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The maintenance of life on earth, our food, oxygen, and fossil fuels depend upon the conversion of solar energy into chemical energy by biological photosyn-thesis carried out by green plants and photosynthetic bacteria. In this process sunlight and available abundant raw materials (water, carbon dioxide) are converted to oxygen and the reduced organic(More)
An electrooptical memory effect is observed with solid thin films of the photoconductor zinc-octakis(beta-decoxyethyl) porphyrin (ZnODEP) sandwiched between two optically transparent electrodes. Upon irradiation with the simultaneous application of an electric field, electron-hole pairs are generated and separated within the photoconductive layer. These(More)
Paired electron transfers (ET) induced by the absorption of two photons by synthetic dendrimers are observed in first-, second-, and third-generation dendrimers comprised of a viologen-like core and an array of naphthalene peripheral groups. Flash photolysis and transient absorption techniques show that the yield of photoinduced double ET depends on laser(More)
Styryl dyes 4a-e containing a 15-crown-5 ether unit and a quinoline residue with a sulfonatoalkyl or sulfonatobenzyl N-substituent were synthesized. The relationship between the photochemical behavior of these dyes and their aggregates derived from complexation with Mg(2+) in MeCN was studied using (1)H NMR and absorption spectroscopy. The E-isomers of 4a-e(More)
The synthesis and characterization of a group of new dendrimers-namely, nanoparticle-cored dendrimers (NCDs)-are described. These materials were obtained by the reduction of hydrogen tetrachloroaurate phase-transferred into toluene in the presence of Fréchet-type polyaryl ether dendritic disulfide wedges of generation 1-5. These materials, possessing(More)
A family of ruthenium coordination compounds capped by 4,4'-dimethylbipyridine ligands bearing 0, 1, 2, and 3 generations of dendritic phenothiazine moieties exhibit size-dependent electrochemical properties and structure-dependent absorption and luminescence spectra. Emission quantum yields, photoluminescence decay kinetics, and transient absorption(More)
Highly monodisperse water-soluble shell-core hybrid gold nanoparticles were prepared by in situ reduction of gold salts in the presence of a bifunctional thiol, tiopronin. The resulting particles exhibited diameters of 20-60 nm, as characterized by scanning electron microscopy. The tiopronin coating was uniform, exposing a carboxylated monolayer surface(More)
The synthesis and characterization of nanoparticle-cored dendrimers (NCDs), consisting of a metal core capped by arylpolyethers terminated with ester or carboxylate groups, are reported. These NCDs, comprising nanometer-sized gold clusters at the core and organic dendrons radially connected to the gold core by gold-sulfur bonds, were analyzed by TEM, TGA,(More)