Dithienothiazine Copolymers – Synthesis and Electronic Properties of Novel Redox-Active Fluorescent Polymers

Abstract

Dithienothiazine copolymers are efficiently obtained by Suzuki polymerization or in situ lithiation-Negishi polymerization in good to excellent yields. Gel permeation chromatography was applied to characterize the dispersities and degrees of polymerization of these novel materials. Thermogravimetric analysis shows that the copolymers are stable towards sidechain cleavage up to 200 °C. The materials are deep red to black amorphous solids or resins and their absorption and emission spectra in solution reveal broad absorption bands in the visible and orange to deep red luminescence upon UV excitation. According to the optical band gaps these novel copolymers qualify as a new class of low band gap organic semiconductors.

Bis[1]benzothieno[1,4]thiaborins as a Platform for BODIPY Singlet Oxygen Photosensitizers

“…As the device performance ultimately originates from the molecular properties, the incorporation of electron-rich atoms such N, P or S emerged as an attractive method to modulate the electronic structure of the material. [12][13][14][15][16][17] For instance, electron-rich heterocycles such as phenothiazines [6,18,19] and their dithienyl congeners, namely dithieno [1,4]thiazines, [20][21][22][23] have attracted a of lot interest due to their low oxidation potentials and reversibility of the redox processes, as well as NIR luminescence. [24] Furthermore, the expansion of the dithieno [1,4]thiazines to the pentacyclic bis [1](benzothienylo) [1,4]thiazine (BBTT, Scheme 1) strongly favors luminescent behavior.…”