Synthesis of Twisted Anthracenes: Induction of Twist Chirality by the Planar Chiral [2.2]Paracyclophane

Chem Asian J. 2022 Aug 1;17(15):e202200418. doi: 10.1002/asia.202200418. Epub 2022 Jun 10.

Abstract

Planar chiral [2.2]paracyclophane was employed as chiral scaffolds to twist an anthracene ring by tethering at its 1- and 8-positions; thus, twist chirality was induced in the anthracene moiety. The chiroptical properties of the resulting molecule, including circular dichroism (CD) and circularly polarized luminescence (CPL), were found to be derived from the twist chirality. An analogous molecule bearing long alkyl chains was a viscous liquid at ambient temperature, and its liquid film exhibited good CD and CPL profiles. Theoretical studies are carried out to determine the origin of these properties in the ground and excited states, which reproduced well the experimental results.

Keywords: [2.2]paracyclophane; circularly polarized luminescence; planar chirality; twisted acene; twisted chirality.