Synthesis, electrochemical and intramolecular charge-transfer properties of ‘calix[4]arene-acceptor’ diad and triad derivatives

Calix[4]arenes substituted with various acceptor moieties (naphthoquinone (NQ), tetracyanoanthraquinodimethane (TCNAQ)) have been synthesized. In these derivatives the three-dimensional structure of calix[4]arene acts as a weak electron donor (D), connected via a linear sigma spacer to one or two electroactive acceptor (A) units. The electrochemical behavior of these derivatives has been studied by cyclic voltammetry. The UV–Vis spectrum of the TCNAQ triad (A–D–A, ) reveals the presence of a weak intramolecular charge transfer absorption band.