The synthesis of bis(2,4,6-trihalophenolato)di/or mono(pyridine)nickel(II) complexes and their characterisation by FT-IR, DSC and elemental analysis were achieved. The polymerisation of these complexes was accomplished in potassium perchlorate solution in N,N-dimethylformamide by constant potential electrolysis, at room temperature. The structural analysis of the polymers was performed using FT-IR, H-1-NMR and C-13-NMR spectroscopic techniques, DSC for the thermal analysis and molecular weight by GPC. The kinetics of the polymerisations were followed by in situ UV-VIS spectroscopy, during the constant potential or constant current electrolysis in two different solvents. The mechanism of the polymerisation was investigated by in situ ESR spectroscopy. There was no induction period for the polymerisation during electrolysis. (C) 2001 Elsevier Science Ltd. All rights reserved.