Environmentally friendly preparation of a conjugated polyazostilbene: A photophysical and electrochemical investigation

A novel polymer consisting of alternating azo and stilbene linkages was prepared by anodic electropolymerization via an environmentally friendly method. The green method deposits the polymer on a conductive and transparent ITO electrode resulting in a highly conjugated material exhibiting absorbances in the visible and in the near infrared regions. The polymer photoluminescence occurs at 478 nm similar to its stilbenedianiline analogue, while the Raman spectrum confirms the presence of the stilbene and the azo bonds. Transient absorption spectroscopy of the monomer by laser flash photolysis confirmed the triplet is produced upon irradiation concomitant with a radical cation. Laser irradiation also promotes isomerization of the trans isomer to the cis form confirming the monomer exhibits photodynamic properties.