Dataset for Synthesis, Resolution, Configurational Stability and Properties of Cationic Functionalized [5]helicenes

A straightforward approach to the synthesis of two different series of cationic [5]helicenes has been achieved including, in dioxa series, the possibility to introduce aromatic functional groups at the periphery of the helical structure. While photo-physical study highlights that the introduction of aryl substituents at position 23 of the helical moieties has a negligible impact on the optical properties, styryl substituents allow a welcoming extension of the conjugation pathways. Finally, a red-shift of the optical properties was evidenced upon introduction of nitrogen atoms in the helicene scaffold, leading to particularly good fluorescence efficiencies in the red domain for a helicenic dye. Detailed information on racemization kinetics was collected for the most stable species upon direct HPLC resolution or, when configurational lability was too high, through VT-HPLC analysis on chiral stationary phase (ΔG‡ values ranging from 20.3 to 32.8 kcal.mol-1 and above