1,10-Phenanthroline: a versatile ligand

The NaBr cryptates of five macrobicyclic ligands containing bipyridine (bpy) and phenanthroline (phen) groups, i.e, of [bpy.bpy.bpy] 1 [bpy.bpy.phen] 2 [phen.phen.-phen] 3 [2.1.phen] 4 and [2.2.phen] 5, have been prepared. 1, 2, 4 and 5 have been obtained in high yield by condensation of bis(bromomethyl)bipyridine 6 or -phenanthroline 9 with the corresponding macrocyclic diamines in presence of Na2CO3. Direct access to the NaBr complexes of th symmetrical cryptands 1 and 3 was achieved by a one-step macrobicyclisation procedure. The metal-ion complexes of ligands 1-5 have the attractive feature of combining the cation inclusion, nature of cryptates with the photoactivity of bipyridine and phenanthroline groups; they may thus be expected to posses a variety of interesting physical and chemical properties.

Photoactive cryptands. Synthesis of the sodium cryptates of macrobicyclic ligands containing bipyridine and phenoanthroline groups

In this work, we reported a phenanthroline-based tetradentate ligand with hard-soft donors combined in the same molecule, N,N'-diethyl-N,N'-ditolyl-2,9-diamide-1,10-phenanthroline (Et-Tol-DAPhen), for the group separation of actinides over lanthanides. The synthesis and solvent extraction as well as complexation behaviors of the ligand with actinides and lanthanides are studied experimentally and theoretically. The ligand exhibits excellent extraction ability and high selectivity toward hexavalent, tetravalent, and trivalent actinides over lanthanides in highly acidic solution. The chemical stoichiometry of Th(IV) and U(VI) complexes with Et-Tol-DAPhen is determined to be 1:1 using X-ray crystallography. The stability constants of some typical actinide and lanthanide complexes of Et-Tol-DAPhen are also determined in methanol by UV-vis spectrometry. Density functional theory (DFT) calculations reveal that the An-N bonds of the Et-Tol-DAPhen complexes have more covalent characters than the corresponding Eu-N bonds, which may in turn lead to the selectivity of Et-Tol-DAPhen toward actinides. This ligand possesses merits of both alkylamide and 219-bis-(5,6-dialkyl-1,2,4-triazin-3-yl)-1,10-phenanthroline (R-BTPhen) extractants for efficient actinide extraction and the selectivity toward minor actinides over lanthanides and hence renders huge potential opportunities in high-level liquid waste (HLLW) partitioning.

Excellent selectivity for actinides with a tetradentate 2,9-diamide-1,10-phenanthroline ligand in highly acidic solution: a hard-soft donor combined strategy.

Modeling Carboxylate-Bridged Dinuclear Active Sites in Metalloenzymes Using a Novel Naphthyridine-Based Dinucleating Ligand

The new 1,10-phenanthroline containing 1:1 proton−transfer compound LH2, [pyda·H2]2+[phendc]2-, was synthesized from the reaction of 2,6-pyridinediamine, pyda, and 1,10-phenanthroline-2,9-dicarboxylic acid, phendc·H2, and characterized by elemental analysis, ES−Ms, IR, 1H, 13C NMR, and UV/vis spectroscopies. Subsequently, the first example of [phendc]2- containing anionic complex [pyda·H]2[Co(phendc)2]·10H2O, was prepared, using the above novel proton-transfer compound, and structurally characterized by single-crystal X-ray diffraction. The complex crystallizes in the space group P21/n of the monoclinic system with four molecules in a unit cell of dimensions a = 11.877(3) A, b = 31.473(9) A, c = 12.915(4) A, and β = 116.223(5)°. The structure has been refined to a final value for the crystallographic R factor of 0.0524 based on 9021 observed independent reflections. The complexation reactions of pyda, phendc·H2, and LH2 with H+ as well as LH2 with Co(II) in aqueous solution were investigated by potentiome...

First Anionic 1,10-Phenanthroline-2,9-dicarboxylate Containing Metal Complex Obtained from a Novel 1:1 Proton−Transfer Compound: Synthesis, Characterization, Crystal Structure, and Solution Studies

Vasilios Tzimos

Papers

The synthesis of macrocyclic polyether-diesters incorporating 1,10-phenanthrolino and 1,8-naphthyridino subunits