Fe(III), Co(II,III), and Ni(II) phenanthrolinate peroxodisulfates

Complexes with the compositions [Fe(Phen)₃]₂(S₂O₈)₃ · 2H₂O, [Co(Phen)₃]₂(S₂O₈)₃ · 8H₂O, Co(Phen)₂S₂O₈ · 3H₂O, and [Ni(Phen)₂(H₂O)₂]S₂O₈ were synthesized and studied by spectroscopic, X-ray powder diffraction, and TG methods.     

Solvent-free and transition metal catalyst-free synthesis of indolo[1,2-f]phenanthridine from 6-chlorophenanthridine

A new easily scalable synthesis of the important for materials chemistry indolo[1,2-f]phenanthridine from commercially available 6-chlorophenanthridine was developed. The suggested transition metal catalyst-free and solvent-free procedure is more ecologically friendly and cost efficient then the known methods. The yields of indolo[1,2-f]phenanthridine synthesized from 6-chlorophenanthridine in three steps were 20% and 26% if the cyclization was carried out solvent-free and in THF in the presence of lithium 2,2,6,6-tetramethylpiperidide, respectively.

     

New phosphorylated glycoluril derivatives

The N-acylation of glycoluril with 1-haloacetyl halides was studied. The optimal conditions and reaction regioselectivity, as well as the effect of reagent molar ratios, base nature, temperature, and reaction time on the yield of the target product were established. It was shown that the chemical modification of the synthesized bis(bromoacetyl) derivative of glycoluril by phosphorylation by the classical Arbuzov reaction gave a previously unknown bis(diethylphosphonoacetyl) derivative of glycoluril. The consecutive silylation and hydrolysis of the latter derivative gave the corresponding bis(phosphonoacetyl) derivative which presents interest as a potentially biologically active compound.     

A quantum chemical approach to the mechanism of the biochemical action of nicotinamide

The reaction of protonated nicotinamide with hydride ion, which models the transfer of hydrogen from a substrate to the nicotinamideadeninedinucleotide (NAD⁺) molecule, i.e., the principal biological function of vitamin PP, was investigated by optimization of the geometry in terms of the self-consistent field (SCF) method with allowance for configuration interaction (CI) in the PM-3 approximation. It was shown that the initial event of the reaction is electron transfer, followed by the addition of a hydrogen atom to the NAD radical. The addition product is relatively stable and has a heat of formation of −68.25 kJ/mol. The geometric structure and the distribution of charges of the reagent and also the behavior of the singlet and triplet terms in the course of the reaction were analyzed. Translated from Teoreticheskaya i éksperimental'naya Khimiya, Vol. 35, No. 5, pp. 277–283, September–October, 1999.     

General Method of Synthesis of 5-(Het)arylamino-1,2,3-triazoles via Buchwald–Hartwig Reaction of 5-Amino- or 5-Halo-1,2,3-triazoles

An efficient access to the novel 5-(het)arylamino-1,2,3-triazole derivatives has been developed. The method is based on Buchwald–Hartwig cross-coupling reaction of 5-Amino or 5-Halo-1,2,3-triazoles with (het)aryl halides and amines, respectively. As result, it was found that palladium complex [(THP-Dipp)Pd(cinn)Cl] bearing expanded-ring N-heterocyclic carbene ligand is the most active catalyst for the process to afford the target molecules in high yields.     

Supercritical fluid encapsulation of acizol into aliphatic polyether microparticles

Encapsulation of pharmaceutical grade acizol (Acizol® pharmaceutical substance) into bioresorbable D,L-polylactide and polylactoglycolide microparticles using supercritical carbon dioxide has been studied. An effective way for formation of polymer fine powders (mean particle size of about 10–20 µm) containing up to 20 wt % of the bioactive component without any organic solvent used has been suggested. Raman spectroscopy with spatial resolution was employed to analyze the distribution of acizol throughout the volume of the individual polymer microparticles and to study the kinetics of its release into saline. The rapid release (40–80% of the total amount of the encapsulated substance) from the samples under study was observed during the first hour, and then it was followed by a gradual, almost linear release between the 4th and 14th days of the experiment, with the total release continuing up to 100%.     

Effect of glycoluril and its derivatives on the flame resistance and physico-mechanical properties of rubber

The effect of bicyclic bisureas (glycolurils) and their derivatives functionalized with hydroxymethyl, halomethyl, and dimethoxyphoshorylmethyl groups on the flame resistance and physico-chemical properties of synthetic isoprene and divinyl rubbers was studied, and the procedures for preparing these agents were suggested. The rubbers with the addition of the synthesized bicyclic bisureas demonstrated satisfactory levels of flame resistance and physico-mechanical parameters.     

Solvent-free palladium-catalyzed C–O cross-coupling of aryl bromides with phenols

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Physical Methods for Determining the Phase Composition of Gallstones

Crystallography Reports - Gallstones with a zonal morphological structure have been studied using X-ray microtomography, X-ray diffraction analysis, Raman spectroscopy, and elemental analysis....     

Synthesis and luminescent properties of copper(I) complexes with 3-pyridin-2-yl-5-(4-R-phenyl)-1<Emphasis Type="Italic">H</Emphasis>-1,2,4-triazoles

A series of heteroligand copper(I) complexes with 3-pyridin-2-yl-5-(4-R-phenyl)-1H-1,2,4-triazoles (R = H, CH₃, CH₃O) and PPh₃ of general composition CuIL(PPh₃) have been synthesized and studied. The compounds have been characterized by elemental analysis, IR spectroscopy, and diffusion reflectance spectra. The structure of the complex with 3-pyridin-2-yl-5-phenyl-1H-1,2,4-triazole has been determined by single-crystal X-ray diffraction analysis. The complex is mononuclear and has a tetrahedral environment of the central atom. The compounds exhibit strong visible photoluminescence (λ_max = 599–609 nm). Quantum-chemical calculations at the B3LYP/DGDZVP level have demonstrated that the short phosphorescence life-time of the CuIL(PPh₃) compounds is caused by intensity transfer from the S ₀–S ₂ transition through spinorbit coupling induced by the rotation of the iodine 5p orbital upon the T ₁–S ₂ transition.