V. E. Karasev

Crystal structure and excimer fluorescence of dibenzoylmethanatoboron difluoride

Fluorescence properties of dilute and concentrated solutions of dibenzoylmethanatoboron difluoride and its crystals were studied. Excimers are formed in concentrated solutions and crystals of dibenzoylmethanatoboron difluoride. The crystal structure of dibenzoylmethanatoboron difluoride was determined by X-ray diffraction analysis. It was found that the molecules of dibenzoylmethanatoboron difluoride are coplanar with an interplanar distance of 3.6 Å.

Fluorescence and photochemical properties of crystalline boron difluorides β-diketonato

The fluorescence and photochemical properties of crystalline β-diketonatoboron difluorides (DBD) RCOCHCOR1BF2 were studied. These compounds are characterized by relatively high photochemical stability. The introduction of electron-donating groups into the aromatic α-substituent of the chelate ring increases and the introduction of electron-withdrawing groups decreases the fluorescence intensity of DBD. Anisoylbenzoylmethanotoboron difluoride was found to exhibit the highest fluorescence intensity. The substituents were shown to influence the relative arrangement of singlet and triplet ηπ* and ππ* levels and luminescence properties of compounds.

Crystal Structure and Luminescence of the [Eu(Phen)2(NO3)3] Complex. The Role of the Ion-Coactivator

The [Eu(Phen)2(NO3)3] complex was synthesized via reaction of europium nitrate with 1,10-phenanthroline (Phen) and studied by X-ray diffraction analysis. The crystals are monoclinic: a= 11.168(1), b= 17.976(2), c= 13.053(1) Å, β = 100.577(2)°, space group C2/c, Z= 4, ρ(calcd) = 1.801 g/cm3. The central europium atom coordinates (on a two-fold axis) six oxygen atoms of three nitrate groups with distances of 2.499(2), 2.502(2), and 2.542(2) Å and four nitrogen atoms of two phenanthroline molecules with distances of 2.542(2) and 2.593(2) Å. The influence of ion-coactivators on the luminescence of Eu3+in the [EuxM1 - x(Phen)2(NO3)3] complexes (M = Y, La, Nd, and Lu) is discussed.

Excimer formation of dibenzoylmethanatoboron difluoride during photolysis in polymer films

ABSTRACT Photochemical behavior of polyethylene, polystyrene and polymethylmethacrylate films containing dibenzoylmethanatoboron difluoride was investigated. It was observed that during UV irradiation of polyethylene films the monomer fluorescence of the complex (λ max=450 nm) transforms into excimer fluorescence (λ max=535 nm).

Sensitization of luminescence of antimony(III) in complexes with 6-methylquinoline in the spectral region of the A 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.

Lanthanide-Containing Monomers Produced from Unsaturated Acids: Synthesis, Polymerization, and Spectral and Luminescent Properties. Crystal Structure of Europium(III) Methacrylate

Synthesis of lanthanide-containing (Ln = Eu, Tb, Nd, Gd) monomers based on unsaturated acids is described, namely, of LnL13 · nH2O (L1 are anions of acrylic and methacrylic acids) and Ln2L23 · nH2O (L2 are anions of maleic and fumaric acids); n = 0–3, 6. The compounds were characterized by elemental analysis, thermogravimetry, and IR and luminescence spectroscopy. Europium methacrylate Eu(Macr)3 was studied using X-ray diffraction analysis: rhombic system, a = 14.831(3) Å, b = 12.964(2) Å, c = 7.761(1) Å, space group Cmc21, V = 1483.5(4) Å3, ρ(calcd) = 1.823 g/cm3. Infinite chains of Eu(Macr)3 molecules are directed along crystallographic axis c and are bound by van der Waals interactions. Radical polymerization of Eu(III) and Tb(III) acrylates and Eu(III) methacrylate yields lanthanide-containing polymers with a high content of Ln (40–50 mass %). Their spectral and luminescent properties are studied.

Antimony(III) Chloride Complexes with Benzylpyridines: Synthesis and Luminescence. Crystal Structure of Bis(2-benzylpyridinium) Pentachloroantimonate(III)

AbstractThe antimony(III) chloride complexes with 2- and 4-benzylpyridine were synthesized and studied using elemental analysis, X-ray diffraction analysis, IR spectroscopy, and luminescence spectroscopy. The crystal structure of bis(2-benzylpyridinium) pentachloroantimonate(III) was determined. The crystals are triclinic: a = 9.628(1) Å, b = 15.284(2) Å, c = 19.174(2) Å, α = 99.962(2)°, β = 101.233(2)°, γ = 99. 216(2)°; Z = 4, ρ(calcd) = 1.591 g/cm3, space group P

Europium(III) Acrylatodibenzoylmethanate: Synthesis, Spectroscopy (IR, Luminescence), and Polymerization Properties

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