Abstract
Control of molecular dynamic processes represents a particularly important objective in modern chemistry. Azobenzenes are a class of organic compounds that can exist in two forms, namely the cis (Z) and trans (E) isomers, which can interconvert both photochemically and thermally. This photoinduced transformation is followed by a particular molecular movement and a significant geometry change, which has turned the azobenzene unit as an excellent candidate for dynamic molecular devices. In the present article selected examples of azobenzene-contained molecules and their "programmed" motions in response to external stimuli are included.