Linear and Third‐Order Nonlinear Optical Properties of Triazobenzene‐1,3,5‐triazinane‐2,4,6‐trione (Isocyanurate) Derivatives

The synthesis of three new isocyanurate derivatives 2-X (X=NO2 , H, NMe2 ) with azobenzene arms terminated by various X substituents is reported, and their linear and nonlinear absorption properties are studied. It is shown that mixtures that contain increased contents of cis-azo isomers can be reversibly generated upon photoirradiation at specific wavelengths from the most stable all-trans isomers with X=NO2 and H. In addition, we show that 2-X derivatives are two-photon absorbers with cross-section maxima around 120 GM for 2-NO2 , thus indicating that trans-to-cis isomerization might be achievable by two-photon excitation, whereas the photoinduced structural changes should have only a modest influence on these nonlinear absorption properties.