Formation of 1,2,4-trioxolanes via 9,10-dicyanoanthracene(DCA)-sensitized photo-oxygenation of 2,2-diaryl-3-(2,2-diarylvinyl)oxiranes

9,10-Dicyanoanthracene-sensitized photo-oxygenation of 2,2-diaryl-3-(2,2-diarylvinyl)oxiranes 3 in acetonitrile did not afford the corresponding 1,2,4-trioxepines 4, but 1,2,4-trioxolanes 7. The structural assignment of 7 was reported, and the mechanism of the formation of 7 was proposed.     

Phase diagram of the SrS–Ga2S3 system and its application to the single-crystal growth of SrGa2S4

Ce-doped SrGa₂S₄ compound is expected as a new host material of blue EL devices. However, the basic properties of bulk single crystals have not been fully clarified, since this compound has been mostly synthesized in the form of polycrystals or thin films. Here, we firstly present the pseudo-binary phase diagram of the SrS–Ga₂S₃ system constructed in accordance with our DTA data for single-crystal growth of SrGa₂S₄. It is shown that SrGa₂S₄ compound has a congruent melting point and a eutectic reaction in the side of excess of Ga₂S₃ concentration. On the basis of the phase diagram, single crystals of SrGa₂S₄ are grown using Ga₂S₃ as a self-flux in a horizontal Bridgman furnace. Colorless and transparent crystals having a typical size 2×2×2 mm³ are obtained.     

Use of naphthalene as a solvent for selective formation of the 1:1 diels-alder adduct of C60 with anthracene

A reaction of C₆₀ with an equimolar amount of anthracene in refluxing naphtlhalene gives the 1:1 Diels-Alder adduct in 67% yield based on consumed C₆₀: the adduct was fully characterized by IR, UV-vis, ¹H and ¹³C NMR, and MS spectroscopy, and exhibited reversible reduction waves at the potential 0.11 to 0.19 V more negative and an irreversible oxidation peak at the potential 0.11 V less positive than those of C₆₀ itself.     

Search for sleptons and squarks at the Z0 peak in e-e+ colliders

We investigate single scalar lepton and scalar quark production processes $\text{e}{}^{\mathrm{-}}\text{e}{}^{\mathrm{+}}\text{→ Z}{}^0\text{→}\text{?}{}^{\mathrm{\pm }}\text{γ}\text{?}{}^{\mathrm{\pm }}\text{,}\text{q}\text{γ}\text{q}\text{and}\text{q}\text{g}\text{q}$ at the Z⁰ peak. We find that a detectable number of these scalars should be produced at the SLC and LEP-I colliders even if their masses substantially exceed the beam energy E = m_Z/2?45 GeV.     

Lewis base catalyzed ring opening of aziridines with silylated nucleophiles

The ring opening of N-tosylaziridines with trimethylsilylated nucleophiles, catalyzed by N,N,N',N'-tetramethylethylenediamine, led to the production of beta-functionalized sulfonamides in good to excellent yields with high regioselectivity. [reaction: see text]     

Synthesis of protoheme IX derivatives with a covalently linked proximal base and their human serum albumin hybrids as artificial hemoprotein

The simple one-pot reaction of protoporphyrin IX and omega-(N-imidazolyl)alkylamine or O-methyl-L-histidyl-glycine with benzotriazol-1-yl-oxytris(dimethylamino)phosphonium hexafluorophosphate at room temperature produced a series of protoporphyrin IX species with a covalently linked proximal base at the propionate side-chain. The central iron was inserted by the general FeCl2 method, converting the free-base porphyrins to the corresponding protoheme IX derivatives. Mesoporphyrin IX and diacetyldeuteroporphyrin IX analogues were also prepared by the same procedure. The Fe(II) complexes formed dioxygen (O2) adducts in dimethylformamide at 25 degrees C. Some of them were incorporated into the hydrophobic domain of recombinant human serum albumin (rHSA), providing albumin-heme hybrids (rHSA-heme), which can bind and release O2 in aqueous media (pH 7.3, 25 degrees C). The oxidation process of converting the dioxygenated heme in rHSA to the inactive Fe(III) state obeyed first-order kinetics, indicating that the mu-oxo dimer formation was prevented by the immobilization of heme in the albumin scaffold. The rHSA-heme, in which the histidylglycil tail coordinates to the Fe(II) center, showed the most stable O2 adduct complexes.