Crystal structure of 4,4″-dinitro-[3,3′,4′,3″]-tris-[1,2,5]-oxadiazole

The crystal structure of a new energetic compound of 4,4″-dinitro-[3,3′:4,3″]-tris-[1,2,5]-oxadiazole is studied.     

Complexation of Am(III) and Nd(III) by 1,10-Phenanthroline-2,9-Dicarboxylic Acid

The complexant 1,10-phenanthroline-2,9-dicarboxylic acid (PDA) is a planar tetradentate ligand that is more preorganized for metal complexation than its unconstrained analogue ethylendiiminodiacetic acid (EDDA). Furthermore, the backbone nitrogen atoms of PDA are aromatic, hence are softer than the aliphatic amines of EDDA. It has been hypothesized that PDA will selectively bond to trivalent actinides over lanthanides. In this report, the results of spectrophotometric studies of the complexation of Nd(III) and Am(III) by PDA are reported. Because the complexes are moderately stable, it was necessary to conduct these titrations using competitive equilibrium methods, competitive cation complexing between PDA and diethylenetriaminepentaacetic acid, and competition between ligand protonation and complex formation. Stability constants and ligand protonation constants were determined at 0.1 mol·L^?1 ionic strength and at 0.5 mol·L^?1 ionic strength nitrate media at 21 ± 1 °C. The stability constants are lower than those predicted from first principles and speciation calculations indicate that Am³⁺ selectivity over Nd³⁺ is less than that exhibited by 1,10-phenanthroline.     

Determination of Indicator Congeners of Polychlorinated Biphenyls in Water at Ultratrace Levels by Gas Chromatography–Tandem Mass Spectrometry

Journal of Analytical Chemistry - We validated a procedure for the determination of indicator congeners (ICs) of polychlorinated biphenyls (PCBs) (IUPAC nos. 28, 52, 101, 118, 138, 153, and 180) in...     

Fabrication of composite based on GeSi with Ag nanoparticles using ion implantation

Comparative analysis of the structural and optical properties of composite layers fabricated with the aid of implantation of single-crystalline silicon (c-Si) using Ge⁺ (40 keV/1 × 10¹⁷ ions/cm²) and Ag⁺ (30 keV/1.5 × 10¹⁷ ions/cm²) ions and sequential irradiation using Ge⁺ and Ag⁺ ions is presented. The implantation of the Ge⁺ ions leads to the formation of Ge: Si fine-grain amorphous surface layer with a thickness of 60 nm and a grain size of 20–40 nm. The implantation of c-Si using Ag⁺ ions results in the formation of submicron porous amorphous a-Si structure with a thickness of about 50 nm containing ion-synthesized Ag nanoparticles. The penetration of the Ag⁺ ions in the Ge: Si layer stimulates the formation of pores with Ag nanoparticles with more uniform size distribution. The reflection spectra of the implanted Ag: Si and Ag: GeSi layers exhibit a sharp decrease in the intensity in the UV (220–420 nm) spectral interval relative to the intensity of c-Si by more than 50% owing to the amorphization and structuring of surface. The formation of Ag nanoparticles in the implanted layers gives rise to a selective band of the plasmon resonance at a wavelength of about 820 nm in the optical spectra. Technological methods for fabrication of a composite based on GeSi with Ag nanoparticles are demonstrated in practice.     

Antiferromagnetic interactions in single crystalline Zn1-xCoxO thin films

In a rather contradictory situation regarding magnetic data on Co-doped ZnO, we have succeeded in fabricating high-quality single crystalline Zn(1-x)Co(x)O (x=0.003-0.07) thin films. This gives us the possibility, for the first time, to examine the intrinsic magnetic properties of ZnO:Co at a quantitative level and therefore to address several unsolved problems, the major one being the nature of the Co-Co interaction in the ZnO structure.     

3-Cyanoazolo[5,1-c][1,2,4]triazines: synthesis and antiviral activity

Chemistry of Heterocyclic Compounds - A series of azolo[5,1-c][1,2,4]triazines containing a cyano group were prepared as analogs of the drug Triazavirin (riamilovir). Sodium...     

Magnetoactive elastomer based on magnetically hard filler: Synthesis and study of viscoelastic and damping properties

This work is focused on the magnetic response of magnetoactive elastomer (MAE) based on silicone polymer matrices filled with magnetic particles of magnetically hard NdFeB-alloy. Viscoelastic properties of MAE were studied by the method of oscillation shear. After magnetization in an external magnetic field of 2 T MAE samples demonstrate more than two-time increase in the storage and loss moduli and 25% increase in the loss factor. Performed study of the damping properties of the materials has shown that the oscillation time of the pendulum hammering the magnetized sample is in two times shorter than in case of the non-magnetized sample. Viscoelastic and damping properties of MAE are defined by magnetic interactions between the magnetized particles of the magnetic filler.     

Kinetics and Mechanism of Thermal Decomposition of 1-(Dinitromethyl)-3-R-1H-1,2,4-triazoles

Russian Journal of General Chemistry - Kinetic regularities and the mechanism of thermal decomposition of 3-substituted 1-(dinitromethyl)1H-1,2,4-triazoles in the solid phase and in dibutyl...     

Underground Physics and the Nonlinear Delayed Barometric Effect of the Gamma-Ray Background

Journal of Experimental and Theoretical Physics - The electronic, magnetic, and optical properties of MnGa2O4 in the structure of the normal and inverse spinels are subjected to an ab initio...