Makoto Handa

Photocatalytic decomposition of trichlorophenol by zinc(II) phthalocyanine derivatives in aerated organic solvents

Abstract Trichlorophenol was photodecomposed by irradiation with visible light using zinc(II) phthalocyanine derivatives as a photosensitizer in aerated organic solvents. An oxidative quenching pathway via a generation of hyperoxide was proposed.

Catalytic oxygenation of olefin with dioxygen and tetra-t-butylphthalocyanine complexes in the presence of sodium borohydride

Abstract Catalytic oxygenation of styrene with dioxygen was performed by tetra-t-butylphthalocyanine complexes of manganese(III), iron(III), and cobalt(II) in the presence of sodium borohydride using ethanol as a solvent. The yield of 1-phenylethanol increased with the passage of time in the case of the manganese(III) and iron(III) complexes, but an induction period appeared in the case of the cobalt(II) complex. The initial reaction rate was 2.8 × 10−3 or 3.4 × 10−2 mmol min−1 for the reaction catalyzed by the manganese(III) or cobalt(II) complex respectively. No oxygenation product was formed in anaerobic ethanol with any of the complexes, but ethylbenzene was formed exclusively in the presence of the cobalt(II) complex. A radical scavenger, 2,2,6,6-tetramethylpiperidine-1-oxyl, inhibited the reaction considerably with the manganese(III) or iron(III) complex, but inhibited the reaction slightly with the cobalt(II) complex. The amount of oxygenation product from α-methylstyrene was larger than that from styrene in the case of the manganese(III) and iron(III) complexes, but the amount of oxygenation product from α-methylstyrene was almost the same as that from styrene in the case of the cobalt(II) complex. A radical mechanism is proposed for the oxygenation reaction of olefin catalyzed by the complexes. In the case of the cobalt(II) complex, a σ-bound intermediate may also contribute to the reaction.

Synthesis and Magnetic Property of Adducts of Ruthenium(II,III) Pivalate with 9,10-Anthraquinone

Abstract Reaction of tetrakis(pivalato)diruthenium(II,III) cation dimer and 9,10-anthraquinone (aq) gave two kinds of adducts, [{Ru2(piv)4(H2O)}2(aq)]-(BF4)2 (1) (pivH = pivalic acid) and [Ru2(piv)4(aq)] n (2), depending on the condition. Very weak antiferromagnetic interaction was observed for 1. The X-ray crystal structure of 2 shows an one-dimensional chain structure.

Dinuclear Phenoxo-Bridged Nickel(II) Complexes of Macrocyclic Ligands with Cyano Groups Laterally Introduced on a Conjugated System within the Ligands

Abstract Diphenoxo-bridged dinuclear nickel(II) complexes of macrocyclic ligands having two cyano groups laterally introduced on a π-conjugated system within the ligands have been prepared and characterized. The reaction solvent DMF is coordinated to the nickel(II) ions to cause them high spin state. The antiferromagnetic interaction (J = ca. -10 cm−1) was observed between the nickel(II) ions.

Coordination Polymers of Copper(II) and Copper(I) Trifluoroacetates with Pyrazine

Abstract New coordination polymers of copper(II) and copper(I), [Cu(tfa)2(pyz)2] n (Htfa = trifluoroacetic acid, pyz = pyrazine) (1), [Cu2(tfa)2(CH3O)2-(pyz)2] n (2), and [Cu2(tfa)2(pyz)3] n (3), have been synthesized and characterized structurally. The crystal structure of 2 consists of methoxo-bridged dinuclear copper(II) units which are connected by pyrazine molecules to form a two-dimensional network. The crystal structure of 3 shows a two-dimensional net-like structure, where each copper(I) atom has a distorted tetrahedral arrangement. The magnetic property of 2 is antiferromagnetic.

Determination of quenching process for the photoreduction of methyl viologen catalyzed by (sulfonatophthalocyaninato)zincate(II) in the presence of triethanolamine

Abstract Comparing an action spectrum for the photoreduction of MV 2+ in a three-component system of TEOA, the title complex, and MV 2+ with absorption and excitation spectra of the complex, a quenching process for the system was determined.