Synthesis And Electrochemical Properties Of Phthalocyanine Rare Earth Complexes

Three series of bis(phthalocyaninato) rare earth compounds Ln(Pc)2, Ln[(CF3CH2O)4Pc]2 and Ln[Pc(OPhCOOC2H5)4]2(Ln=La, Pr, Nd, Sm, Eu, Gd, Tb, Dy, Er, Lu, Y), have been synthesized using standard Schlenk techniques under nitrogen in this paper. All as-synthesis compounds have been characterized by UV-Vis, IR and Element Analysis. The electrochemistry of compounds has been comparatively studied by cyclic voltammetry (CV) and differential pulse voltammetry (DPV) in dichloromethane containing tetra-n-butylammonium hexafluorophosphate. One quasi-reversible one electron oxidations and four quasi-reversible one electron reductions have been revealed for two series of substituted bis(phthalocyaninato) rare earth complexes, respectively. For comparison, the electrochemistry of the unsubstituted bis(phthalocyaninato) rare earth analogues Ln(Pc)2 has also been electrochemically investigated. One quasi-reversible one electron oxidations and up to five quasi-reversible one electron reductions have been revealed for these neutral double-decker compounds. The difference between the redox potentials of the second and third reductions for Ln(Pc)2, Ln[(CF3CH2O)4Pc]2 and Ln[Pc(OPhCOOC2H5)4]2, which represents the energy gap between HOMO and LUMO,gradually diminishes along the lanthanide contraction, indicating lanthanides enhancedπ-πinteractions in the double-deckers. The half-wave redox potentials of the compounds Ln[(CF3CH2O)4Pc]2 and Ln[Pc(OPhCOOC2H5)4]2 become more positive compared with unsubstituted Ln(Pc)2 and substituted bis(phthalocyaninato) rare earth analogues containing electron donated group, which makes compounds difficultly oxidation and easily reduction. Two series of phthalocyaninato rare earth compounds may become n-type semiconductor materials having a lurking applying value according to comparing the LUMO energy level.