Photochemical behavior of polymer complexes based on Eu(III) acrylato(bisdibenzoylmethanate)

The photochemical behavior of monomer and polymer complexes of Eu³⁺ that are based on dibenzoylmethane and acrylic acid has been studied. It has been shown that these complexes differ from their low-molecular-mass analogs by properties: in the course of photolysis, the intensity of luminescence of the studied Eu³⁺ complexes increases by a factor of 1.3 to 2.5. The mechanism describind the effect of the composition of polymer formulation on the rate of photodegradation is discussed.     

Luminescence and magnetic properties of europium(III) carboxylatodibenzoylmethanates

This paper reports on the results of an investigation of the luminescence and magnetic properties of europium(III) carboxylates, which are determined by the structure of the Stark and Zeeman sublevels. It has been established that the energy splittings λ_lum between the ⁷ F ₀ ground level and the ⁷ F ₁ term in the luminescence spectra of these compounds well correlate with the energy splittings λ_magn obtained from magnetochemical measurements.     

Columinescence effect in macromolecular complexes of Eu(III) and Tb(III)

The effect of Y(III) and Gd(III) coactivator ions on the intensity of Eu(III) and Tb(III) luminescence in monomer and polymer mixed-metal complexes was studied. Isomorphic replacement of Eu(III) and Tb(III) ions by Y(III) and Gd(III) ions in macromolecular complexes led to sensitization of Eu(III) and Tb(III) ion luminescence. A mechanism of columinescence was suggested. It involves a charge transfer and the ligand orbitals and the vacant orbitals of Eu(III) and Tb(III) ions and coactivators.     

Optical chemosensor properties of europium(III) tris(β-diketonates)

Interaction between Eu(III) tris(β-diketonates) and ammonia vapors increases the luminescence of Eu(III). A mechanism for the effect of analyte molecules on the intensification of Eu(III) luminescence is proposed. The mechanism includes the displacement of water molecules from the coordination sphere of europium(III).     

Carboxylato-bis-dibenzoylmethanates of europium(III): Luminescence and magnetic properties

The luminescent and magnetic properties of europium(III) carboxylates, determined from the structure of Stark and Zeeman sublevels, are studied. It is found that the values of the λ_lum energy gap between the ground state ⁷ F ₀ and ⁷ F ₁ term in the luminescence spectra and λ_magn obtained from magnetochemical measurements correlate well.     

Sensitization of luminescence of antimony(III) in complexes with 6-methylquinoline in the spectral region of the <Emphasis Type="Italic">A</Emphasis> band

The luminescence properties of complexes of antimony (III) halides with 6-methylquinoline: (C₁₀H₉NH)₄Sb₂Cl₁₀ (I), (C₁₀H₉NH)₃SbBr₆ (II), and (C₁₀H₉NH)₄Sb₂I₁₀ (III) are studied. From analysis of data obtained by UV, photoelectron, and luminescence spectroscopy, it is concluded that the decrease in the energy gap between the highest occupied and lowest unoccupied molecular orbitals of the 6-methylquinoline molecules and antimony (III) halides is responsible for quenching of the luminescence of the 6-methylquinolinium cations and for occurrence of intrinsic luminescence of the antimony (III) ions in going from complex I to complexes II and III.     

Photodecomposition of Eu3+ complexes with macromolecular ligands based on acrylic acid

The spectroluminescent and photochemical properties of Eu³⁺ complexes with copolymers of acrylic acid and alkyl methacrylates were studied. It was found that the photochemical behavior of the macromolecular complexes differs significantly from that of the lowmolecular analogs: in the course of photodecomposition the luminescence intensity of Eu³⁺ noticeably increases rather than diminishes. The efficiency of the luminescence build up of Eu³⁺ depends on the composition and the structure of the initial macromolecular complexes. A low concentration of the metal, low content of acrylic acid, and increase in the length of the alkyl radical of methacrylate favor the enhancement of the efficiency of luminescence build up of the rare-earth ion.Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 9, pp. 1559–1562, September, 1993.     

Energy transfer in luminescent complexes of EuIII and TbIII with homo- and copolymers of acrylic acid and alkyl methacrylates

The influence of the composition and structure of a macromolecular ligand on the efficiency of energy transfer in complexes of Eu^III and Tb^III with ligands based on acrylic acid has been studied. It has been found that a decrease in the size of an alkyl group of methacrylic esters and a low content of acrylic moieties of Eu^III complexes with copolymers increase the efficiency of Eu^III concentration quenching. Insertion of noncoordinative alkyl methacrylate into the polymeric chain results in an increase in the efficiency of energy transfer from Tb³⁺ to Eu³⁺.Translated fromIzvestiya Akademii Nauk. Seriya Klrimicheskaya, No. 6, pp. 1425–1428, June, 1996.     

Synthesis,Structure, and Luminescent Properties of Antimony(III) Complexes with N,N"-Diphenylguanidine

Complexes of antimony(III) halides with N,N"-diphenylguanidine were synthesized for the first time and studied using X-ray diffraction analysis and luminescence spectroscopy. The mechanism of sensitization of Sb³⁺luminescence involving the low-lying state of the charge transfer was proposed.     

Rise of photoluminescence in the photolysis of EuIII complexes with copolymers of acrylic acid and butyl methacrylate

The luminescence and photochemical properties of Eu^III complexes with copolymers of acrylic acid and butyl methacrylate have been studied by luminescence, IR spectroscopy, and EXAFS.Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 5, pp. 958–959, May, 1994.