Synthesis and fluoride-induced chemiluminescent decomposition of bicyclic dioxetanes substituted with a 2-hydroxynaphthyl group

Five bicyclic dioxetanes bearing a 2-hydroxynaphthyl group, 1aA-1eA, were synthesized and their chemiluminescent decomposition was examined by the use of tetrabutylammonium fluoride (TBAF) as a base in DMSO. It was found that these dioxetanes hold completely the ‘odd/even’ relationship between the substitution pattern of hydroxy as a trigger on the naphthalene ring and their chemiluminescent efficiency, and that dioxetane 1aA exhibited chemiluminescence with the highest efficiency among those for the oxynaphthyl-substituted dioxetanes hitherto known. The significant change in chemiluminescent efficiency depending on the substitution pattern was clarified to be attributed to the marked change in singlet-chemiexcitation efficiency for charge-transfer-induced chemiluminescence (CTICL) of 1aA-1eA. In respect of the rate of CTICL-decomposition, ‘odd/even’ relationship was observed for 1aA-1dA.     

Color modulation for intramolecular charge-transfer-induced chemiluminescence of bicyclic dioxetanes bearing a 3-hydroxy-5-naphthylphenyl moiety in the coordination sphere

Bicyclic dioxetanes 2a, 2b, and 3, bearing a 3-hydroxy-5-naphthylphenyl moiety underwent charge-transfer-induced decomposition with accompanying emission of light, the color of which changed from red to blue responding to a complex of crown ether with potassium t-butoxide used as a base. Furthermore, they afforded unusual chemiluminescence, the spectra of which displayed two peaks in some cases. It was observed for chemiluminescences in the coordination sphere with crown ether that their spectra did not coincide with the spectra of authentic emitters.     

A generalization of Lelieuvre’s formula to equiaffine immersions of general codimension

A non-degenerate equiaffine immersion of codimension one into an equiaffine space is locally expressed in terms of its conormal map and its affine fundamental form. The expression is called the Lelieuvre’s formula. We recently defined the notions of an equiaffine immersion of general codimension and its transversal volume element map. In this paper, we locally express a non-degenerate equiaffine immersion of general codimension into an equiaffine space in terms of its transversal volume element map and its affine fundamental form.     

Evaluating Optical Quality of a Bifocal Soft Contact Lens in Near Vision Using a Shack–Hartmann Wavefront Aberrometer

To assess optical characteristics of bifocal soft contact lenses (BCLs) in use, we measured wavefront aberrations of human eyes, of eyes with a monofocal soft contact lens (MCL), and of eyes with a BCL. Modulation transfer functions (MTFs), Strehl ratios, and simulated images for far and near vision were produced with the measured aberrations. High order aberrations of subject 1 were significantly smaller than those of subject 2 (t-test, P = 0.001). We found that wearing the BCL improved the optical quality of an eye in subject 1, expressed as the horizontal MTF from 2 to 48 cycles per degree (cpd) for near vision and the Strehl ratio (t-test, P = 0.009 for Strehl ratio). But we did not find the same effect in subject 2. This difference may be due to the difference in the aberrations of the eyes of the two subjects.     

Investigations of morphology, purity and crystal defects of the InN pillar crystals prepared by means of halide chemical vapor deposition under atmospheric pressure

Indium nitride prepared under atmospheric pressure using a halide chemical vapor deposition method has been examined by means of a variety of analytical techniques. Scanning electron microscopic observations showed that the crystals deposited onto a Si(100) substrate have hexagonal pillar structure. Based on the X-ray diffraction and X-ray pole-figure analyses, it was deduced that each InN pillar crystal grows with a different rotation angle around the 〈001〉 axis. Transmission electron diffraction showed that they are of single-like form. This was also confirmed by the selected area electron diffraction image as well.     

Asymmetric allylsilane-mediated carbocyclization: A highly enantiospecific synthesis of (1S, 2S)-(+)-2-methyl-3-cyclopenten-1-ol

An enantiospecific synthesis of the title compound is described which involves the TiCl₄-promoted cyclization of the chiral allylic silane having formyl group, which was obtained via the Claisen rearrangement of ($\text{R}$, $\text{E}$)-1-trimethylsilyl-1-buten-3-ol.     

Nitration of moderately deactivated arenes with nitrogen dioxide and molecular oxygen under neutral conditions. Zeolite-induced enhancement of regioselectivity and reversal of isomer ratios

In the presence of zeolites, moderately deactivated arenes such as 1-nitronaphthalene, naphthonitriles, and methylated benzonitriles can be smoothly nitrated at room temperature by the combined action of nitrogen dioxide and molecular oxygen. The regioselectivity is considerably improved as compared with the conventional nitration methodology based on nitric and sulfuric acids. In some cases, the minor isomer became favoured to a significant extent, resulting in the reversal of ordinary isomer ratios of nitration products.     

Isolation of the complex between acrylonitrile and trimethylaluminum

The complex of acrylonitrile (AN) with trimethylaluminum (AlMe₃) was successfully isolated as a white needlelike crystal with a melting point of 42.5°C. In this article the preparation of the complex is described in detail. Cryoscopic and spectral investigations indicated that the complex is formed by an equimolar ratio of AN and AlMe₃. From the measurement of the x-ray diffraction photograph of the crystal the repeat period was determined to be 9.47 ± 0.05 Å.