Metal-Mediated One-Step In Situ Oxidation of 2,9-Dimethyl-1,10-phenanthroline and Formation of Transition-Metal and Lanthanoid Complexes

Metal-Ion Induced In Situ Ligand Oxidation for Self-Assembled Clusters: from Bis(5-(2-pyridine-2-yl)-1,2,4-triazole-3-yl)methane to Alcohol or Ketone

Hydrothermal reactions of metal nitrates and ligand bis(5-(pyridine-2-yl)-1,2,4-triazol-3-yl)methane (H₂ L¹ ) gave three cluster compounds, {Cr₂ }, {Zn₁₂ } and {Fe₈ }. Notably, methylene group of H₂ L¹ was in situ oxidized either to hydroxymethylated (L² -O)^3- in the metallo-ring {Zn₁₂ } or to a rigid carbonylated (L³ =O)^2- in the screw-type {Fe₈ }. In light of comparative experimental results, NO₃^- was deduced to be of a catalytic role in the ligand oxidation. Metal ion could be regarded as an "induced" tool for clusters generation in self-assembly process.

Copper(ii) complexes with phosphorylated 1,10-phenanthrolines: from molecules to infinite supramolecular arrays

Supramolecular architectures based on copper(ii) complexes with diethoxyphosphoryl substituted 1,10-phenanthrolines are reported.

Specific chiral sensing of amino acids using induced circularly polarized luminescence of bis(diimine)dicarboxylic acid europium(III) complexes

The circularly polarized luminescence (CPL) from [Eu(pda)2](-) (pda = 1,10-phenanthroline-2,9-dicarboxylic acid) and [Eu(bda)2](-) (bda = 2,2'-bipyridine-6,6'-dicarboxylic acid) in aqueous solutions containing various amino acids was investigated. The europium(III) complexes exhibited bright-red luminescence assignable to the f-f transition of the Eu(III) ion when irradiated with UV light. Although the luminescence was not circularly polarized in the solid state or in aqueous solutions, in accordance with the achiral crystal structure, the complexes exhibited detectable induced CPL (iCPL) in aqueous solutions containing chiral amino acids. In the presence of L-pyrrolidonecarboxylic acid, both [Eu(pda)2](-) and [Eu(bda)2](-) showed similar iCPL intensity (glum ∼ 0.03 for the (5)D0 → (7)F1 transition at 1 mol·dm(-3) of the amino acid). On the other hand, in the presence of L-histidine or L-arginine, [Eu(pda)2](-) exhibited intense CPL (glum ∼ 0.08 for the (5)D0 → (7)F1 transition at 0.10 mol·dm(-3) of the amino acid), whereas quite weak CPL was observed for [Eu(bda)2](-) under the same conditions (glum < 0.01). On the basis of analysis of the iCPL intensities in the presence of 12 amino acids, [Eu(pda)2](-) was found to be a good chiral CPL probe with high sensitivity (about 10(-2) mol·dm(-3)) and high selectivity for L-histidine at pH 3 and for L-arginine at pH 7. The mechanism of iCPL was evaluated by analysis of the fine structures in the luminescence spectra and the amino acid concentration dependence of glum. For the [Eu(pda)2](-)-histidine/arginine systems, the europium(III) complexes possess coordination structures similar to that in the crystal with slight distortion to form a chiral structure due to specific interaction with two zwitterionic amino acids. This mechanism was in stark contrast to that of the europium(III) complex-pyrrolidonecarboxylic acid system in which one amino acid coordinates to the Eu(III) ion to yield an achiral coordination structure.

Bis(ethanamidinium) (1,10-phen-an-thro-line-2,9-dicarboxyl-ato)manganate(II) hepta-hydrate

In the title complex, (C₂H₇N₂)₂[Mn(C₁₄H₆N₂O₄)₂]·7H₂O, the Mn^II atom is coordinated by four N atoms and four O atoms from two 1,10-phenanthroline-2,9-dicarboxyl­ate ligands in a distorted dodeca­hedral geometry. The double negative charge is balanced by two ethanamidinium cations. A three-dimensional supra­molecular structure is formed through N—H⋯O and O—H⋯O hydrogen bonds and π–π stacking inter­actions [centroid–centroid distance = 3.553 (2) Å].

Synthesis and supramolecular networks of 5,6-dioxo-1,10-phenanthroline-2,9-dicarboxylic acid dihydrate and its first coordination compound cis-diaquachlorido(5,6-dioxo-1,10-phenanthroline-2,9-dicarboxylic acid-κ4O2,N,N',O9)manganese(II) chloride dihydrate

5,6-Dioxo-1,10-phenanthroline-2,9-dicarboxylic acid dihydrate (H(2)pdda·2H(2)O), C(14)H(6)N(2)O(6)·2H(2)O, was obtained by carbonylation of 1,10-phenanthroline-2,9-dicarboxylic acid. Its first coordination compound, [MnCl(C(14)H(6)N(2)O(6))(H(2)O)(2)]Cl·2H(2)O, in which the H(2)pdda ligand remains protonated, was synthesized in aqueous acetic acid. H(2)pdda chelates one water molecule via hydrogen bonds in H(2)pdda·2H(2)O, whereas in the coordination compound it chelates one heptacoordinate Mn(II) atom via coordination bonds. The N atoms in H(2)pdda·2H(2)O and the Cl atoms in the coordination compound are also involved in hydrogen bonds. Extensive hydrogen bonding results in supramolecular networks in both compounds.