Hybrid interfaces in layered hydroxides: magnetic and multifunctional superstructures by design

This article is a critical review on layered hybrid organic-inorganic functional structures. We specially discuss a series of results concerning the design of magnetic and multiproperty systems derived from hybridization of layered transition metal hydroxides. A series of hybrid materials showing original magnetic properties are reviewed, which were prepared by functionalization of layered simple hydroxides (LSH) of the general formula M2(OH)3A (M=Co, Cu, Ni, Zn, … and A=NO3-, OAc-, alkylcarboxylates, peptides, metal complexes…). To make the point on this vast family of hybrid compounds, we present first the work investigating the mechanism of interaction and the structural factors influencing the magnetic properties of hybrid materials based on LSH. Then, we detail how even more complex anions can be immobilized and grafted into the interlamellar space giving rise to new functionalities. These systems are very good models for understanding the correlations between the structure of hybrid systems and the physical properties brought by the inorganic host and by the molecular moieties grafted onto the inorganic metal network. The interface between the organic and inorganic components, i.e. chemical bonding, charge density, or local pressure, is essential for the control of the properties of multifunctional hybrid systems. Some conclusions are drawn on the future of this approach, useful for developing new two-dimensional functional systems