First synthesis and electronic properties of cyano(oligo)phenothiazines

(Oligo)phenothiazinyl nitriles were synthesized in good to very good yields from bromo (oligo)phenothiazines via the Beller cyanation protocol either under conductive or under dielectric heating using NMP as a solvent. Their electronic properties were determined by absorption and emission spectroscopy and cyclic voltammetry. Cyano(oligo)phenothiazines display large Stokes-shifts (58008300 cm(-1)) and substantial quantum yields (11-27%). Their reversible oxidation potentials are considerably shifted anodically due to the electron-withdrawing character of the cyano group. (c) 2008 Elsevier Ltd. All rights reserved.