Chemiluminescence Used in Biochemical Investigations. An Application of the Lanthanide Ions as a Chemiluminescent Probe

This article concerns problems related to chemiluminescence and briefly fluorescence, which will be discussed. It also gives a review of application of the chemiluminescent method in chemistry, biology and medicine, in the absence of lanthanide ions and in their presence

Spectroscopic Characterization of Ethylenediamine-di(o-hydroxyphenyl)acetic Acid and its Complexes with Lanthanide(III) Ions

Binding properties of ethylenediaminedi(o-hydroxyphenyl)acetic acid (EHPG) with lanthanide(III) ions were studied using spectroscopic methods. Luminescence intensity and lifetime of the Tb(III) ion were measured in a wide pH range in order to characterize the Ln-EHPG complexation. The calculated hydration number of the Tb-EHPG system proved the replacement of six water molecules by the EHPG ligand in the inner coordination sphere of Tb(III). Energy transfer from Tb(III) to Eu(III) in the Tb(III)-EHPG-Eu(III) system indicated an existence of only monomeric form of the Tb-EHPG complex. Analysis of the ^1H NMR and FTIR spectra of the EHPG ligand and its complexes with lanthanide(III) ions confirmed the hexadentate manner of EHPG complexation with the lanthanides. The system of Dy(III)-EHPG, showing a linear dependence of luminescence intensity (λ$\text{}_{em}$=578 nm) of Dy(III) on its concentration, in the range of 3.3×10-7 to 1×10-5 mol. l-1, can be applied for spectrofluorimetric determination of Dy(III)

Synthesis and Spectroscopic Study of Europium(III) in Heteropolyanion [EuP5\text{}_{5}W30\text{}_{30}O110\text{}_{110}]12−\text{}^{12-}

The heteropolyanions of Preyssler anion [NaP$\text{}_{5}$W$\text{}_{30}$O$\text{}_{110}$]$\text{}^{14-}$ and its europium-encrypted derivative [EuP$\text{}_{5}$W$\text{}_{30}$O$\text{}_{110}$]$\text{}^{12-}$ were prepared and spectroscopically characterized. The compositions of these heteropolyanions were verified based on the results from elemental and thermogravimetric analysis and the data of spectrophotometric determination of tungsten contents. Absorption in the UV-vis and IR region and luminescence spectra, as well as results of the laser-induced europium ion luminescence spectroscopy, obtained for solid complexes and their solutions, were analysed. Both in solid and solution the europium-encrypted derivative has three water molecules of hydration

Influence of N3−\text{}_{3}^{-} Ions on Chemiluminescence of the Eu(II)/Eu(III)-H2\text{}_{2}O2\text{}_{2} System

The basic system of chemiluminescence investigations of relevant biological and inorganic compounds consists of Eu(II)/Eu(III) - H$\text{}_{2}$O$\text{}_{2}$. In these studies the increase in Eu(III) ion emission intensity usually results from an effective complexation reaction. In the present study, the N$\text{}_{3}^{-}$ ions are used as a ligand. The increase in the chemiluminescence intensity of the Eu(III) ion, the pH influence (in the range of 4.5-7.5) on the chemiluminescence intensity of the Eu(III) ion, as well as the quenching of the $\text{}^{5}$D$\text{}_{0}$ excited state of the Eu(III) ion are observed due to N$\text{}_{3}^{-}$ complexation. Taking into account the well-known Fenton system [Fe(II)/Fe(III) - H$\text{}_{2}$O$\text{}_{2}$], containing additionally the N$\text{}_{3}^{-}$, Eu(III) or Sm(III) ions, we found that the Eu(III) or Sm(III) ions were excited as a result of energy transfer process. A mechanism of the studied reactions is proposed

EPR Study of Gadolinium(III) Complexes with Heteropolyanions: [Gd(SiW11\text{}_{11}O39\text{}_{39})2\text{}_{2}]13−\text{}^{13-} and [GdP5\text{}_{5}W30\text{}_{30}O110\text{}_{110}]12−\text{}^{12-}

The gadolinium complexes: [Gd(SiW$\text{}_{11}$O$\text{}_{39}$)$\text{}_{2}$]$\text{}^{13-}$ [I] and [GdP$\text{}_{5}$W$\text{}_{30}$O$\text{}_{110}$]$\text{}^{12-}$ (Gd-encrypted Preyssler anion) [II] have been chosen for EPR study. This study is a continuation of our recent investigation related to solid gadolinium complexes: β-diketonates and aminopolycarboxylates. The EPR spectra of the Gd-polyoxometalates studied provide much better resolution than those recently studied. The spectra of Gd-polyoxometalates containing 1.7 to 2.5% of Gd(III) do not require an additional computer processing for correct interpretation. It is on the contrary to the β-diketonates and polyaminocarboxylates (with the content of Gd(III) 22-33%) for which the use of the RKU computer program (based on Fourier transform) was necessary in order to enhance the spectra resolution thus improving their correct interpretation. The EPR spectra obtained for the compounds I and II markedly differ from the U-spectrum characteristic of Gd(III) in glasses. Taking into account the spin-Hamiltonian calculations the existence of Gd(III) ion in two different surroundings: in a strong crystal field of rhombic symmetry and in a weak crystal field, is observed. The differences observed between the case I and II seem to be related to a various hydration degree