Département de chimie moléculaire

On the ground of advanced electrochem., spectroscopic and theor. data, we have demonstrated that two bipyridinium radicals introduced on the lower rim of a calixarene skeleton can be efficiently and reversibly pi-dimerized. A detailed electrochem. investigation supports the conclusion that the non-covalent assocn. between both electrogenerated radical-cations proceeds intramolecularly with a fast kinetics, the electrochem. behavior being mostly limited, in the accessible scan range, by the kinetics of the heterogeneous electron transfer. Further insights into the structure and stability of a series of covalently linked pi-dimers have been provided by DFT calcns. carried out at various computational levels. A major result of these theor. investigations is that solvents and dispersion-correcting potentials have to be considered to accurately model the non-covalent interactions involved in pi-dimer complexes. [on SciFinder(R)]