Synthesis, Crystal Structure, and Inherent Chirality in Hexa(tertbutylphenyl)-Substituted [6]Cycloparaphenylene

Abstract

Herein, we report a [6]cycloparaphenylene ([6]CPP) derivative, [6]CPP-6tBuPh, in which peripheral substitution breaks the intrinsic symmetry of the nanohoop, giving rise to inherent molecular chirality with restricted phenylene rotation. The target molecule was synthesized via an Au-templated macrocyclization strategy and structurally characterized by NMR spectroscopy, high-resolution mass spectrometry, and single-crystal X-ray diffraction analysis. The racemic mixture of [6]CPP-6tBuPh was successfully resolved by chiral HPLC, and the isolated enantiomers exhibit mirror-image circular dichroism spectra.