Six-Nuclear Complexes of Platinum(II) and Palladium(II) with Mercamine and β-Mercaptoethanol

The platinum(II) and palladium(II) complexes [Pt₆(SCH₂CH₂NH₂)₈]Cl₄ and [Pd₆(SCH₂CH₂OH)₈ Cl₄· 5H₂O with mercamine and β-mercaptoethanol, respectively, were synthesized. It was found on the basis of the comparison of IR and X-ray electron spectra of the ligands and complexes, and also of the data of X-ray diffraction analysis that the bidentate coordination of ligands through sulfur and nitrogen atoms is realized in the platinum(II) complex. In the palladium(II) complex β-mercaptoethanol is coordinated in a mixed-mode type. In both complexes sulfur atoms of the ligands occupy a bridging position.     

Methanol Electro-Oxidation in Alkaline Medium by Ni Based Binary and Ternary Catalysts: Effect of Iron (Fe) on the Catalyst Performance

Russian Journal of Electrochemistry - Pt free methanol electro oxidation catalysts with stable response are of interest to reduce the overall cost of the direct methanol fuel cell (DMFC). Here,...     

Vibrational analysis,conformational stability,force constants,internal rotation barriers,MP2=full and DFT calculations of 1,3-dimethyluracil tautomers

The molecular structure of 1,3-dimethyluracil (C₆H₈N₂O₂; 1,3-DMU) is studied theoretically and experimentally using Gaussian 98 calculations and different spectroscopic techniques. The vibrational spectrum for 1,3-DMU in the solid phase is recorded in the IR range 4000-400 cm^–1. Initially, in order to get the most stable structure, twelve structures were proposed for the titled compound as a result of the internal rotation of CH₃ around C–N bonds and keto-enol tautomerism. The single point energy and frequency calculations are obtained by MP2 (Full) and DFT/B3LYP methods with the 6-31G(d) basis set using the Gaussian 98 computation package. After the complete relaxation of twelve isolated isomers, the (diketo) tautomer was the only favored structure owing to its low energy relative to the other isomers and the prediction of real frequencies. This interpretation is supported by the recorded infrared spectrum that shows the presence of only the diketo tautomer. Aided by the normal coordinate analysis and potential energy distributions, a confident vibrational assignment of the fundamental frequencies is calculated. The results are discussed herein and compared with similar molecules whenever possible.     

Nanostructured DNA Microarrays for Dual SERS and Electrochemical Read‐out

We present a strategy to fabricate nanostructured microarrays ready to perform a dual read‐out, namely electrochemical (EC) as well as surface‐enhanced Raman spectroscopy (SERS) based detection of DNA hydridization. A polystyrene nanobeads monolayer assembly, obtained by means of a Langmuir Blodgett type technique, followed by electrochemical Au deposition, was employed to construct homogeneous nanostructures in the form of inverse‐opal nanovoids on a 32‐electrode Au microarray chip. Characterization of the obtained nanostructured electrodes of the array by means of cyclic voltammetry demonstrated high reproducibility of the surface modification process. The performance of the obtained array platform was investigated by modifying the microarray electrodes with three different oligonucleotide capture probes using a previously developed potential‐assisted surface modification protocol. Two ferrocene‐labeled target DNA sequences and one target RNA sequence with a Texas red label were detected electrochemically and via SERS, respectively.     

Strategy for the synthesis of Di- and polymer tartratogermanates with single-charge cations. Crystal structures of K2[Ge2(OH)2(μ-Tart)2] · 4.5H2O and (NH4)2n [Ge2(μ-O)(μ-Tart)2] n · nMeCN · nH2O

Tartratogermanates of alkaline metals and ammonium are synthesized for the first time using different solvents (water, acetonitrile) and starting reagents (GeO₂ and GeCl₄): dimeric Kat₂[Ge₂(OH)₂(μ-Tart)₂] · 4.5H₂O (H₄Tart is D-tartaric acid, Kat = Na (I) and K (II)) and polymer (NH₄)_2n [Ge₂(μ-O)(μ-Tart)₂] _n · nCH₃CN · nH₂O (III). The complexes are characterized by elemental analysis, IR spectroscopy, and X-ray diffraction analysis. The structure of complex II contains binuclear isolated [Ge₂(OH)₂(μ-Tart)₂]₂-complexes. In complex III, the oxo ligands join the binuclear fragments into polymer chains.     

