New photoactive D-π-A-π-D benzothiadiazole derivative: Synthesis, thermal and photophysical properties

A new fluorophore containing a 2,1,3-benzothiadiazole unit containing alkylated tetrazoles terminal groups as electron donors connected through pi-conjugated system of type D-pi-A-pi-D was synthesized and electronically and electrochemically characterized. The compound in solution has an absorption maximum in the visible region (similar to 417 nm) due to electronic transitions of type (1)pi pi* (epsilon similar to 10(4) M-1 cm(-1)) and intense fluorescence emission (Phi(F) similar to 0.65) located in the blue-green region depending on the solvent used with a Stokes' shift of ca. 75 nm. Evidences of intramolecular charge transfer character in the excited state was observed from the Lippert Mataga correlation. The AFM images of the spin-coating depositions of compound 9 using chloroform as solvent on silicon substrate showed the formation of films with clusters. AFM images of the deposition of the acrylic thermoplastic resin doped with 0.05% of 9 showed the formation of a uniform, low-roughness film. Fluorescence emission was shown to be dependent on the method used for the formation of the films. (C) 2015 Elsevier Ltd. All rights reserved.