Bowl-to-bowl inversion of sumanene derivatives

The bowl-to-bowl inversion of the non-planar bowl-shaped compounds derived from sumanene as a fullerene C3v fragment was found to be slow and tuned by a solvent, and the benzylic mono- and di-anions inverted even more slowly.     

Preparation of highly photosensitizing liposomes with fullerene-doped lipid bilayer using dispersion-controllable molecular exchange reactions

Fullerene-containing liposomes with high photosensitization ability were prepared. Disaggregated fullerenes were efficiently injected into the bilayer of liposomes by a phototriggered molecular exchange reaction. These liposomes showed far higher photoreactivity than liposomes thermally produced by heating and microwave irradiation. This result indicates that control of self-aggregation of fullerene leads to a high quantum yield for the photoreaction because of the suppression of self-quenching of photoexcited fullerenes.     

Enzymatic resolution and evaluation of enantiomers of cis-5'-hydroxythalidomide

The straightforward synthesis of both enantiomers of cis-5'-hydroxythalidomide, a major metabolite of thalidomide, has been accomplished by enzymatic kinetic resolution of a racemic substrate catalyzed by Pseudomonas stutzeri lipase TL. cis-5'-Hydroxythalidomide shows resistance to racemization (and epimerization) at physiological pH. A tube formation assay to assess the ability to inhibit angiogenesis revealed that cis-5'-hydroxythalidomides are inactive.     

Regeneratively mode-locked fiber laser with a repetition rate stability of 4.9x10-15 using a hydrogen maser phase-locked loop

We demonstrate an ultrastable regeneratively mode-locked fiber laser that employs a phase-locked loop (PLL) circuit with a hydrogen maser. The stability for an integration time of 1s was 6.2x10(-13), which is 16 times better than that of a conventional PLL laser. For an integration time of 1000s, the stability reached as high as 4.9x10(-15). The repetition-rate stability was limited by the synthesizer used for the PLL operation, and there was no additional fluctuation induced by the laser operation.     

Formation of cage-like hollow spherical silica via a mesoporous structure by calcination of lysozyme-silica hybrid particles

Calcination of lysozyme-silica hybrid hollow particles gives novel cage-like hollow spherical silicas with differently patterned through-holes on their shell structure.     

Solubility of GaN in supercritical ammonia with ammonium chloride as a mineralizer

The solubility of GaN in supercritical ammonia with ammonium chloride as a mineralizer was measured with a weight-loss method. Temperature-, pressure-, and mineralizer concentration-dependence of the solubility of GaN were investigated. The solubility increased with increase in temperature, and its pressure dependence was very low. The solubility behavior was quite different from the case of using the mineralizer KNH₂ as a basic mineralizer.     

Biodegradation of aliphatic polyesters soaked in deep seawaters and isolation of poly(?-caprolactone)-degrading bacteria

To investigate biodegradability of so-called biodegradable plastics in deep sea, degrading behavior of aliphatic polyesters poly(?-caprolactone) [PCL], poly(β-hydroxybutyrate/valerate) [PHB/V], and poly(butyrene succinate) [PBS] in deep seawaters were evaluated at Rausu, Toyama, and Kume, Japan. After 12 months of soaking in deep seawaters, PCL and PHB/V fibers became brittle or completely ruined. Although breaking strength of PBS fibers maintained approximately 95% of the initial values, for all 3 fibers, many pinholes and cracks were observed on the surfaces. These results imply that examined 3 aliphatic polyesters are degradable also at deep sea though the degradation rates would vary with the material structures. From the deep seawaters assessed, 5 PCL-degrading bacteria were isolated, which were found to belong to the genuses Pseudomonas, Alcanivorax, and Tenacibaculum, as assessed by phylogenetic analysis using 16S rRNA gene sequencing. It was also confirmed that all these bacteria degrade PCL fibers in vitro. In addition, these strains were found to prefer conditions of low temperature (4-10 °C) and high hydrostatic pressure.     

Rare direct imidation of aromatic metallacycle by reaction of CpCo(dithiolene) complex with N-halosuccinimide

The aromatic [CpCo(S₂C₂(R)(H))] (R = Ph, Me, 9-phenanthryl, H) complexes reacted with N-halosuccinimides (NXS; X = Cl, Br, I) in carbon tetrachloride at room temperature to undergo the N-succinimide substitution reaction on the dithiolene ring, but no halogenated dithiolene complex was obtained. The imidation products [CpCo(S₂C₂(R)(N-sccinimide))] were yielded up to 64% where X = I and R = 9-phenanthryl. The reaction of [CpCo(S₂C₂(Ph)(H))] with N-bromophthalimide (NBP) also gave the imidation product [CpCo(S₂C₂(Ph)(N-phthalimide))]. This is the rare direct imidation reaction to an aromatic metallacycle by NXS. The reaction of [CpCo(S₂C₂H₂)] (R = H) with NIS afforded the double imidation product. One by-product in this reaction was the dithiolene-dithiolene homo-coupling product [CpCo(S₂C₂(R))]₂ (R = Ph, Me, 9-phenanthryl). The microwave-enhanced (MW) reactions were attempted in the carbon tetrachloride solution. Although the solution temperature increased up to only 43 °C by MW irradiation, the imidation reaction worked with short reaction time.