Synthesis of Phosphine Oxide-Carboxylic Acid Esters Bearing 9,10-Dihydro-9,10-ethanoanthracene Moiety

A bulky type of phosphine oxide-carboxylic acid bearing 9,10-dihydro-9,10-ethanoanthracene moiety was synthesized by the Diels-Alder reaction of 2-anthryldiphenylphosphine oxide and methyl acrylate, for which the structure was confirmed on the basis of 1 H NMR spectral data to be dimethyl 2-diphenylphosphinoyl-9,10-dihydro-9,10-ethanoanthracene-11,11- and 12,12-dicarboxylates.     

Synthesis of Novel Sulfobetaine-Type Adsorbents and Characteristics of Their Adsorption of Polar Solutes in Hydrophilic SPE

A novel hydrophilic adsorbent was synthesized by introducing a sulfoethylbetaine functional group to a methacrylate base resin. The physical properties of the adsorbent were measured by NMR and IR spectroscopy and acid–base titration. The results indicate that (1) the positive and negative charges of the adsorbent are in balance when a purified sulfobetaine reagent is used, (2) the amount of water in the first hydration layer is about 6.7% of the adsorbent mass when the adsorbent is in an aqueous solution with a high acetonitrile content, and (3) the sulfobetaine functional group is covalently bonded to the base resin through a tertiary amino group. The retention properties of hydrophilic solutes on the adsorbent were estimated by the solid phase extraction method. All ionic reference solutes such as nucleobases (uracil, adenine and cytosine), acids (acephate and levulinic acid) and zwitterions (tetracyclines) were entrapped and released by the adsorbent. However, it showed almost no retention for non-ionic polar solutes such as saccharides. The polar solutes retained on the adsorbent could be easily eluted by water except for levulinic acid and tetracycline, which are easily ionized.

     

Photocatalytic Decomposition of Acetaldehyde with Anatase Nanocrystals-Dispersed Silica Films Prepared by the Sol-Gel Process with Hot Water Treatment

Anatase nanocrystals of 5 to 10 nm in diameter were formed in the silica-titania films by treatment with hot water. The formation of nanocrystals with hot water treatment was a unique phenomenon to the silica-titania system and the addition of organic polymers such as PEG was indispensable for the high dispersion of anatase nanocrystals in the films. The hydrolysis of Si—O—Ti bonds with hot water was considered to play an important role for the formation of anatase nanocrystals. The resultant films were transparent even after the formation of anatase nanocrystals. Acetaldehyde was photocatalytically decomposed into CO₂ on the films which were subjected to a hot water treatment. The amounts of generated CO₂ were twice of that of introduced acetaldehyde, indicating that the total acetaldehyde was completely decomposed to CO₂. Anatase nanocrystals-dispersed films can be formed on various kinds of substrates including those with poor heat resistance such as organic polymers and organisms by this process, so that the substrates coated with the films are expected to be widely used for photocatalytic applications.     

Manganese‐based transition metal complexes as new catalysts for olefin polymerizations

Three manganese complexes, Mn(acac)₃ (acac = acetylacetonate), Cp₂Mn (Cp = cyclopentadienyl), and Mn(salen)Cl [salen = 1,2‐cyclohexanediamino‐N,N′‐bis(3,5‐dit‐butyl‐salicylidene)], were used for ethylene and propylene polymerizations. These complexes, in combination with an alkylaluminum cocatalyst such as methylaluminoxane (MAO) or diethyl aluminum chloride (AlEt₂Cl), could promote ethylene polymerizations that yielded extremely high molecular weight linear polymers, but were inactive for propylene polymerizations. The counterparts supported on MgCl₂ showed activities even for propylene polymerizations and had remarkably enhanced activities for ethylene polymerizations. In the presence of an electron donor such as ethylbenzoate, the MgCl₂‐supported manganese‐based catalysts yielded a highly isotactic polypropylene with a high molecular weight. © 2001 John Wiley & Sons, Inc. J Polym Sci Part A: Polym Chem 39: 3733–3738, 2001     

Synthesis of A New Terpyridine Ligand Combined with Ruthenium(II) Complex and its Usage in the Stepwise Fabrication of Complex Polymer Wires on Gold

Summary: A ruthenium complex-combined terpyridine ligand, tpyRu(dpp)-(epe)- tpyPF₆, was synthesized. Stepwise coordination reactions at the gold surface using this ligand gave Co-Ru hetero-metal complex wires, [ 1Co1Ru ], which underwent reversible redox reactions of both redox complex units.     

Effect of spin contamination error on surface catalytic reaction: NO reduction by core-shell catalysts

ABSTRACT

The effects of spin contamination errors on the activation barriers of catalytic NO reduction by TiO₂/Ag and ZrO₂/Cu core-shell catalyst models were investigated using an approximate spin projection method and an unrestricted density functional theory calculation with the plane-wave basis set. The estimated barrier of the TiO₂/Ag system increased (0.03?eV), whereas that of the ZrO₂/Cu system decreased (0.04?eV) after the correction of the spin contamination error. This difference in the estimated barriers of the two systems can be attributed to the difference in their surface structures. The error obtained for the TiO₂/Ag system was larger than that obtained for the gas phase, i.e. the spin contamination error was induced by the molecule/surface interaction. Moreover, the error correction also changed the rate-determining step of ZrO₂/Cu. These results demonstrate the importance of the correction of spin contamination errors for the detailed investigation of catalytic reactions.