Stereoelectronic effects on cyclobutyl participation. The 10-tetracyclo[5.2.1.02,6.O3,9]decyl cation

While the solvolysis of tosylate 5c proceeds very rapidly to generate 4 or its rapidly equilibrating classical alternative, the epimeric compound 6c proved to be unreactive; bond orientation effects are implicated.     

The direct inverse method: A novel approach to estimate adsorption isotherm parameters

A novel method to estimate adsorption isotherm parameters is presented and its applicability is studied through synthetic as well as experimental data. This approach assumes a linear dependency of the UV absorption intensity on the solute concentration in the fluid phase, at least in certain ranges of the UV spectra. It was demonstrated that by fitting the absorption profiles, i.e. the new direct inverse method, and by fitting the concentration profiles, i.e. the classical inverse method, very similar adsorption isotherm parameters can be obtained. The findings presented in this work have as important implication the elimination of the requirement of converting a measured absorption intensity into a concentration value, i.e. the elimination of the calibration of the UV signal.     

Fourier analysis based phase shift interferometric tomography for three-dimensional reconstruction of concentration field around a growing crystal

The present work is concerned with the three-dimensional reconstruction of concentration field around a crystal growing from its aqueous solution using Fourier analysis based phase shift interferometric tomography. Projection data of convective field around a growing NaClO₃ crystal have been recorded using a Mach–Zehnder interferometer. A new numerical method based on the concept of real time phase shift interferometry has been employed for the analysis of the interferograms. By interpreting the interferograms as projection data, the 3-D distribution of salt concentration has been determined using principles of tomography. Study shows that the Fourier analysis-based phase shift method is a novel approach for crystal growth studies as it requires only one interferometric image for the determination of full phase information as opposed to the conventional real time phase shift interferometry wherein at least three or more phase-shifted interferograms are needed. Results have been presented in the form of interferograms, path-integrated concentration contours and three-dimensional concentration profiles over select horizontal planes above the growing crystal. Based on the reconstruction results, distribution of salt concentration in the crystal vicinity is determined and an appropriate mechanism of buoyancy-induced fluid movement in the growth chamber is discussed.     

Nanoscale three‐dimensional optical visualization method for a deformation of elastomer printing plate to realize soft nano‐printing technology

Printed electronics, in which microcircuit patterns are fabricated using printing methods, are the focus of considerable attention for the fabrication of devices such as flat panel displays, solar cells, and flexible electronics. In particular, gravure offset printing is considered to be a highly promising approach for rapid printing of fine patterns with well‐controlled thickness. At present, however, because of the occurrence of side etching during fabrication of metal printing plates, features with dimensions of less than 10 µm cannot be printed. In order to overcome this problem, we have previously proposed the use of a rubber printing plate fabricated by photolithography and molding, which is free from side‐etching issues. However, deformation of the printing plate can have a detrimental influence on the transferred pattern. In the present study, we developed a method for visualizing the deformation of a printing plate containing both micropatterns and nanopatterns, in order to study its effect on the printing process. The results were compared with those predicted by an analytic equation under a uniform controlled pressure. Copyright © 2015 John Wiley & Sons, Ltd.     

Diverse structures and adsorption properties of quasi-Werner-type copper(II) complexes with flexible and polar axial bonds

The quasi-Werner-type copper(II) complex, [Cu(PF(6))(2)(4-mepy)(4)] (1), in which 4-mepy is the 4-methylpyridine ligand, has flexible and polar axial bonds of Cu-PF(6). Flexibility of the Cu-PF(6) bonds induces diverse and unprecedented guest-inclusion structures, such as {[Cu(PF(6))(2)(4-mepy)(4)][Cu(PF(6))(4-mepy)(4)(acetone)]·PF(6)·4acetone} (γ-1?2.5acetone), {[Cu(PF(6))(2)(4-mepy)(4)][Cu(PF(6))(4-mepy)(4)(2-butanone)]·PF(6)·3.5(2-butanone)} (γ-1?2.25(2-butanone)), {[Cu(PF(6))(2)(4-mepy)(4)][Cu(PF(6))(4-mepy)(4)(H(2)O)]·PF(6)·4benzene} (γ-1?0.5H(2)O·2benzene), and {[Cu(PF(6))(2)(4-mepy)(4)]·2benzene} (γ-1?2benzene). Exposure of the dense form, α-1, to benzene vapor affords the benzene-inclusion complex {[Cu(PF(6))(2)(4-mepy)(4)]·2benzene} (γ-1?2benzene), all benzene guests of which are easily removed by vacuum drying, reforming guest-free, dense α-1' with smaller sized crystals than α-1. In contrast to α-1, which shows almost no CO(2) adsorption, α-1' adsorbs CO(2) gas with structural transformations, this being the first example that exhibits adsorption of gas in a dense Werner-type complex and a drastic change in adsorption properties depending on the size of the crystals.     

Alkylation and H-D Exchange of Tetraazathiapentalenes Fused with Pyrimidine and/or Pyridine Ring

Selectivity of alkylation of and that of deuteration of methyl groups attached to the pyrimidine ring of tetraazathiapentalenes are discussed.     

RING-TRANSFORMATION FROM ISOTHIAZOLE TO 1,2,4-THIADIAZOLE - POSSIBLE INTERMEDIACY OF π-SULFURANE

Abstract

5-Amino-3-methyl- and 5-amino-3-phenylisothiazoles (3a and 3b) afforded 1 : 1 adducts with aromatic nitriles and imidates. On the basis of their spectral data and the structure of hydrolysis products, the adducts were identified as 3-substituted 5-(2-aminovinyl)-1,2,4-thiadiazole derivatives (2a-g), where ring transformation took place from isothiazole to 1,2,4-thiadiazole.     

A novel synthesis of 2-(disubstituted amino)-5(4)phenylimidazoles

The reaction of 1-phenyl-1,2-propanedione with 1,1-disubstituted guanidines in methanol yielded 2-(disubstituted amino)-4-hydroxy-4-methyl-4H-imidazoles (III). Compound III produced 5(4)methylimidazoles by catalytic hydrogenation and 5(4)chloromethylimidazoles (IV) by concentrated hydrochloric acid treatment. Solvolysis of IV in water and alcohols gave 5(4)hydroxymethyl- and 5(4)alkoxymethylimidazoles, respectively.     

Extra-column dead volume in simulated moving bed separations: Theory and experiments

In small-scale SMB units typically set up by a number of HPLC columns connected in series, the volume of the connecting tubing parts and valves may become comparable to the column volume. Therefore, to guarantee proper and satisfying separation results, the introduced extra-column dead volume needs to be considered in the calculations of the operating parameters. In this work, the impact of extra-column dead volume on the separation performance is studied, with the objective to introduce guidelines and rather simple rules to account for it. It is shown, how these results can be used in the frame of the triangle theory to determine operating conditions that allow to achieve the desired separation performance. For the experiments the separation of a racemic mixture of (±$\pm$)-3,5-bis[1-(4-methoxyphenyl)-1-methyl]hepta-3,4-diene-1,6-diyne was carried out. The numerical model used for the simulation describes explicitly the geometric configuration of the HPLC–SMB laboratory unit to take into account the effect of extra-column dead volume.