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Full-Text Articles in Physical Sciences and Mathematics
Speciation, Luminescence, And Alkaline Fluorescence Quenching Of 4-(2-Methylbutyl)Aminodipicolinic Acid (H2mebadpa), Gilles Muller, A. J. Ingram, A. G. Dunpal, R. Dipietro
Speciation, Luminescence, And Alkaline Fluorescence Quenching Of 4-(2-Methylbutyl)Aminodipicolinic Acid (H2mebadpa), Gilles Muller, A. J. Ingram, A. G. Dunpal, R. Dipietro
Gilles Muller
4-(2-Methylbutyl)aminodipicolinic acid (H2MEBADPA) has been synthesized and fully characterized in terms of aqueous phase protonation constants (pKa's) and photophysical measurements. The pKa's were determined by spectrophotometric titrations, utilizing a fully sealed titration system. Photophysical measurements consisted of room temperature fluorescence and frozen solution phosphorescence as well as quantum yield determinations at various pH, which showed that only fully deprotonated MEBADPA2– is appreciably emissive. The fluorescence of MEBADPA2– has been determined to be quenched by hydroxide and methoxide anions, most likely through base-catalyzed excited-state tautomerism or proton transfer. This quenching phenomenon has been quantitatively explored through steady-state and time-resolved fluorescence measurements. …
A Promising Change In The Selection Of The Circular Polarization Excitation Used In The Measurement Of Eu(Iii) Circularly Polarized Luminescence, K. Do, F. C. Muller, Gilles Muller
A Promising Change In The Selection Of The Circular Polarization Excitation Used In The Measurement Of Eu(Iii) Circularly Polarized Luminescence, K. Do, F. C. Muller, Gilles Muller
Gilles Muller
A judicious change in the selected transition used for circular polarization excitation will overcome the low oscillator strength limitation of the currently allowed magnetic-dipole 5D1 ← 7F2 (Eu(III)) transition chosen for circularly polarized luminescence (CPL) measurement. The proposed allowed magnetic-dipole 5D1 ← 7F0 (Eu(III)) transition will facilitate the detection of CPL from the Eu(III) systems of interest. CPL on the acetonitrile solution of the chiral tris complex of Eu(III) with (R,R)-N,N′-bis(1-phenylethyl)-2,6-pyridinedicarboxamide ([Eu((R,R)-1)3]3+), recently suggested as an effective and reliable CPL calibrating agent, confirms the feasibility of the proposed experimental procedure. A comparable CPL activity exhibited by the acetonitrile solution of …
Characterization Of The Electronic Excited-State Energetics And Solution Structure Of Lanthanide(Iii) Complexes With The Polypyridine Ligand 6,6'-Bis[Bis(2-Pyridylmethyl)Aminomethyl]-2,2'-Bipyridine, Gilles Muller, P. Gawryszewska, J. Sokolnicki, A. Dossing, J. P. Riehl, J. Legendziewicz
Characterization Of The Electronic Excited-State Energetics And Solution Structure Of Lanthanide(Iii) Complexes With The Polypyridine Ligand 6,6'-Bis[Bis(2-Pyridylmethyl)Aminomethyl]-2,2'-Bipyridine, Gilles Muller, P. Gawryszewska, J. Sokolnicki, A. Dossing, J. P. Riehl, J. Legendziewicz
Gilles Muller
Absorption, emission, and excitation spectra for solid-state and solution of Tb(III), Dy(III), and Gd(III) complexes with the polypyridine ligand 6,6‘-bis[bis(2-pyridylmethyl)-aminomethyl]-2,2‘-bipyridine (C36H34N8) are presented. Measurements of excited-state lifetimes and quantum yields in various solvents at room temperature and 77 K are also reported and used to characterize the excited-state energetics of this system. Special attention is given to the characterization of metal-to-ligand energy transfer efficiency and mechanisms. The measurement of circularly polarized luminescence (CPL) from the solution of the Dy(III) complex following circularly polarized excitation confirms the chiral structure of the complexes under study. No CPL is present in the luminescence …
Lanthanide Spectroscopic Studies Of The Dinuclear And Mg(Ii)-Dependent Pvuii Restriction Endonuclease, Gilles Muller, L. M. Bowen, J. P. Riehl, C. M. Dupureur
Lanthanide Spectroscopic Studies Of The Dinuclear And Mg(Ii)-Dependent Pvuii Restriction Endonuclease, Gilles Muller, L. M. Bowen, J. P. Riehl, C. M. Dupureur
Gilles Muller
Type II restriction enzymes are homodimeric systems that bind four to eight base pair palindromic recognition sequences of DNA and catalyze metal ion-dependent phosphodiester cleavage. While Mg(II) is required for cleavage in these enzymes, in some systems Ca(II) promotes avid substrate binding and sequence discrimination. These properties make them useful model systems for understanding the roles of alkaline earth metal ions in nucleic acid processing. We have previously shown that two Ca(II) ions stimulate DNA binding by PvuII endonuclease and that the trivalent lanthanide ions Tb(III) and Eu(III) support subnanomolar DNA binding in this system. Here we capitalize on this …
Temperature And Pressure Dependence Of Excitation Spectra As A Probe Of The Solution Structure And Equilibrium Thermodynamics Of A Eu(Iii) Complex Containing A Modified Dota Ligand, Gilles Muller, S. D. Kean, D. Parker, J. P. Riehl
Temperature And Pressure Dependence Of Excitation Spectra As A Probe Of The Solution Structure And Equilibrium Thermodynamics Of A Eu(Iii) Complex Containing A Modified Dota Ligand, Gilles Muller, S. D. Kean, D. Parker, J. P. Riehl
Gilles Muller
No abstract provided.