Preparation and Electrochemical and Optical Properties of α ‐Alkoxyphthalocyanines with β ‐Pyridylthio Groups

Preparation and Optical and Electrochemical Properties of Boron (III) Octafluorosubphthalocyanines with One Triselenole and One Diselenet Ring

Unsymmetric boron (III) subphthalocyanines with a triselenole ring or a diselenete ring and eight fluoro groups were prepared by the reaction of 5,6-dicyano-4,7-diethylbenzo-[1,2,3]triselenole and tetrafluorophthalonitrile with trichloroborane in xylene. The reaction was accompanied by a contraction of the triselenole ring to the diselenete ring. The substrate, dicyanobenzo[1,2,3]triselenole, was prepared by a new procedure via a photolytic demethylenation reaction of 3,7-diethyl[1,3]diselenolophthalonitrile using a 10 W white LED light. While triselenolosubphthalocyanine was treated by triphenylphosphine to give the diselenete derivative, the reaction of diselenetosubphthalocyanine with Woolion's reagent produced the expanded triselenole ring. The diselenete derivative reacted with tetrakis(triphenylphosphine)platinum to yield the corresponding platinum complex with Se-Pt bonds. Q-band absorption for the products appeared at around λmax=590 nm in the UV-vis spectrum and weak emission was observed at about λe=620 nm. When diselenetosubphthalocyanine was treated with pentachloro antimonate in dichloromethane or sodium metal in hexane/tetrahydrofuran, the solution showed strong ESR signals. The structures of model compounds were optimized using the DFT method with the Gaussian 09 program at the B3LYP/6-31G (d, p) level.

α- and β-Substituted Metal-Free Phthalocyanines: Synthesis, Photophysical and Electrochemical Properties

Two novel phthalonitrile derivatives, bearing two hexyloxy groups and a benzodioxin (or a naphthodioxin) annulated ring, along with their corresponding metal-free phthalocyanines (H2Pc) were prepared. FT-IR, mass, electronic absorption, 1H NMR, and 13C NMR spectroscopy were employed for the characterization of all compounds. The effect of hexadeca substituents on the photophysical properties of metal-free Pcs was investigated. Photophysical properties of H2Pc were studied in tetrahydrofuran (THF). Fluorescent quantum yields of phthalocyanines (Pcs) were calculated and compared with the unsubstituted phthalocyanine. 1,4-Benzoquinone effectively quenched the fluorescence of these compounds in THF. Cyclic and square wave voltammetry methods were applied to metal-free phthalocyanines and Pc-centered oxidation and reduction processes were obtained.