摘要：

Axially chiral, N -arylated 3,5-dihydro-4 H -dinaphtho[2,1- c :1,2- e ]azepines have been prepared by short synthetic protocols from enantiopure 1,1-bi(2,2-naphthol) (BINOL) and anilines. Alkynes substituted with two N -phenyldinaphthazepine donors readily undergo a formal [2+2] cycloaddition, followed by retro-electrocyclization, with tetracyanoethene (TCNE) to yield donor-substituted 1,1,4,4-tetracyanobuta-1,3-dienes (TCBDs) featuring intense intramolecular charge-transfer (CT) interactions. A dicyanovinyl derivative substituted with one N -phenyldinaphthazepine donor was obtained by a one-pot oxidation/Knoevenagel condensation from the corresponding propargylic alcohol. Comparative electrochemical, X-ray crystallographic, and UV/Vis studies show that the electron-donor qualities of N -phenyldinaphthazepine are similar to those of N,N -dimethylanilino residues. The circular dichroism (CD) spectrum of a push-pull chromophore incorporating the chiral donor moiety features Cotton effects of exceptional intensity. With their elongated shape and the rigidity of the chiral N -aryldinaphthazepine donors, these chromophores are effective inducers of twist distortion in nematic liquid crystals (LCs). Thus, a series of the dinaphthazepine derivatives was used as dopants in the nematic LC E7 (Merck) and high helical twisting powers ( ) of the order of hundreds of m-1 were measured. Theoretical calculations were employed to elucidate the relation between the structure of the dopants and their helical twisting power. For the derivatives with two dinaphthazepine moieties, a strong dependence of the -values on the structure and conformation of the linker between them was found.

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