Reprocessing of spent nuclear fuel (SNF) is an important task in a frame of ecology and rational use of natural resources. Uranium, as the main component of SNF (>95%), can be recovered for further ...use as fresh nuclear fuel. To minimize an amount of solid radioactive waste generated during SNF reprocessing, new extractants are under investigation. Diamides of 1,10-phenanthroline-2,9-dicarboxylic acid are perspective tetradentate N-donor ligands that form strong complexes with f-elements, which are soluble in polar organic solvents. As an example of three ligands of this class, we conducted a comparative study and showed how the substituent in the amide functional group affects the extraction ability toward uranyl nitrate from nitric acid media. We have performed a careful study (NMR, FT-IR, XRD, RMC-EXAFS) of the structures of synthesized complexes of new ligands with uranyl nitrate and used quantum mechanical calculations to explain the discovered regularities through.
The structures of sulfur-containing 8–10-membered cyclic alkynes capable of undergoing the strain-promoted azide-alkyne cycloaddition reaction have been computationally simulated. The conformational ...behavior for a series of sulfur-containing cycloalkynes was evaluated using the methods of quantum chemistry, as well as the ring strain for such compounds was estimated.
Fused 2-amino-3-cyano-4
H
-pyrans were synthesized by the tandem Knoevenagel—Michael reaction. A previously unknown version of the ring opening of 2-amino-3-cyano-4
H
-pyrans giving substituted ...2,6-dicyanoaniline was discovered. The structure of the latter compound was established by X-ray diffraction.
New nicotinamide derivatives have been synthesized by reactions of enamino ketones, aryl(hetaryl)methylidenecyanothioacetamides, alkylating agents, formamide, and cycloalkanones. The structure of ...some of the synthesized compounds has been determined by X-ray analysis.
Nicotinamide and nicotinonitrile derivatives containing a C
5
–C
7
-cycloalkane ring fused to the C
4
–C
5
bond were synthesized via Knoevenagel condensation, nucleophilic vinylic substitution (S
N
...Vin), and alkylation. The structure of (1-amino-5-phenyl-5,6,7,8-tetrahydrothieno2,3-
c
isoquinolin-2-yl)(phenyl)methanone was determined by X-ray analysis.
Multicomponent condensation of alkylating reagents with carbonyl compounds functionalized by CH-acids is initiated by the Knoevenagel reaction and leads to the formation of substituted pyridines, ...thienopyridines, pyridothienopyridines, and pyrimidothienopyridopyrimidines. The structure of the key products was studied by the X-ray diffraction method.
The tandem Knoevenagel—Michael—intramolecular ammonolysis—alkylation reaction was used to synthesize functionalized tetrahydropyridones. The molecular and crystal structures of four pyridone ...derivatives were studied by X-ray diffraction.
New cycloalka
b
pyridine and chromene derivatives were synthesized by multicomponent condensations. The structure of some of the synthesized compounds was determined by X-ray analysis.
2-Amino-3-cyano-4
H
-pyran and -thiopyran derivatives were synthesized by three-component reactions of aldehydes, dimedone, and CH acids. The molecular and crystal structures of the synthesized ...compounds were determined by X-ray analysis.
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