Peripheral and non-peripheral-designed multifunctional phthalocyanines; synthesis, electrochemistry, spectroelectrochemistry and metal ion binding studies

Abstract

A novel type of ionophore ligands, 3′-(2,3-dihydroxypropylthio)-phthalonitrile and 4′(2,3-dihydroxypropylthio)-phthalonitrile , and their α- and β-tetrasubstituted metallo phthalocyanines, (MPc), (M = Zn II, Co II, Mn IIICl, Fe IIIAc, Cu II) have been prepared and fully characterized by elemental analysis, FT-IR, 1H and 13C NMR, and MS (ESI and Maldi-TOF). The complexes are soluble in both polar and non-polar solvents, such as MeOH and EtOH, THF, CHCl 3 and CH 2Cl 2. The spectroscopic properties of the complexes are affected strongly by the electron-donating sulfanyl units on the periphery of the phthalocyanines. The cation binding properties of the complexes, for example using Ag I and Pd II, were evaluated by UV–Vis spectroscopy and the results show the formation of polynuclear phthalocyanine complexes. Functional donors on the periphery of the zinc and copper complexes coordinate to Ag I and Pd II to give ca. a 2:1 metal–phthalocyanine complex binding ratio for the concentration of 2.5 × 10 −5 M (Pc) and 1.0 × 10 −3 M (Metal ions). Voltammetric and in-situ spectroelectrochemical studies were performed to characterize the redox behavior of the complexes. An in-situ electrocolorimetric method was applied to investigate the colors of the electro-generated anionic and cationic forms of the complexes.