Electrochemical coupling of phenyl halide catalyzed by NiCl2bpy in DMF has been investigated in this paper. Stainless steel was used as cathode and zinc as anode. Effects of potential, temperature and catalyst on electrolyses were studied to optimize the electrolytic conditions, with the maximal isolated yield under potentiostatic electrolysis to be 85%. Cyclic voltammetry of NiCl2bpy in the presence of phenyl bromide has been studied and mechanisms, concerned with several kinds of nickel complex, have been summarized.
Ionic liquid 1-ethyl-3-methylimidazolium bromide (EMIMBr) and N-methylimidazolium tetrafluorobo-rate (HMIMBF4) have been used as solvent and electrolyte for the electropolymerization of o-phenylenediamine at glassy carbon electrode by cyclic voltammetry. It was found that monomer was more easily oxidized in ionic liquid than acidic aqueous solution,and oxidative potential was reduced by 0.725 and 0.455 V,respectively. Electrode modified with poly(o-phenylenediamine) (PPD) has obvi-ous electrochemical activity in acid solution (pH 1-4). The apparent diffusion coefficient (Dapp) of PPD film is measured by chronocoulometry and chronoamperometry. The polymer structure is measured by UV and IR. IR spectrometry reveals that poly(o-phenylenediamine) has phenazine ring structure. The heat stability of polymer is observed from thermogravimetry.
The electrochemical reduction of CO2 on copper electrode was investigated in acetonitrile(MeCN),dimethyl formamide(DMF)and dimethyl sulfoxide(DMSO)containing 0.1 mol/L tetraethylammonium bromioe(TEABr)by cyclic voltammetry and chronocoulometry at 298 K and under atmospheric pressure.There were obviously irreversible one-electron reduction peaks after saturated with CO2 on copper electrode in three solvents,which generated anion radical of CO2.The influence of scan rate was also studied by cyclic voltammetry.The diffusion coefficients of CO2 in MeCN,DMF and DMSO were 8.981×10-6,1.019×10-6 and 1.032×10-6 cm2/s and the transfer coefficients were 0.064,0.042 and 0.059,respectively.These results show that the electroreduction of CO2 was an irreversible diffusion controlled process.
