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A reaction of acyl chlorides derived from 1,10-phenanthroline-2,9-dicarboxylic acids with piperazine allows the preparation of the corresponding 24-membered macrocycles in good yield. The structural and spectral properties of these new macrocyclic ligands were thoroughly investigated, revealing promising coordination properties towards f-elements (Am, Eu). It was shown that the prepared ligands can be used for selective extraction of Am(III) from alkaline–carbonate media in presence of Eu(III) with an SFAm/Eu up to 40. Their extraction efficiency is higher than calixarene-type extraction of the Am(III) and Eu(III) pair. Composition of macrocycle–metal complex with Eu(III) was investigated by luminescence and UV-vis spectroscopy. The possibility of such ligands to form complexes of L:Eu = 1:2 stoichiometry is revealed.

Phenanthroline diamides (

The fact of the fracture of the extraction curve of lanthanides by 1,10-phenanthroline-2,9-diamides is explained in terms of the structure of complexes, solvent extraction data and quantum chemical calculations. The solvent extraction proceeds in two competing directions: in the form of neutral complexes LLn(NO3)3 and in the form of tight ion pairs {[LLn(NO3)2 H2O]+ (NO3−).

Three pyrrolidine-derived phenanthroline diamides were studied as ligands for lutetium trinitrate. The structural features of the complexes have been studied using various spectral methods and X-ray. The presence of halogen atoms in the structure of phenanthroline ligands has a significant impact on both the coordination number of lutetium and the number of solvate water molecules in the internal coordination sphere. The stability constants of complexes with La(NO3)3, Nd(NO3)3, Eu(NO3)3, and Lu(NO3)3 were measured to demonstrate higher efficiency of fluorinated ligands. NMR titration was performed for this ligand, and it was found that complexation with lutetium leads to an approximately 13 ppm shift of the corresponding signal in the 19F NMR spectrum. The possibility of formation of a polymeric oxo-complex of this ligand with lutetium nitrate was demonstrated. Experiments on the liquid–liquid extraction of Am(III) and Ln(III) nitrates were carried out to demonstrate advantageous features of chlorinated and fluorinated pyrrolidine diamides.

Development of efficient extractants for the separation of actinides and lanthanides in the technologies of nuclear fuel cycle is one of the most urgent and complex tasks in modern nuclear energetics. New family of 4,7-dichloro-1,10-phenanthroline-2,9-dicarboxylic acid diamides based on cyclic amines was synthesized and shown to exhibit high selectivity in the La/Am pair separation (SF (Am/La ≈ 10)) and in the Am/Eu pair separation (SF (Am/Eu ≈ 12)). It was shown that pyrrolidine derived diamide is more efficient extractant for americium, curium and lanthanides from highly acidic HNO3 solution than its non-cyclic N,N,N′,N′-tetraalkyl analogues. The structures of synthesized compounds were studied in details by IR, NMR spectroscopy, and single crystal X-ray diffraction. According to spectroscopy data, incorporation of aromatic rings to the amide fragment of ligand leads to complex dynamic behavior in solutions what is believed to strongly affect the extraction ability of synthesized ligands.

The interaction of geminal dichlorovinylketones with sodium azide was investigated by NMR and DFT calculations. It was found that the corresponding geminal 3,3-diazidoenones are the resultant species. These highly reactive compounds can be trapped with cyclooctyne to form bis-triazolyl substituted enones. In the absence of a trapping agent, 3,3-diazidoenones do cyclize into 3-azidoisoxazoles with the elimination of molecular nitrogen. The versatile reactivity of the resultant azidoisoxazoles was demonstrated in reactions with phosphorus(III) derivatives, Huisgen 1,3-dipolar cycloaddition and Dimroth cyclization to provide efficient access to a variety of valuable compounds.

3-Azidoisoxazoles react with various active methylene compounds (malononitrile, ethyl cyanoacetate and ethyl acetoacetate) in the presence of base to give hybrid isoxazole–triazole molecules in good to nearly quantitative yields.

