Highly enantioselective “inherently chiral” electroactive materials based on a 2,2' -biindole atropisomeric scaffold

Chiral oligothiophene monomers with C2 symmetry, based on 3,30
-bithiophene atropisomeric cores with
high racemization barriers, have recently been shown to provide excellent chiral starting materials with
high electroactivity for the easy preparation of enantiopure electroactive films endowed with powerful
chirality manifestations. We now introduce an inherently chiral monomer based on a 2,20
-biindole core,
as the prototype of a new inherently chiral monomer family, whose properties could be modulable
through functionalization of the pyrrolic N atoms. By fast, regular electrooligomerization the new
monomer yields inherently chiral films with high, reversible electroactivity and, above all, impressive
enantioselectivity towards very different chiral probes, some of pharmaceutical interest, as generalscope electrode surfaces. Such results, while opening the way to a new, attractive inherently chiral
selector class, nicely confirm the general validity of the inherent chirality strategy for chiral
electrochemistry. Furthermore, the enantioselectivity of the new selectors not only holds with
electroactive chiral probes, but also with circularly polarized light components as well as electron spins,
resulting in good chiroptical and spin filter performances, which suggests fascinating correlations
between the three contexts.