No abstract

Some unexpected “structure–extraction properties” patterns were found for new family of 1,10-phenanthroline-2,9-diamide derived ligands.

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 three-dimensional solid-state structures of two modifications of doxazosin mesylate (C23H26N5O5)+.(CH3SO3)-, 4-amino-2-[4-[(2,3-dihydro-1,4-benzodioxin-2-yl)carbonyl]piperazin-1-yl]-6,7-dimethoxyquinazoline methanesulfonate, a commonly used antihypertensive agent, have been determined by synchrotron X-ray powder diffraction. An anhydrous form (A) and a dihydrate form (dG) crystallize in monoclinic space groups. In both forms the doxazosin molecule is protonated at the N1 atom of the quinazoline bicycle. The N1 atom, and the amino H atoms and O atoms of the mesylate moieties are involved in three-dimensional hydrogen-bonding networks, while solvent water molecules and carboxamide O atoms are also incorporated in a hydrogen-bonding network in dG.