Progresses Of Photochromic Materials

Chromic materials are one of well-known applicable functional materials and have been paid much attention for the inorganic, organic and material chemists. In this field, the photochromic materials have shown important applications in energy-transfer, displaying device, building and vehicle glasses. Many organic photochromic materials exhibit excellent molecular decoration and clipping properties, however, their stability and consistence properties are obvious disadvantages. Transition metal-substituted polyoxometalates represents one kind of inorganic photochromic materials with various structural topologies and excellent photo-, electro- and magnetic properties. However, such inorganic materials are also difficult to control the size, shape and physiochemical properties according to the practical requirement. Thus, the combination of inorganic and organic photochromic materials together to form a new hybrid materials containing the excellent properties of both parts become one big challenge and important topic. Based on various weak intermolecular interactions, the polyoxometalates can be embedded into various organic components to form new inorganic-organic hybrid materials, which can combine the properties of both inorganic and organic counterparts into one composite material, and can more easily operate and apply into various new functional materials, exhibiting extensive application perspective.In this thesis, we have reviewed the recent research progress of organic and inorganic chormic photochromic materials, especially focused on the polyoxometalate-based photochromic materials and described the progress of this research field, predicted the possible developing trend. In several photochromic systems, we have well described the history, chromic principle and developing trends of metal oxide-based and polyoxometalate-based photochromic materials.