Benzidine Type Electron Donors Fused with 1,2,5-Chalcogenadiazole Units

Abstract

The title electron donors (1 and 2) were prepared from 4-bromo-7-dialkylaminobenzo[c][1,2,5]thiadiazole (3). They are electrochemically amphoteric, and the absorption maxima in the 500-550 nm region were assigned to the intramolecular charge-transfer (CT) bands. The X-ray analyses of 1b and 1b +. PF 6 revealed that the twisted geometry of 1b became planar upon one-electron oxidation, and a coplanar «ribbon»-like network was formed by S...N interactions in the crystal of 1b +. PF 6