New redox materials based on functionalized 9,10-anthracenediylidenes

The syntheses, electronic, optical and structural properties of a range of derivatives of 9,10-anthracenediylidene are described. The ®rst family of compounds are p-electron donors based on 9,10-bis(1,3-dithiol-2-ylidene)-9,10-dihydroanthracene. Recent synthetic developments are reviewed, including the functionalisation, via lithiation and subsequent in situ quenching with electrophiles, of the trimethyl derivative 8. X-Ray crystal structures of selected derivatives reveal that the molecules adopt a saddle-shaped conformation. The second family of compounds are novel single-component donor±p-acceptor species which possess intramolecular charge transfer, notably 10-(4,5-dimethyl-1,3-dithiol-2-ylidene)-9-(2,2dicyanomethylene)anthracene 19. Cyclic voltammetric data, UV/visible spectra, ultrafast time-resolved spectroscopy and X-ray structural data are reported.