Syntheses of chiral fused 4,5-diazafluorene–bis(nopinane) derivatives

Reaction of fused 4,5-diazafluorene–bis(nopinane) with tere-phthalaldehyde, benzophenone, ninhydrin or anthraquinone in THF in the presence of TiCl₄ and pyridine results in a formation of new chiral condensation products, which exhibit solvatochromism and pleochroism. Crystal structure of the key products has been determined by X-ray crystallography, and unusual colour behavior has been explained by DFT calculations.