Exploiting the use of multivalent interactions in the design of photoreactive supramolecular assemblies. From solution to crystal engineering

Abstract

Supramolecular assistance to covalent synthesis from [2+2] photoreactions either in solution or in the solid state is revised. A brief introduction and summary of emergent supramolecular approaches as alternative synthetic routes to prepare stereocontrolled cyclobutane derivatives are shown. The main part of this chapter covers the crystal engineering of photoreactive multi-component assemblies which have been studied in our group during this last decade. In particular, an examination of the use of ionic interactions and multivalent metal–ligand interactions based on the combination of hydrogen bonding and metal coordination as important and reliable alternatives for the design of novel photoactive supramolecular assemblies is discussed in detail. In addition, the mecanochemical method represents an attractive green route either for the self-assembly or improving the yield of photoreactions, likewise a non photochemical route for the regioselective preparation of new and conventional cyclobutane isomers that are difficult or impossible to access either from solution or by known solid state strategies based on the combination of topochemical reactions with hydrothermal methods is also presented.