Photochemically driven molecular switches may serve as motor units in future nanoscale machines. To design such motor units, we need to understand and improve the photochemical dynamics of molecular switches. In CRC 677, scientists from physical, organic and theoretical chemistry are working together towards this aim. In one of these research lines, the well-known molecular switch azobenzene could be improved significantly, by joining the two phenyl rings with an additional ethylenic bridge. With advanced methods of physical and theoretical chemistry, working hand in hand, it was possible to analyze the molecular movements on the femtosecond time scale and to fully understand the reasons for the improved photophysical properties of bridged azobenzene. In ongoing work, further improvements have already been achieved and embeddings of these new photochemical switches into complex molecular environments are studied.