Loredana Preda

The cathodic behaviour of poly(alkyl) and (aryl) sulfones revisited. Mechanistic and theoretical approaches

A series of aromatic sulfones activated by 2, 3 or 4 sulfonyl groups were reduced electrochemically in aprotic media. The electrochemical behaviour is strongly directed by the nature and the number of the substituents bound to the aromatic ring. From the analyses of cyclic voltammetry experiments, the kinetics and thermodynamic parameters were evaluated for each system and a theoretical study at the B3LYP/6-31G* level was performed simultaneously to understand the reactivity of the radical anions stemmed from these aromatic sulfones.

Electrochemical study and MO — modeling of the reduction behaviour of some arylidene substituted derivatives of dibenz [b,e]-thiepin-5,5-dioxide-11-one

The electrochemical reduction of four arylidene substituted derivatives of dibenz-[b,e]-thiepin-5,5-dioxide-11- one has been studied by cyclic voltammetry on platinum (Pt) electrode in aprotic media (DMSO), coupled with spectral EPR techniques. From the analysis of cyclic voltammetry experiments, aided by digital simulations using DigiSim software, the kinetic and thermodynamic parameters were evaluated for each system. The electrochemical behaviour is strongly directed by the nature of the arylidene substituents bound to the central heterocycle. The electrochemical investigation and solvent dependent semiempirical modeling using the PM3 hamiltonian in the frame of AMPAC program package allowed a rationalisation of experimental data regarding the electrochemical reduction and the reactivity of the intermediate species involved.