Inorganic Chromotropism Basic Concepts and Applications of Colored Materials

It was exactly twenty years ago (1987), when Professor Sone and I published a book "Inorganic Thermochromism" from Springer Verlag in which only the reversible color changes of the metal complexes due to temperature have been explained. During the past two decades, many interdisciplinary research works in the coordi- tion chemistry research field, and also in the science of colored materials, have been developed. Interdisciplinary research means that the universe of the respective research fields includes Inorganic, Organic, Material and Biochemical sciences and systems. But no book concerning the reversible color changes of the materials due to the outer stimuli has yet appeared. Then the idea of editing this book "Inorganic Chromotropism"was bom a few years ago. Many of these new works are of wide interest: among them, supramolecular self assembling systems which show char- teristic thermochromism in solution, magnetic properties of the metal complexes influenced by light (e. g. . Light Induced Excited Spin State Trapping phenomena on the spin crossover complexes) or metal complexes with photo sensitive ligand interaction and photo interaction of the molecular assembled systems are all dev- oping. The color changes of the complex systems due to outer stimuli are often observed, and some practical applications of the colored materials are also dev- oped. Chromotropism means the reversible color change of the colored materials due to the changes of chemical and physical environmental conditions, such as solvent, temperature, pressure, light or electrons.