Synthesis and electronic properties of covalent assemblies of oligophenylenevinylene units arising from a calix[4]arene core

Assemblies of four oligophenylenevinylene moieties arising from a calix[4]a rene core, i.e., calix[4]-oligophenylenevinylenes, have been prepared by He ck-type cross-coupling reactions of styrene derivatives with a tetraiodinat ed cone-calix[4]arene precursor. Photophysical studies in solution have rev ealed that there are electronic ground state interactions between the coval ently bonded OPV moieties. The absorption spectra of the calix[4]oligopheny lenevinylenes are significantly different from those obtained by summing th e spectra of four model units and their emission is red-shifted when compar ed to the corresponding model compounds. Electrochemical studies have shown that the redox processes of the four OPV subunits do not take place at the same potentials indicating also a strong electronic interaction among them in the calix[4]oligophenylenevinylenes.