Dimeric and Star‐Shaped Viologens: Synthesis and Capping interactions with β‐cyclodextrin

Abstract

Abstract Herein, we report the synthesis, characterization, inter‐and intramolecular complexation of branched viologen derivatives. Dimeric (DV), Trimeric (TV) and Star‐shaped (SV) viologen molecules bearing naphthyl periphery were successfully synthesized and characterized. Cyclic voltammetric studies shows that these derivatives undergo electrochemical reduction much easily at lower potentials than their corresponding dibenzyl analogues. Preliminary UV‐Vis investigations confirmed the formation of intramolecular CT (charge‐transfer) complexation between the chemically reduced monocation radicals in the case of o ‐xylylene interconnected dimeric viologen. Capping interactions with β‐CD (β‐Cyclodextrin) were studied by 1 H NMR techniques. Experiments in D 2 O showed the formation of inclusion complex (capping) between the terminal naphthyl groups and internal cavity of β‐CD via intermolecular hydrophobic interaction.