Combining porosity and magnetic ordering in a single material presents a significant challenge since magnetic exchange generally requires short bridges between the spin carriers, whereas porosity usually relies on the use of long diamagnetic connecting ligands. Despite this apparent incompatibility, notable successes have been achieved of late in generating truly microporous solids with high magnetic ordering temperatures. In this critical review, we give an overview of this emerging class of multifunctional materials, with particular emphasis on synthetic strategies and possible routes to new materials with improved properties (149 references).

Structural, spectroscopic and magnetic methods have been used to characterize the tris(carbene)borate compound PhB(MesIm)₃MnN as a four-coordinate manganese(iv) complex with a low spin (S = 1/2) configuration.

The design of molecule-based systems displaying tuneable optical and/or magnetic properties under external stimuli has received a great deal of attention in the past few years. This interest is driven by the potential applications in high-performance molecule-based electronics in the areas of recording media, switches, sensors, and displays. As an example, three-dimensional Fe/Co Prussian blue compounds exhibit a concomitant change in magnetic and optical properties due to a temperature- or light-induced metal-to-metal electron transfer. The foregoing remarkable properties in Prussian blues prompted us to design soluble molecular fragments of these coordination networks through a rational building-block approach in order to mimic their properties on a single molecule. With a judicious choice of the ligands for the iron and cobalt molecular precursors, we prepared a dinuclear cyanido-bridged Fe/Co complex that exhibits an unexpected temperature-dependent spin crossover in the solid state while an intramolecular electron transfer triggered by protonation is observed in solution.