Structure and intramolecular mobility of N-(thio)phosphoryl(thio)amides: XVI. 1H, 13C and 31P NMR study of intramolecular dynamics of N,N′-bis(thio)phosphoryl(thio)urea containing an open-chain fragment in CD2Cl2 and CD3CN solutions

The structure and intramolecular transitions of N,N′-bis[N-disopropoxythiophosphorylaminothiocarbonyl]-1,7-diaminoheptane in CD₂Cl₂ and CD₃CN 3–10% solutions were studied by means of ¹H, ¹³C, and ³¹P NMR spectroscopy. Combined analysis of the NMR data confirmed a high lability of the molecules with the realization of two conformational forms of the macromolecule, the amide-amide proton exchange, and existence of various tautomeric forms.     

Worldwide measurements of radioxenon background near isotope production facilities, a nuclear power plant and at remote sites: the “EU/JA-II” Project

The Comprehensive Nuclear-Test-Ban Treaty (CTBT) specifies that radioxenon measurements should be performed at 40 or more stations worldwide within the International Monitoring System (IMS). Measuring radioxenon is one of the principle techniques to detect underground nuclear explosions. Specifically, presence and ratios of different radioxenon isotopes allows determining whether a detection event under consideration originated from a nuclear explosion or a civilian source. However, radioxenon monitoring on a global scale is a novel technology and the global civil background must be characterized sufficiently. This paper lays out a study, based on several unique measurement campaigns, of the worldwide concentrations and sources of verification relevant xenon isotopes. It complements the experience already gathered with radioxenon measurements within the CTBT IMS programme and focuses on locations in Belgium, Germany, Kuwait, Thailand and South Africa where very little information was available on ambient xenon levels or interesting sites offered opportunities to learn more about emissions from known sources. The findings corroborate the hypothesis that a few major radioxenon sources contribute in great part to the global radioxenon background. Additionally, the existence of independent sources of ^131mXe (the daughter of ¹³¹I) has been demonstrated, which has some potential to bias the isotopic signature of signals from nuclear explosions.     

Spectroscopic reflectometry as in‐operando method for thickness determination of anodic oxide films on titanium

The present work focuses on the development of an in‐operando technique based on the visible spectroscopic reflectometry (VSR) for simultaneous determination of the oxide film formation during anodizing. The establishment of the VSR as in‐operando technique requires an extensive validation by comparative in‐situ but non‐operando thickness measurements under aqueous conditions. The investigations were carried out on anodic oxide films on pure titanium. The authors demonstrate the VSR as a simple and robust method for measurement under electrolyte covering. Additionally, an empirical correction algorithm extends the limitation of the visible reflectometry in thin film thickness. Reliable film thickness values can be measured down to ≥5 nm. The in‐operando mode yields additional information about the film growth time resolved. Copyright © 2013 John Wiley & Sons, Ltd.     

Condensation of 4-amino-3-hydrazino-1,2,4-triazoline-5-thione with α- and β-dicarbonyl compounds

sym-Triazolo[3,4-b][1,2,4,5]tetraazepines were obtained by condensation of 4-amino-3-hydrazino-1,2,4-triazoline-5-thione with -dicarbonyl compounds, and 1-[4-amino-1,2,4-triazol-3-yl]-3,5-dialkylpyrazoles were obtained by condensation of the same thione with -dicarbonyl compounds.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 4, pp. 555–559, April, 1978.