Organic–inorganic hybrid materials: Metallacalixarenes. Synthesis and applications

•We report the synthesis and application of metallacalixarenes.•Metallacalixarenes possess magnetic and optical properties.•Metallacalixarenes are promising cations, anions and neutral molecule receptors.•Porous structures may adsorb N2 and/or H2and methanol/benzene vapors.

This review focuses on the synthesis and applications of organic–inorganic hybrid materials called metallacalixarenes. Two different subclasses of metallacalixarenes are presented: cyclic discrete oligomers based on heterocycles or nucleobases and metallacalixarenes as part of a polymeric network based on 1,3-dicarboxylate ligands. In addition to their potential application in gas adsorption/separations, magnetism and catalysis, metallacalixarenes might complex cations, anions, or neutral molecules due to their calixarene-like cavities.