The syntheses, spectroscopic and electrochemical properties of manganese (3), nickel (4) and iron (5) phthalocyanine complexes, octa-substituted at the peripheral positions with diethlyaminoethanethiol substituent, are reported. The electrochemistry of these complexes and the corresponding cobalt complex (6) are reported, Complex 3 showed two reversible reduction couples attributed to the (MnPc-2)-Pc-III/(MnPc-2)-Pc-II (E-1/2 = -0.12 V versus Ag vertical bar AgCl) and (MnPc-2)-Pc-II/(MnPc-3)-Pc-II (E-1/2 = -0.82 V versus Ag vertical bar AgCl) species. Two ring-based reduction couples were also observed for complex 4. Two reduction couples, assigned to the (FePc-2)-Pc-II/(FePc-2)-Pc-I (E-1/2 = -0.35 V versus Ag vertical bar AgCl) and (FePc-2)-Pc-I/(FePc-3)-Pc-I (E-1/2 = -0.96 V versus Ag vertical bar AgCl) species, and an oxidation couple, attributed to (FePc-2)-Pc-III/(FePc-2)-Pc-II (E-1/2 = 0.26 V versus Ag vertical bar AgCl) species, were observed. For complex 6, two reductions and one oxidation were also observed with the potential range of 1.2 to - 1.8 V versus Ag vertical bar AgCl Spectroelectrochemical studies were used to confirm some of the assigned processes. (C) 2009 Elsevier Ltd. All rights reserved