A promising ternary copolymer of styrene, isoprene, and butadiene, synthesized by anionic polymerization in solution, was subjected to chemical postpolymerization modification using the following branching and endcapping agents: tin and silicon tetrachlorides, N-methylpyrrolidone, and Michler’s ketone. The combined method of chemical modification of the copolymer performed in the two-stream mode (branching and endcapping), with the subsequent mixing of the streams, is the most efficient.

The reaction of 2-phosphorylalkyl-substituted 1,8-naphthyridines, viz., 2-[2-(diphenylphosphoryl)propan-2-yl]-1,8-naphthyridine (L 1 ) and 2-[2-(diphenylphosphoryl)ethyl]-1,8-naph-thyridine (L 2 ), with lanthanide nitrates (Nd, Eu, or Lu) afforded complexes with the metal-to-ligand molar ratio of 1: 1 and 1: 2. Based on the IR and Raman spectroscopic data, it was found that the coordination of the ligands L 1 and L 2 in all complexes occurs through the P=O group and the nitrogen atoms of the naphthyridine moiety.

The previously unknown 2-(N-phosphorylamino)-substituted 1,8-naphthyridines were synthesized by the direct phosphorylation of 2-amino-5,7-dimethyl-1,8-naphthyridine with phosphoryl chlorides of different structures. The structures of the reaction products were confirmed by mass spectrometry, 1H and 31P NMR spectroscopy, and X-ray diffraction study (for one of the compounds).

The complexes of 2-[2-(diphenylphosphoryl)prop-2-yl]-1,8-naphthyridine ( L ) with lanthanide nitrates Ln(NO 3 ) 3 (Ln = Nd, Eu, Lu) were investigated to elucidate the coordination ability of a novel type of potentially tridentate ligands – phosphorylalkyl substituted naphthyridines. The X-ray crystal structures of [Nd L 3 ] 3+ · 3(NO 3 ) − · MeCN ( 1 ), [Eu L 3 ] 3+ · 3(NO 3 ) − · [Eu(NO 3 ) 3 · 4H 2 O] · MeCN ( 2 ), and [Lu L 3 ] 3+ · 3(NO 3 ) − · [Lu(NO 3 ) 3 · 3H 2 O] · 2 MeCN · 0.5 H 2 O ( 3 ) are reported together with their IR and Raman spectra. All the compounds studied contain isostructural [Ln L 3 ] 3+ cations and three NO 3 − counterions. Coordination of each L appears to be O,N,N tridentate-cyclic and coordination number of Ln is nine. Vibrational spectra of 1 – 3 are also compared with that of free ligand and model compounds.

ISSN 0012-5008, Doklady Chemistry, 2009, Vol. 425, Part 2, pp. 84–87. © Pleiades Publishing, Ltd., 2009.Original Russian Text © P.S. Lemport, E.I. Goryunov, I.B. Goryunova, A.A. Letyushov, A.M. Safiulina, I.G. Tananaev, E.E. Nifant’ ev, B.F. Myasoedov, 2009, published in DokladyAkademii Nauk, 2009, Vol. 425, No. 6, pp. 773–776.

First organophosphorus derivatives of 2-alkyl-and 2,3-alkylene-substituted 1,8-naphthyridines were synthesized by the Friedlander reaction starting from 2-aminonicotinaldehyde and diphenylphosphoryl(cyclo)alkanones, respectively.

A simple and efficient synthetic approach to new oligodentate ligands, 2,6-bis(phosphorylamino)pyridine and related compounds, is based on the reaction of diphenylphosphinic chloride Ph 2 POCl with various diamines.

First 2-(phosphoryl)alkyl-substituted 1,6-naphthyridines have been synthesized by the Friedlander reaction between 4-amino-3-formylpyridine and phosphorus-containing ketones; their structures have been confirmed by 1H, 13C and 31P NMR spectroscopy and X-ray diffraction analysis.

First organophosphorus derivatives of 2-alkyl-and 2,3-alkylene-substituted 1,8-naphthyridines were synthesized by the Friedlander reaction starting from 2-aminonicotinaldehyde and diphenylphosphoryl(cyclo)alkanones, respectively.