A smart “Swiss-knife” dithiaaza[7]helicene electroactive tool: adding 3D push-pull features to inherent chirality and film electrodeposition ability

A new dithiaaza[7]helicene of remarkably multifaceted nature and functional properties is introduced and studied by comparison with a pool of simpler thia- or azahelicenes and related model molecules. Its helical conjugated backbone endows it with interesting spectroscopic and electrochemical features as well as with powerful inherent chirality. In addition, the new molecule has terminals of opposite character which endow it with push-pull features (along the backbone and across 3D space) as well as with a remarkable pool of functional properties: (i) an electron poor pyridine-based terminal, which can be involved in acid/base equilibria or enable conversion into molecular salts by alkylation; and (ii) an electron rich (benzodi)thiophene-based terminal, which allows reproducible electrodeposition of electroactive films, thus enabling to transfer the above pool of prop- erties from single molecule to nanostructured inherently chiral electroactive materials.