Novel photo-switching using azobenzene functional materials

Azobenzene (azo) chromophores have been incorporated into a wide variety of materials and molecular architectures, including polymers, dendrimers, and molecular glasses. Azobenzene exhibits a uniquely clean and efficient photochemistry, with facile geometric isomerization about the azo bond, converting the molecule from trans to cis. This review discusses the extensive number of investigations of azobenzene photo-switching and photo-modulation. In particular, azos can be used to alter material behaviour with light, switching both molecular and macroscopic properties. A large number of photobiological studies have shown that interfacing the azo chromophore with enzymes and biopolymers is feasible and useful. The A-optical surface patterning unique to azobenzenes is also reviewed. Lastly, azobenzene photomechanical effects are discussed. (c) 2006 Elsevier B.V. All rights reserved.