Diastereoselective Scholl reaction: Point-to-helical chirality transfer in molecular nanographenes

Abstract

A stereoselective control of molecular nanographene helicity has been achieved by a point-to-helical chirality transfer during the Scholl graphitization reaction to obtain compound 4. Density Functional Theory calculations indicate that the complete diasteroselectivity of the process takes place mainly under kinetic control. Circular dichroism and circularly polarised luminescence studies of both enantiomers show the expected mirror images, with a dissymmetry factor (g_lum) value determined at 470 nm of 1,0 × 10⁻³ and a remarkable circularly polarized luminescence brightness (B_CPL = 4,9 M^-1cm^-1).