The crystal structures of many spin crossover solids have intricate architectures consisting of spin-active complexes as well as spin-inactive components, such as counterions and solvent molecules. The latter components undergo temperature induced ordering, in parallel with the spin conversion. This phenomenon has been observed experimentally by X-ray diffraction for compounds with disordered solvent molecules, counterions, and ligands. The structural data illustrating this phenomenon will be shown together with discussion of theoretical approaches mapping various ordering scenarios.
Swiss-Norwegian Beam Lines at the ESRF, BP 220, F-38043, Grenoble CEDEX, France