The two N atoms in Benzothiadiazole could possibly form intermolecular hydrogen bonding, leading to a more planar backbone. Benzothiadiazole is a strong electron-accepting molecular fragment. By fusing it with thiazole donor-acceptor dyes, near-infrared fluorescence was created. The benzothiadiazole ring is a useful n-type building block for designing electron-transport materials for organic and polymer light-emitting diodes (LEDs). Arene- and heteroarene-fused thiadiazoles have also found use in the design of low-band-gap materials for the construction of organic field-effect transmitters (OFETs), as stable organic radicals, and as one or two photon-absorbing materials for the design of nonlinear near-infrared (NIR) dyes. Benzothiadiazoles acting as the electron-accepting cores have been incorporated into dendrimer-type light-harvesting materials.
The imidazothiazole, consisting of an imidazole ring fused with a thiazole ring, has been reported to have excellent immunostimulating and anti-inflammatory activities. Fused heterocyclic compounds are of great importance and are found in various types of synthetic and naturally occurring biologically important compounds. Imidazothiazoles and imidazopyridines possess a variety of applications such as dyes, pesticides, fungicides, antitumor, antiinflammatory, and analgesic activity.