RESUMEN
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.
RESUMEN
Novel continuous-flow cascade reactions are developed for producing 1,4-diaryl-disubstituted dipolar γ-carbolines 2 that contain a carboxylate group and their two pentacyclic precursors 6, 7 from hemiindigos 1. The nucleophilic and pro-electrophilic chemistry described is new to the hemiindigos 1, and it led to the discovery of antimycobacterial scaffold characteristic of rimino-type pentacycles 6, 7 and potent drug clofazimine. The new scaffold like clofazimine appears to be useful in developing lead agents active against drug-resistant/dormant TB.
RESUMEN
Novel unsymmetrical ligands, 1-thiophosphoryloxy-3-thiophosphorylbenzenes 3a-d, bearing phosphine sulfide and thiophosphoryloxy moieties as coordinating sites, were found to undergo cyclometalation at the C-2 position of the central benzene ring in a reaction with bis(benzonitrile)palladium dichloride affording rare examples of nonsymmetrical pincer complexes, namely [2-{(thiophosphoryl)oxy}-6-(diphenylthiophosphoryl)phenyl]palladium chlorides 4a-d, containing 5- and 6-membered fused metallacycles with kappa3-SCS'-coordination. Molecular structures of the complexes were characterized by X-ray diffraction. These complexes demonstrated high catalytic activity for the Suzuki cross-coupling reactions of aryl bromides with phenylboronic acid.