Chelating Diazoarylcelluloses for Selective Chromogenic Reactions

Russian Journal of General Chemistry - A number of polydentate diazoarylcelluloses have been proposed in the form of reagent indicator, in which the functional diazo group is connected to the rest...     

Hyperfine Interactions in Copper Lattice Sites of Antiferromagnetic Compounds Representing the Analogues of Superconducting Copper Metal-Oxide Compounds

Physics of the Solid State - Emission 61Cu(61Ni) Mössbauer spectra of dielectric metal-oxide compounds of divalent copper with molecular formulas Ca1 – xSrxCuO2,...     

Metal-Glass-Ceramic Phases on the Surface of Porous TiNi-Based SHS-Material for Carriers of Cells

Russian Physics Journal - Using the methods of SEM, EDS, and optical microscopy, a large number of non-metallic inclusions are revealed on the pore surface of a TiNi-based SHS-alloy. According to...     

The Role of Lignocellulosic Composition and Residual Lipids in Empty Fruit Bunches on the Production of Humic Acids in Submerged Fermentations

The aim of this research was to study the production of humic acids (HA) by Trichoderma reesei from empty fruit bunches (EFBs) of palm oil processing, with a focus on the effects of lignocellulosic content and residual lipids. EFBs from two different soils and palm oil producers were previously characterized about their lignocellulosic composition. Submerged fermentations were inoculated with T. reesei spores and set up with or without residual lipids. The results showed that the soil and the processing for removal of the palm fresh fruits were crucial to EFB quality. Thus, EFBs were classified as type 1 (higher lignocellulosic and fatty acids composition similar to the palm oil and palm kernel oil) and type 2 (lower lignocellulosic content and fatty acids composition similar to palm oil). Despite the different profiles, the fungal growth was similar for both EFB types. HA production was associated with fungal growth, and it was higher without lipids for both EFBs. The highest HA productivity was obtained from type 1 EFB (approximately 90 mg L⁻¹ at 48 h). Therefore, the lignocellulosic composition and the nature of the residual lipids in EFBs play an important role in HA production by submerged fermentation.

     

Intramolecular cyclization of N‐hetarylphosphinimidic isocyanates in the synthesis of 1,7‐dihydro‐4H‐imidazo[4,5‐d][1,3,2]diazaphosphinin‐4‐one (2‐phosphapurine)

It has been found that N‐(4‐imidazolyl)phosphinimidic isocyanates obtained by the reaction of the corresponding chlorophosphine N‐hetarylimide with alkali metal cyanates can undergo intramolecular heterocyclization to yield previously unknown phosphapurine derivatives containing an endocyclic PN double bond. This radically novel approach to building the 2‐phosphapurine system shows promise for the synthesis of related phosphorus‐containing fused heterocycles. © 2010 Wiley Periodicals, Inc. Heteroatom Chem 21:453–455, 2010; View this article online at wileyonlinelibrary.com . DOI 10.1002/hc.20617     

4‐Phosphorylated 1,2‐disubstituted imidazoles

4‐Selenophosphoryl‐1,2‐disubstituted imidazoles have been obtained by thermal decomposition of methyl 5‐(diamidoselenophosphoryl)imidazolium chlorides. The position of selenophosphoryl group in the imidazole ring was proved by ¹H, ¹³C NMR spectroscopy, and X‐ray analysis. Previously unknown diamido‐ and dichloro(imidazol‐4‐yl)‐ phosphonites were synthesized, and differences in their reactivity compared to analogous 5‐phosphorylated imidazoles are shown. © 2010 Wiley Periodicals, Inc. Heteroatom Chem 21:103–118, 2010; Published online in Wiley InterScience ( www.interscience.wiley.com ). DOI 10.1002/hc.20584     

Project of the ultracold and cold neutron source at the WWR-M reactor with superfluid helium as a moderator

The WWR-M reactor of the Petersburg Nuclear Physics Institute provides a unique opportunity for creating conditions of low radiative heat release (～4 × 10^?3 W/g) at a sufficiently high neutron flux (～3 × 10¹² neutrons/(cm² s)). This opportunity can be implemented in the reactor thermal column, which represents a 1-m-diameter channel adjacent to the reactor core. This diameter of the channel allows the arrangement of the core gamma shielding made of bismuth (15 cm thick), a graphite premoderator (300 dm³) at a temperature of 20 K, and a converter with superfluid helium (35 dm³) at a temperature of 1.2 K. Calculations show that the heat release in the source (20 W) can be removed by pumping helium vapor, and the density of ultracold neutrons in an experimental trap will be ～10⁴ neutrons/cm³, which is higher than that of existing sources of ultracold neutrons by two to three orders of magnitude.     

The effect of pulsed laser radiation on polyelectrolyte capsule shells modified with fluorescent dyes

Polyelectrolyte capsules containing rhodamine 6G and fluorescein isothiocyanate in their shells are obtained by successive adsorption on spherical microscopic CaCO₃ particles followed by the dissolution of the latter. Suspensions of the capsules are irradiated with a laser operating at a wavelength corresponding to the absorption bands of the dyes, and it is shown that shell modification with the selected dyes promotes photosensitized disruption of these structures. The mechanism proposed for this disruption is realized via energy transfer from photoexcited dye molecules to the polymer matrix. Therewith, the dye-modified capsules are disrupted due to their nonuniform local heating.     

Atomistic and Ab initio modeling of CaAl<Subscript>2</Subscript>O<Subscript>4</Subscript> high-pressure polymorphs under Earth’s mantle conditions

Semi-empirical and ab initio theoretical investigation of crystal structure geometry, interatomic distances, phase densities and elastic properties for some CaAl₂O₄ phases under pressures up to 200 GPa was performed. Two independent simulation methods predicted the appearance of a still unknown super-dense CaAl₂O₄ modification. In this structure, the Al coordination polyhedron might be described as distorted one with seven vertices. Ca atoms were situated inside polyhedra with ten vertices and Ca–O distances from 1.96 to 2.49 Å. It became the densest modification under pressures of 170 GPa (density functional theory prediction) or 150 GPa (semi-empirical prediction). Both approaches indicated that this super-dense CaAl₂O₄ modification with a “stuffed α-PbO₂” type structure could be a probable candidate for mutual accumulation of Ca and Al in the lower mantle. The existence of this phase can be verified experimentally using high pressure techniques.     

Investigation of N‐ and C‐Phosphanylation of [1,2,4]Triazolo[4,3‐a]pyridines

Synthesis and deprotonation of N‐phosphanylated[1,2,4]triazolo[4,3‐a]pyridinium triflates were investigated. Phosphanylation by t‐Bu₂PCl proceeds at N1 of starting triazolo‐pyridines. According to density functional theory calculations, deprotonation of the formed salt gives abnormal carbenes, which decompose by opening of the triazole cycle. Treatment by chlorodiphenylphosphane leads to an equilibrium mixture of N1‐ and N2‐phosphanylated salts, which under addition of base yields normal carbene that rapidly rearranges to form C‐phosphanylated product. Mechanisms of the reactions are discussed.