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1,10-phenanthroline based-preorganized ligand

Mark A Lashley, Alexander S Ivanov, Vyacheslav S Bryantsev, Sheng Dai, Robert D Hancock
Studies of the complexation of new promising ligands with uranyl (UO2 2+ ) and other seawater cations can aid the development of more efficient, selective, and robust sorbents for the recovery of uranium from seawater. In this work, we propose that the ligand design principles based on structural preorganization can be successfully applied to obtain a dramatic enhancement in UO2 2+ ion binding affinity and selectivity. This concept is exemplified through the investigation of the complexes of UO2 2+ , VO2 + , and VO2+ with the highly preorganized ligand 1,10-phenanthroline-2,9-dicarboxylic acid (PDA) using a combination of fluorescence and absorbance techniques, along with density functional theory (DFT) calculations...
October 17, 2016: Inorganic Chemistry
Ashley N Carolan, Gregory M Cockrell, Neil J Williams, Gang Zhang, Donald G VanDerveer, Hee-Seung Lee, Randolph P Thummel, Robert D Hancock
Some metal ion complexing properties of DPP (2,9-Di(pyrid-2-yl)-1,10-phenanthroline) are reported with a variety of Ln(III) (Lanthanide(III)) ions and alkali earth metal ions, as well as the uranyl(VI) cation. The intense π-π* transitions in the absorption spectra of aqueous solutions of 10(-5) M DPP were monitored as a function of pH and metal ion concentration to determine formation constants of the alkali-earth metal ions and Ln(III) (Ln = lanthanide) ions. It was found that log K(1)(DPP) for the Ln(III) ions has a peak at Ln(III) = Sm(III) in a plot of log K(1) versus 1/r(+) (r(+) = ionic radius for 8-coordination)...
January 7, 2013: Inorganic Chemistry
Robert D Hancock
Factors in polypyridyl ligands that control their thermodynamic metal ion selectivity in aqueous solution, and their use in selective fluorescent sensing, are examined. Preorganization of polypyridyl ligands ranging from bidentate to tetradentate by bridging benzo groups, as are present in 1,10-phenanthroline (phen) compared to 2,2'-bipyridyl (bpy), is discussed. The role of solvation is considered in relation to the relative affinity of ligands containing pyridyl groups for divalent and trivalent metal ions in aqueous solution...
February 21, 2013: Chemical Society Reviews
Debashree Manna, Tapan K Ghanty
We have investigated the complexation behavior of preorganized 1,10-phenanthroline-2,9-dicarboxylic acid (PDA) based ligands with trivalent lanthanides and actinides using density functional theory with various GGA type exchange-correlation functionals and different basis sets. New ligands have been designed from PDA through functionalization with soft donor atoms such as sulfur, resulting in mono-thio-dicarboxylic acids (TCA/TCA1) and di-thio-dicarboxylic acid (THIO). It has been found that selectivity in terms of complexation energy of actinides over lanthanides is the maximum with TCA1 where the metal-ligand binding is through the O atoms...
August 21, 2012: Physical Chemistry Chemical Physics: PCCP
Danielle Merrill, James M Harrington, Hee-Seung Lee, Robert D Hancock
Some metal ion complexing properties of the ligand PDAM (1,10-phenanthroline-2,9-dicarboxamide) in aqueous solution are reported. Using UV-visible spectroscopy to follow the intense π-π* transitions of PDAM as a function of metal ion concentration, log K(1) values in 0.1 M NaClO(4) and at 25 °C are, for Cu(II), 3.56(5); Ni(II), 3.06(5); Zn(II), 3.77(5); Co(II), 3.8(1); Mg(II), 0.1(1); Ca(II), 1.94(4); and Ba(II), 0.7(1). For more strongly bound metal ions, competition reactions between PDAM and EDTA (ethylenedinitrilo-tetraacetic acid) or tetren (1,4,7,10,13-pentaazatridecane), monitored following the UV spectrum of PDAM, gave the following log K(1) values in 0...
September 5, 2011: Inorganic Chemistry
Neil J Williams, Nolan E Dean, Donald G VanDerveer, Robert C Luckay, Robert D Hancock
The selectivity of the rigid ligand PDA (1,10-phenanthroline-2,9-dicarboxylic acid) for some M(III) (M = metal) ions is presented. The structure of [Fe(PDA(H)(1/2))(H(2)O)(3)] (ClO(4))(2).3H(2)O.(1)/(2)H(5)O(2) (1) is reported: triclinic, P1, a = 7.9022(16) A, b = 12.389(3) A, c = 13.031(3) A, alpha = 82.55(3) degrees , beta = 88.41(3) degrees , gamma = 78.27(3) degrees , V = 1238.6(4) A(3), Z = 2, R = 0.0489. The coordination geometry around the Fe(III) is close to a regular pentagonal bipyramid, with Fe-N lengths averaging 2...
August 17, 2009: Inorganic Chemistry
Darren L Melton, Donald G Vanderveer, Robert D Hancock
The metal ion-complexing properties of 1,10-phenanthroline-2,9-dicarboxylic acid (PDA) are reported. The protonation constants (pK1 = 4.75, pK2 = 2.53) and formation constants (log K(1)) for PDA with Mg(II) (3.53), Ca(II) (7.3), Sr(II) (5.61), Ba(II) (5.43), La(III) (13.5), Gd(III) (16.1), Zn(II) (11.0), Cd(II) (12.8), Pb(II) (11.4), and Cu(II) (12.8) were determined by UV-vis spectroscopy in 0.1 M NaClO4 at 25 degrees C. The log K(1) values for most of these metal ions were high enough that they were not displaced from their PDA complexes even at pH 2...
November 13, 2006: Inorganic Chemistry
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