Chirality and Circular Polarized Properties of Photochromic Polyaromatic Molecules

Dihydropyrenes (DHPs) are a particularly interesting class of photochromic polyaromatic molecules due to their negative photochromism in UV-Vis spectra . Asymmetric heterocyclic-[e]-annelated DHPs were prepared by new synthetic routes and their photochromism was studied. The optical resolution of heterocyclic-[e]-annelated DHPs was performed by chiral HPLC systems and their enantiomers indicate the photochromism for UV-Vis, and CD spectra. The absolute structures of the enantiomers were determined by using spectra predicted with time-dependent density functional theory. Photoswitchable circular dichroism properties of asymmetric heterocyclic-[e]-annelated DHPs have potential as the molecular device to control the circular polarized light.