Ditopic Chiral Pineno-Fused 2,2′:6′,2″-Terpyridine: Synthesis, Self-Assembly, and Optical Properties

Abstract

The syntheses of 4′-substituted chiral 2,2′:6′,2″-terpyridine (tpy) ligands with predetermined configurations and directionalities are rather limited in the supramolecular chemistry field. In this study, a carbazole-linked ditopic chiral ligand L was synthesized using 4′-bromo-substituted pineno-fused tpy 5 as the precursor. Upon complexation with Cd(NO3)2·4H2O and Zn(NO3)2·6H2O, two enantiomerically pure metallosupramolecules, [Cd3L3] and [Zn4L4], have been self-assembled and characterized by NMR, electrospray ionization-mass spectrometry, traveling wave ion mobility-mass spectrometry, and DOSY analysis. In addition, their optical properties are characterized by UV–vis, fluorescence, circular dichroism, and circularly polarized luminescence, suggesting an efficiency transmission and amplification of chirality from the ligand to metal center via self-assembly.