COORDINATION OF THE TETRAKIS-PYRIDYL-PORPHYRIN TO THE FERRI-11-TUNGSTOPHOSPHATE - ELECTROCATALYTIC ACTIVITY OF THE COMPLEX IMMOBILIZED ON AGLASSY-CARBON ELECTRODE

The reaction of [Fe(H2O)PW11O39](4-) with tetrakis-pyridyl-porphyrin w as studied in solution. The formation of 1/1 and 4/1 complexes was sho wn by spectrophotometry. The 4/1 complex is also obtained by reaction of the heteropolyanion in solution with dhe cobalt-pyridyl-porphyrin p reviously adsorbed on a glassy carbon electrode. The complex is stabil ized at the surface of the electrode in the presence of cesium chlorid e. Study of the electrocatalytic reduction of dioxygen ar pH = 2 showe d thar the two-electron pathway observed with porphyrin alone is trans formed in a four-electron pathway. (C) Academie des Sciences/Elsevier, Paris.