A. N. Zadorozhnaya

The Fluorescent Properties of Heteroligand Europium Cinnamates

Heteroligand europium cinnamates with nitrogen- and phosphorus-containing neutral ligands were studied by luminescent and X-ray electron spectroscopy. A tendency toward an increase in the electron density on Eu3+ was observed when neutral ligands were coordinated by donor nitrogen atoms. The Δν0, ΔF1, and I(F0)/I(F2) values monotonically decreased as the donor properties of neutral ligands increased because of strengthening of the interaction of Eu3+ with the ligands.

The dispersity and distribution of luminophors in high-pressure polyethylene

Polymers based on high-pressure polyethylene were prepared and activated with europium(III) complexes with carboxylic acids and compositions based on europium-anthranilic acid compounds. According to the electron scanning, atomic, and fluorescence spectroscopic data, luminophor particles showed a heterophase distribution in films. The particles had an average size of 3–30 μm and were shaped as globules.

Crystal and molecular structure and luminescence properties of the europium trifluoroacetate complex with dipyridyl

The crystal structure of [Eu(Dipy)(TFA)3(H2O)3] · Dipy (where TFA− is the trifluoroacetate anion and Dipy is, 2,2′-dipyridyl) has been studied by X-ray diffraction. The coordination polyhedron of the europium atom is a distorted square antiprism [EuO6N2] with the nonplanar quadrilateral faces. The coordinated and non-coordinated dipyridyl molecules are linked pairwise through π stacking interactions into an infinite pile with an overlap of up to 50% of the molecular surface areas. An increase in the luminescence intensity of the compound upon its UV irradiation is explained.

Photochemical behavior of lanthanide-containing polymer materials

Light-transforming polymer materials activated by compositions based on the mixed-ligand europium carboxylates and anthranilic acid exhibiting an intense luminescence in the spectral region 400–700 nm are prepared. The photolysis of the polymer materials is investigated. For the obtained compositions the flaring of intensity of luminescence of europium ion and anthranilic acid was detected.

The Luminescent Properties of Polyethylene Films with Admixtures of Luminophores Based on Europium Compounds

Polyethylene films activated with europium(III) complexes with carboxylic acids and Eu(L)3 · nD · xH2O + ANT compositions, where L is the trifluoroacetic, toluyl, or cinnamic acid anion and ANT is anthranilic acid, were prepared. The intensity of luminescence of the polymeric compositions depended on the content of luminophores (molar ratio between europium compounds and anthranilic acid). An analysis of the excitation spectra showed that, in polymer—Eu(L)3 · nPhen · xH2O + ANT compositions, there was effective energy transfer from phenanthroline to anthranilic acid levels.

Photochemical properties of mixed-ligand europium compounds of Eu(C10H11F7O2)3D composition

The intensively luminescing mixed-ligand europium compounds were synthesized of the composition Eu(C10H11F7O2)3D, where C10H11F7O2 is heptafluorodimethyloctanedione, D is either 1,10-phenanthroline (C12H8N2), triphenylphosphine oxide (C18H15PO), hexamethylphosphoramide (C6H18N3PO), benzotriazole (C6H5N3), or phenylguanidine [(C6H5NH)2 =NH]. The luminescent properties of europium compounds in the crystalline state and in a polymer matrix of high-pressure polyethylene (HPPE) and polyvinyl chloride (PVC) and kinetics of the luminescence intensity decay under UV radiation were studied. The most photo-resistant in HDPE and PVC was found to be Eu(C10H11F7O2)3Ph3PO.

Photolysis of light-transforming polymer material

Light-transforming polymer materials activated with the compositions on the basis of the europium carboxylates with different ligands and anthranilic acid exhibiting the intense luminescence in the spectral range 400–700 nm are prepared. It is shown that light stability of polymer materials on the basis of the aboveprepared compositions is higher than of polymer materials activated with the europium salts. The photolysis of luminescent polymers was studied. For the compositions EuL3C13H13N3·xH2O + anthranilic acid gradual increase in the luminescence intensity of the europium ion is marked.

Luminescence of europium trifluoroacetates

The luminescence spectral characteristics of mixed-ligand europium trifluoroacetates with nitrogen- and phosphorus-containing neutral ligands were studied at different temperatures. For several trifluoroacetates, the intensity of luminescence increased with temperature. The diffuse reflectance data were analyzed, and a mechanism of thermal luminescence buildup was suggested.