Effects of Donor and Acceptor Units Attached with Benzoselenadiazole: Optoelectronic and Self-Assembling Patterns

Abstract

Here, we report the effects of electron donor and acceptor units attached with benzoselenadiazole for the change in optoelectronic and packing patterns in solid states. We have synthesized 4-methoxybenzene, naphthalene, and 4-nitrobenzene capped benzoselenadiazoles (compounds 1-3 respectively) and studied their photophysical as well as electrochemical properties. All three molecules show two absorption bands (π-π transition band and CT-band). Three molecules (1-3) show orange, yellow-green, and green colors in dichloromethane solutions upon irradiation of UV light at 365 nm. Benzoselenadiazole-based compounds 1-2 form head to head dimers via Se···N interactions in the solid states. Compounds 1 and 2 show interlock type packing via Se···N interaction in their solid state structures. Se···π interaction takes a major role to form interlocked sheet type structures in crystal packing of compound 1, whereas Se···N, N···N, and CH···π interactions help to form a supramolecular sheet type of structure in the crystal packing of compound 2. Band gaps of these compounds were tuned by changing the electron donating to electron withdrawing units attached with a benzoselenadiazole core. © 2015 American Chemical Society.