not labile enough for self-assembly. Contradictory to this belief, thiolate bonds shown to the Group 15 elements phosphorus, arsenic, antimony and bismuth are sufficiently reversible and can be used to drive the formation of supramolecular assemblies.

Full synthetic details and characterization of newAs2L3 and Sb2L3 cryptands are avaliable. There are many squemes that represents the ligands used in synthesis of cryptands, such as representations of the X-Ray crystal structures of As and Sb cryptands and chemical properties of them. Moreover, it could be find studies of X-ray diffraction, where we can obtain distances between atoms of the criptands, symmetries and angles.


Reference:

Fontenot et al. Design, synthesis and characterization of self-assambled As2L3 and Sb2L3 cryptands. Dalton Trans., 2011, 40, 12125

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