Assembly and Photoinduced Organization of Mono- and Oligopeptide Molecules Containing an Azobenzene Moiety

Assembled systems consisting of an azobenzene moiety as the photofunctional component and valyl units as the network backbone are investigated. The molecular ordering of these assemblies is examined by spectroscopy and theoretical calculations. The number of valyl units greatly influences the molecular order in the organized systems. Only N‐(L‐valyl‐L‐valyl‐L‐valyl)azobenzene‐4‐carboxamide (3) forms a complete β‐sheet structure in this artificial assembly. Upon photoirradiation, the azobenzene moieties isomerize completely, revealing the reversibility in the structural organization through the flexibility of the β‐sheet network in this system. A molecular system capable of organizing and dispersing upon exposure to different wavelengths of light is prepared by using an azobenzene derivative having three valyl moieties (see figure and cover). N‐(L‐valyl‐L‐ valyl‐L‐valyl)azobenzene‐4‐carboxamide forms a β‐sheet structure in this artificial assembly. Upon photoirradiation, the azobenzene moieties isomerize completely, and the reversibility of the structural organization through the flexibility of the β‐sheet network is revealed.