Influence of the steric effect on the spectral properties of benzoylacetonatoboron difluorides

The structures and spectral luminescence properties of two similar in structure β-diketonatoboron difluorides were studied in comparison. One of them (1-(2,4,6-trimethyl-phenyl)butane-1,3-dionatoboron difluoride (1)) contains two methyl groups in the both ortho-positions of the phenyl ring, which excludes the formation of rotamers with the planar configuration. In the second compound, 1-phenylbutane-1,3-dionatoboron difluoride (2), the α-phenyl substituent can rotate freely. The steric factor exerts no effect on monomer fluorescence but substantially affects the ability of benzoylacetonatoboron difluorides to undergo intermolecular interactions, which leads to considerable differences in the luminescence properties of concentrated solutions and crystals of compounds 1 and 2.     

Luminescence and magnetic properties of europium(III) nitrate complex with 1,10-phenanthroline

Luminescent and magnetic properties of the europium nitrate complex with 1,10-phenanthroline synthesized in the traditional way by precipitation from water-ethanol medium and by the method of mechanical activation were investigated. Correlations between luminescent and magnetic properties of the complex compounds were revealed. The higher value of molar magnetic susceptibility ??_m was shown to be typical for the highly dispersed europium compound obtained by mechanochemistry method due to the presence of the paramagnetic ion Eu²⁺.     

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

Eu(III) acrylatodibenzoylmethanate was synthesized with the aim of obtaining luminescent macromolecular Ln(III) complexes with chromophores. It was homo- and copolymerized with methyl methacrylate. The compounds formed were characterized by elemental analysis, luminescence, and IR spectroscopy. The luminescence intensity of the macromolecular Eu(III) complexes containing dibenzoylmethanate ions was shown to exceed the intensity of the monomeric complex by several times. The increase in the luminescence intensity when going from the monomer to copolymers is explained by the weakening of the quenching effect of the low state of the metal–ligand charge transfer.     

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

The 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, = 99.962(2)°, = 101.233(2)°, = 99. 216(2)°; Z = 4, (calcd) = 1.591 g/cm³, space group P , R = 0.0358. The structure consists of polymeric chains of [Sb₂Cl₁₀]^4n– _n anions and [C₁₂H₁₁NH]⁺ cations combined into a framework by the N–H···Cl hydrogen bonds. The electronic and geometrical factors responsible for a relatively low intensity of the luminescence emitted by the complexes of antimony(III) chloride with 2- and 4-benzylpyridine at 77 K are discussed.     

Photochemical behavior of luminescent compositions based on antimony(III) and europium(III) complexes in high-pressure polyethylene

Luminescent and photochemical properties of polymer compositions based on the Eu(NO₃)₃(Phen)₂ complex and complexes of antimony(III) halides with diphenylguanidine are investigated. It is found that high-pressure polyethylene (HPPE) containing europium(III) and antimony(III) complexes in combination exhibits efficient transfer of electronic excitation energy from antimony(III) levels to europium(III) levels and photosensitization of europium(III) luminescence. It is shown that the europium(III) and antimony(III) complexes increase the stability of HPPE to UV radiation.     

Luminescence of antimony(III) halide complexes with aniline

The antimony(III) chloride and bromide complexes with aniline, (C₆H₅NH₃)₂SbCl₅·(C₆H₅NH₃)Cl·H₂O (I) and (C₆H₅NH₃)₂SbBr₅ (II), were synthesized, and their spectral luminescence properties were studied. An interesting peculiarity of I and II is the possibility of selective excitation of luminescence in the π system of the (C₆H₅NH₃)⁺ outer sphere anilinium cation and intrinsic luminescence of the s ² ion. The population scheme for the luminescent antimony ³ P ₁ level in I and II is discussed using the luminescence, UV, and photoelectron spectroscopy data. Original Russian Text ? T.V. Sedakova, A.G. Mirochnik, V.E. Karasev, 2009, published in Zhurnal Fizicheskoi Khimii, 2009, Vol. 83, No. 2, pp. 380–382.     

Antimony(III) Complexes with Quaternary Ammonium Bases: Synthesis, Spectral, and Luminescent Properties

Complexes of antimony(III) halides with quaternary ammonium bases of different composition were synthesized and characterized by elemental and X-ray diffraction analyses and IR and luminescence spectroscopy. For complexes [R"₃R"N]SbHal₄ (Hal = Cl^–, Br^–, R" = R" = CH₃, C₂H₅, C₄H₉), the maximum of the emission band and fluorescence intensity was found to depend on the nature of the halide ion and the alkyl radical length.