A Molecular Design towards a Highly Amphoteric and Polar Molecule (HAPM) to Assemble Novel Organic Solid-State Structures (INTERFACE SCIENCE-Molecular Aggregates)

Abstract To approach a novel molecular assembly with notable electronic properties, a molecular design towards highly amphoteric and polar molecules (HAPMs) as its building blocks is proposed. This design stresses the combination of two different π-molecular segments, electron-donating and accepting ones, particularly with a pseudo-delocalized π-election system. To examine the suggested contrivance, 2-(4-dicyanomethylenecyclohexa-2,5-dienylidene)-4,5-ethylenedithio-1,3-dithiole 1 was designed and synthesized as a test molecule. Semiempirical MO calculations of 1 and its extended quinonoid analogues indicate a moderately strong intramolecular charge-transfer working in the molecules in the ground state. Moreover, several experimental results of 1, e.g., its absorption spectra and cyclic voltammograms, imply that most characteristics expected for HAPM are in principle recognized in 1, though further improvements needed to clear the whole requirements for it.