Spectroelectrochemical Properties and Catalytic Activity in Cyclohexane Oxidation of the Hybrid Zr/Hf-Phthalocyaninate-Capped Nickel(II) and Iron(II) tris-Pyridineoximates and Their Precursors

The in situ spectroelectrochemical cyclic voltammetric studies of the antimony-monocapped nickel(II) and iron(II) tris-pyridineoximates with a labile triethylantimony cross-linking group and Zr(IV)/Hf(IV) phthalocyaninate complexes were performed in order to understand the nature of the redox events in the molecules of heterodinuclear zirconium(IV) and hafnium(IV) phthalocyaninate-capped derivatives. Electronic structures of their 1e-oxidized and 1e-electron-reduced forms were experimentally studied by electron paramagnetic resonance (EPR) spectroscopy and UV−vis−near-IR spectroelectrochemical experiments and supported by density functional theory (DFT) calculations. The investigated hybrid molecular systems that combine a transition metal (pseudo)clathrochelate and a Zr/Hf-phthalocyaninate moiety exhibit quite rich redox activity both in the cathodic and in the anodic region. These binuclear compounds and their precursors were tested as potential catalysts in oxidation reactions of cyclohexane and the results are discussed.     

Preliminary results of the experiment on search for neutron nuclei on a nuclear reactor

An experiment on search for neutron nuclei in the reaction of neutron-induced fission of ²³⁵U nuclei has been performed on a nuclear reactor. The hypothetical reaction ¹²²Te(^xn, (x ? k)n)^{122 + k} Te → (β^?) → ^{122 + k} I (x = k ≥ 10) has been investigated. The radiochemical method for selecting iodine isotopes from tellurium was used. The upper limit on the probability of formation of neutron clusters has been obtained: P _k ≤ 10^?8 (fission)^?1 for ¹¹n clusters and P _k ≤ 10^?9 (fission)^?1 for ¹¹n clusters.     

Toward a prostate specific antigen-based prostate cancer diagnostic assay: preparation of keyhole limpet hemocyanin-conjugated normal and transformed prostate specific antigen fragments

Prostate specific antigen (PSA) molecules secreted by cancerous and normal prostate cells differ in their N-linked glycan composition, while the peptide backbone appears to be conserved. Antibodies selectively recognizing such differentially glycosylated PSA structures could form a basis for a new diagnostic assay for prostate cancer. Twenty-amino acid PSA fragments carrying di-, tri-, and tetrabranched complex-type glycans were prepared by total synthesis and conjugated to maleimide-modified keyhole limpet hemocyanin (KLH) carrier protein through backbone Cys residues. These glycopeptide/KLH conjugates were then used for antibody generation.     

Why are the hydroxy groups of partially protected N-acetylglucosamine derivatives such poor glycosyl acceptors, and what can be done about it? A comparative study of the reactivity of N-acetyl-, N-phthalimido-, and 2-azido-2-deoxy-glucosamine derivatives in glycosylation. 2-Picolinyl ethers as reactivity-enhancing replacements for benzyl ethers.

Competition experiments were used to determine that the 4-OH of a 2-deoxy-2-azidoglucose derivative is more reactive than that of the corresponding N-phthalimido glucose derivative which, in turn, is more easily glycosylated than the N-acetyl derivative. Glycosylation of the 4-OH groups of the N,N-diacetyl and N-acetyl-N-benzyl glucosamine was also found to be superior to that of the simple N-acetyl substance. The 3-O-picolinyl ether of a 4,6-O-benzylidene-protected N-acetylglucosamine was shown to have a strong intramolecular hydrogen bond to the adjacent acetamide group. This interaction does not persist in the 3-O-picolinyl-6-O-benzyl N-acetylglucosamine derivative, owing to a probable competing hydrogen bond between the 4-OH and the picolinyl ether. However, in the 3-O-picolinyl-4-O-benzyl N-acetylglucosamine regioisomer the picolinyl-acetamide hydrogen bond persists and leads to an enhancement of reactivity of the 6-OH, over and above that in the corresponding 3-O-benzyl ether, due to disruption of the typical intermolecular amide hydrogen bonding scheme. It is demonstrated that the picolinyl ether is readily removed by hydrogenolysis at atmospheric pressure and room temperature.     

Nitrogen-Containing Organomineral Fertilizer Based on Wood Waste

A new nitrogen-containing fertilizer was obtained by oxidative ammonolyis from wood waste. The chemical composition of the fertilizer was studied by functional chemical analysis. The fertilizer was tested in field conditions.     

Influence of the Adhesion Force and Strain Hardening Coefficient of the Material on the Rate of Adhesive Wear in a Dry Tangential Frictional Contact

Russian Physics Journal - In the paper, we consider the tangential contact of single microasperities of the interacting surfaces the mechanical characteristics of which are close to the...     

Effect of the crystal structure of a deuterated target on the yield of neutrons in the dd reaction at ultralow energies

The energy dependence of the neutron yield in the d(d, n)₃ He reaction proceeding in a textured titanium deuteride target with the preferred orientation of microcrystals in the [100] direction has been studied. Measurements have been performed for the energy range of incident deuterons of 7–12 keV in the laboratory system. It has been shown that the energy dependence of the enhancement factor of the reaction is described not only by the screening potential but also by the simple inclusion of channeling effects.