Limiting behavior of relative Rényi entropy in a non-regular location shift family

We calculate the limiting behavior of relative Rényi entropy between adjacent two probability distribution in a non-regular location-shift family which is generated by a probability distribution whose support is an interval or a half-line. This limit can be regarded as a generalization of Fisher information, and seems closely related to information geometry and large deviation theory.     

Synthesis of 2,4-disubstituted thiazoles from (Z)-(2-acetoxyvinyl)phenyl-lambda3-iodanes: nucleophilic substitution of alpha-lambda3-iodanyl ketones with thioureas and thioamides

In the presence of triethylamine, (Z)-(2-acetoxy-1-alkenyl)phenyl-lambda(3)-iodanes react with thioureas or thioamides in MeOH to give 2,4-disubstituted thiazoles directly in good yields. The reaction probably involves generation of highly reactive alpha-lambda(3)-iodanyl ketones through ester exchange of the beta-acetoxy group with liberation of methyl acetate, followed by nucleophilic substitutions with thioureas or thioamides.     

Solid state structures of pentacoordinated lambda3-iodanes with a trigonal bipyramidal geometry: synthesis of diphenyl- and alkynyl(phenyl)-lambda3-iodane complexes with 1,10-phenanthroline

The single crystal X-ray structure of the supramolecular complex formed between diphenyl-lambda3-iodane (Ph2IBF4) or 1-alkynyl(phenyl)-lambda3-iodane [Bu(t)CCI(Ph)BF4] and 1,10-phenanthroline indicates a hitherto unknown distorted trigonal bipyramidal geometry around iodine(III), in which 1,10-phenanthroline acts as a bidentate ligand and occupies equatorial sites.     

Synthesis and structure of supramolecular complexes between 1-alkynyl(phenyl)(tetrafluoroborato)-λ-iodanes and 18-crown-6

Slow evaporation of a solution of 1-decynyl(phenyl)(tetrafluoroborato)-λ³-iodane and 18-crown-6 in dichloromethane-diethyl ether-hexane gave a supramolecular 1:1 complex, while 3,3-dimethyl-1-butynyl- and phenylethynyl(phenyl)(tetrafluoroborato)-λ³-iodanes afforded 2:1 complexes. Complexation with 18-crown-6 increased the thermal stability of the phenylethynyl-λ³-iodane. Solid state and solution structures of these complexes were examined by single crystal X-ray analyses, ¹H and ¹³C NMR spectra, and cold-spray ionization MS. Binding constants were measured by ¹H NMR titrations.     

Stereoselective hetero Diels-Alder reaction of selenoaldehydes with pentavalent phosphole chalcogenides

Stereoselective hetero Diels-Alder reaction of selenoaldehydes, generated by thermal retro Diels-Alder reaction of anthracene cycloadducts, with pentavalent 3,4-dimethylphosphole chalcogenides at 110 °C in toluene to give the corresponding [4+2] cycloadducts as a single diastereoisomer in good yields, accompanied by a slight scrambling of chalcogen atoms. Higher reaction temperature led to an increase of the scrambling between chalcogen atoms.     

van der Waals layer-by-layer construction of a carbon nanotube 2D network

The acid-treated single-walled carbon nanotubes (SWCNTs) dispersed in water are only kinetically stable with electrostatic double layer repulsions just balancing against van der Waals (VDW) attractions. Introducing any external factor to disturb this balance causes immediate coagulation of SWCNTs. Here, an amine-covered flat substrate was immersed in the dispersion to initiate adsorption of SWCNTs onto the substrate surface. By repeating an adsorption-rinse-dry cycle, it was possible to deposit SWCNT bundles in a layer-by-layer fashion and to develop a 2D network consisting only of SWCNTs that are held by VDW interaction. We show that (1) adsorbed solution-grown aggregates are not relevant for the network connectivity, (2) 2D percolation takes place at very low surface coverage, (3) the electrical resistivity follows a power law against the layering cycles, (4) not only the adsorbed amount but also the added amount per layering cycle increases linearly with the SWCNT concentration, and (5) after the adsorption is initiated by amines, VDW attraction takes over for subsequent adsorption, with the consequence that the newly adsorbed SWCNTs are used to thicken each arm of the network rather than to cover more free surfaces.     

Preconcentration by dithiocarbamate extraction for determination of trace elements in natural waters by inductively-coupled plasma atomic emission spectrometry

Preconcentration by dithiocarbamate extraction into 2-ethylhexyl acetate for simultaneous determination of trace elements in natural water is described. After 250-fold concentration, the organic phase is used directly for inductively-coupled plasma atomic emission spectrometry. Thirteen elements (As, Se, Mo, Zn, Cd, Ni, Co, Sn, Fe, Cr(VI), Pb, V and Cu) are simultaneously concentrated at pH 4.3 with the combination of ammonium tetramethylenedithiocarbamate and dibenzylammonium dibenzyldithiocarbamate and are determined in the extract; Mn and Cr(III) are also determined after preconcentration at pH 6.9 with the same chelating agents. Lake waters are analyzed by this method.     

Diastereoselective alkylation and reduction of β-alkoxyacylsilanes: stereoselective construction of three contiguous stereogenic centers

The nucleophilic addition reaction to acylsilanes, having stereogenic centers at the α and β positions, derived from the aldol reaction of dimethyl acetals and acylsilane silyl enol ethers gives the corresponding α-silylalcohols in high yields with excellent diastereoselectivity. The protiodesilylation of α-silylalcohols proceeds with complete retention of the configuration. In addition, the reduction of acylsilanes having stereogenic centers at the α and β positions affords the corresponding α-silylalcohols in good yields with high diastereoselectivity similarly to the nucleophilic addition. And the treatment of acylsilanes having a phenyl group on silicon atom with fluoride ion results in the formation of phenyl carbinol derivatives via migration of the phenyl group with high diastereoselectivity.     

Two-dimensional supercritical behavior of an ethanol monolayer: a molecular dynamics study

The two-dimensional (2D) supercritical behavior of an ethanol monolayer formed at the vapor/liquid interface of an ethanol solution has been investigated by a molecular dynamics (MD) calculations with a combination of the OPLS-UA and SPC/E potential models. A 100 A thick slab of ethanol solution was placed at the volume center of the rectangular unit cell by 10 A thick nonabsorbate water surfaces. With such an initial configuration, five independent 15 ns NVT constant MD calculations were carried out under 298.15 K, in which the initial ethanol mole fraction of the bulk solution layer was set to 0.010, 0.022, 0.045, 0.10, and 0.20, respectively. The 2D radial distribution function (rdf) of an adsorbed ethanol molecule showed that the ethanol monolayer could be regarded as a 2D fluid where the adsorbed ethanol molecule had an effective 2D diameter of 4.65 A. On the basis of the 2D rdf result, 2D cluster analysis was carried out from the perspective of the percolation theory. It is confirmed that the critical area occupation probability density, the critical exponents, and the fractal dimension of both nonpercolating and percolating clusters satisfied their nature of universality. Therefore, we concluded that an ethanol monolayer formed at the vapor/liquid interface of ethanol solution behaves as a 2D supercritical fluid at 298.15 K.