Incorporation of cationic electron donor of Ni-pyridyltetrathiafulvalene with anionic electron acceptor of polyoxometalate

A new salt-[Ni(II)(DMSO)(5)(TTFPy)](2)[α-SiW(12)O(40)] (1)-based on polyoxometalates was prepared by coordinating a cationic electron donor of pyridyltetrathiafulvalene (TTFPy) with Ni(II). Although the TTFPy molecule did not form a salt with the anionic α-[SiW(VI)(12)O(40)](4-) because of the weak charge-transfer (CT) interaction, the coordination of Ni with the pyridyl moiety permitted salt formation driven by electrostatic interaction, giving a single crystal of 1. Crystallographic analysis, UV-vis and IR spectroscopy and electrochemical characterization revealed that the fully oxidized α-[SiW(VI)(12)O(40)](4-) was crystallized with the neutral TTFPy moiety from the acetonitrile solution because of the low electron-withdrawing ability of α-[SiW(VI)(12)O(40)](4-), forming a brown-orange crystal. The crystal colour quickly turned to black by immersing in methanol, due to CT from TTF moiety to α-[SiW(VI)(12)O(40)](4-), which was caused by the solvent effect. Increase in the solvent acceptor number from 18.9 for acetonitrile to 41.3 for methanol resulted in the enhancement of the electron withdrawing ability of α-[SiW(VI)(12)O(40)](4-) by 0.317 V in methanol.     

A systematic study on matrix models for Chern–Simons-matter theories

We investigate the planar solution of matrix models derived from various Chern–Simons-matter theories compatible with the planar limit. The saddle-point equations for most of such theories can be solved in a systematic way. A relation to Fuchsian systems play an important role in obtaining the planar resolvents. For those theories, the eigenvalue distribution is found to be confined in a bounded region even when the ?t Hooft couplings become large. As a result, the vevs of Wilson loops are bounded in the large ?t Hooft coupling limit. This implies that many of Chern–Simons-matter theories have quite different properties from ABJM theory. If the gauge group is of the form U_(N1)k1×U_(N2)k2$\mathrm{U}{(N_1)}_{k_1}\times \mathrm{U}{(N_2)}_{k_2}$, then the resolvents can be obtained in a more explicit form than in the general cases.     

A new approach to Bezout equations derived from multivariate polynomial matrices and real entire functions

This paper focuses on Bezout equations derived from multivariate polynomial matrices in which relationships between one primary variable and other variables are described by real entire functions. We propose a method for obtaining a solution belonging to a set of multivariate rational function matrices in which all entries are real entire functions with respect to the primary variable. The proposed method is based on a new approach that overcomes the constraints and difficulties due to many variables by expanding a class of solutions to multivariate rational function matrices.     

X‐ray fluorescence analysis of Cr,As, Se,Cd, Hg,and Pb in soil using pressed powder pellet and loose powder methods

Quantitative analyses of Cr, As, Se, Cd, Hg, and Pb in soil were performed using wavelength dispersive X‐ray fluorescence (WDXRF) spectrometry with pressed powder pellet and loose powder methods. Standard soil samples containing hazardous metals were prepared by adding appropriate amounts of aqueous standards to base soils and then drying and homogenizing them. Base soil powders ground to less than 12.5 µm of modal particle size were Tachikawa loam, brown forest soil, and weathered granite containing 17.9, 9.43, and 3.49 mass% of Fe₂O₃, respectively. Analytical lines were CrKα, AsKα, SeKα, CdKα, HgLα, and PbLβ, with accompanying corrections for overlapping of SeKβ to PbLβ and PbLα to AsKα. Specimens for XRF analysis were prepared using powder pellets pressed to 23 mm internal diameter of an Al ring with 300 kgf cm^?2, and loose powder in a 31 mm internal diameter polyethylene cup covered with 6‐µm thickness of polypropylene film. Calibration curves drawn using the proposed standards showed good linearity under 3000 mg kg^?1 for the five metals, and 300 mg kg^?1 for Hg. Corrections with Compton scattering for AsKα, SeKα, CdKα, HgLα, and PbLβ, and with background scattering for CrKα were effective and produced identical inclinations of calibration curves. CdKα having larger critical depth in the loose powder specimen showed merely smaller inclination of calibration curve than that of the pressed powder specimen because of optical shading. The spike test for five analytes showed good recovery for gravel soil and pumice soil. Copyright © 2009 John Wiley & Sons, Ltd.     

Vacuum ultraviolet luminescence from a micro-pulling-down method grown Nd:(La0.9,Ba0.1)F2.9

Vacuum ultraviolet (VUV) luminescence from a Nd³⁺:(La_1−x,Ba_x)F_3−x (x=0.1) and a Nd³⁺:LaF₃ single crystal grown by the micro-pulling-down method modified for fluoride crystal growth is discussed. Emission resulting from excitation with 157 nm pulses of a F₂ laser and by 290 nm femtosecond pulses of a Ti:sapphire laser show that the luminescence spectral and temporal characteristics are similar for both excitation cases and that they have good prospects as a VUV laser material.     

Preparation of polymers containing the 1,3,4-oxadiazoline-5-thione structure and their application to the activation of N-protected α-amino acids

Two new monomers with pendent 1,3,4-oxadiazoline-5-thione structures were prepared. Homopolymerization of 2-isopropenyl-1,3,4-oxadiazoline-5-thione (V) and copolymerization with styrene (M₁)(r₁ = 0.02, r₂ = 1.56, Q = 4.12, e = 1.06) were examined. Further, 2-(4-methacryloylaminophenyl)-1,3,4-oxadiazoline-5-thione (VIII) having a phenylcarbamoyl group between the isopropenyl and 1,3,4-oxadiazoline-5-thione ring as a spacer was also synthesized and polymerized. The resultant polymers were allowed to react with N-protected α-amino acids such as Z-AlaOH, Z-LeuOH and Z-PheOH by the DCC method. The polymers containing amino acids thus obtained were reacted with ethyl glycinate to give the corresponding dipeptides in excellent yields without racemization.     

Silica gel high-performance liquid chromatography for the determination of cross-links in elastin

A high-performance liquid chromatographic (HPLC) procedure for the determination and preparation of desmosine (DES) and isodesmosine (IDE), the major cross-links of elastin, has been developed. Hydrolysates of elastin are treated with a SEP-PAK silica-gel small column and then separated on a silica-gel normal phase column using n-propanol-water-25% ammonia (9:3:0.06, v/v/v) followed by detection at 275 nm. The quantitative yields of DES and IDE are 7.98 +/- 0.47 and 6.44 +/- 0.51 (mean +/- S.D., n = 10) mg/g dry weight, respectively, in bovine ligamentum nuchae. Preparations of cross-links are carried out by means of a preparative column (240 mm x 10 mm), using the same solvent system.     

A simple method for the visualization of the separated zones of sugars on silica-gel TLC plates without spray reagent

A simple procedure of visualization of the separated zones of sugars on silica gel TLC plates without spray reagent is described. The plate is placed into a glass chamber filled with n-hexane. The separated sugars are then seen as opaque zones.