State and Stability of Erbium(III) and Dysprosium(III) Complexes of Octaphenyltetraazaporphine in Proton-Donor Media

The acid-base interaction of chloro(octaphenyltetraazaporphinato)erbium(III), (acetylacetonato)(octaphenyltetraazaporphinato)erbium(III), and (acetylacetonato)(octaphenyltetraazaporphinato)dysprosium(III) in AcOH and in AcOH-benzene and AcOH-H₂SO₄ systems involves one meso-nitrogen atom of the complexes; the stability constants of the resulting acid forms were estimated. The solvoprotolytic dissociation of the complexes in the AcOH-H₂SO₄ system was studied, its kinetic parameters were determined, and some suggestions as to the dissociation mechanism were made.     

Rhodium(III) and Iridium(III) Complexes with Octaphenyltetraazaporphine: Synthesis and Study of Their Acid Forms in Proton-Donor Media

The Rh(III) and Ir(III) complexes with octaphenyltetraazaporphine (X)MOPTAP (M = Rh, X = HSO₄, OH; M = Ir, X = HSO₄) are synthesized and their specific acid–base interactions in the CF₃COOH–CH₂Cl₂ and H₂SO₄–CH₃COOH systems are studied. The quantitative characteristics of equilibria between the acid and basic forms are obtained. The stability constants K ₁ of the first acid forms, in which one of the meso-N atom is protonated, for hydrosulfate (HSO₄)MOPTAP complexes in the H₂SO₄–CH₃COOH mixture are equal to –0.54 (Rh) and 0.0057 (Ir). The Ir complexes have more basic meso-N atoms due to more strong -backbonding effect of coordination and, therefore, the second protonation stage (K ₂ = –4.25) could be also observed. In the CF₃COOH–CH₂Cl₂ mixture, the basic properties of the meso-N atoms are levelled out. For (HSO₄)RhOPTAP K ₁ = 1.35, while for (HSO₄)IrOPTAP K ₁ = 1.24 and K ₂ = 0.45.     

Mixed-Ligand Europium(III) Complexes with 4-Methylbenzoic Acid

Russian Journal of General Chemistry - Europium(III) complexes with p-methylbenzoic acid and nitrogen- or phosphorus-containing neutral ligand with the compositions [Eu(p-MBA)3·D]2·xH2O...     

Luminescence Spectral Properties of Europium(III) and Terbium(III) Complexes with Cinnamic Acid

Europium and terbium mixed-ligand complexes with cinnamic acid of composition Ln(Cin)₃· nD · xH₂O, where Ln = Eu³⁺or Tb³⁺, Cin is a cinnamate ion (C₆H₅CH=CHCOO^–), D = 1,10-phenantroline, 2,2"-dipyridyl, benzotriazole (n= 2, x= 0), triphenylphosphine oxide (n= 1, x= 2), or H₂O (n= 0 or 1, x= 0), were synthesized. The compounds were characterized by elemental analysis, IR and luminescence spectroscopy. The Stark structure of the ⁵ D ₀–⁷ F _j(j= 0, 1, 2) electronic transitions in the low-temperature luminescence spectra of europium complexes was analyzed. IR study has revealed a bidentate coordination of the cinnamate ion in the compounds.     

Complexes of Oxamic Acid with La(III), Gd(III), Tb(III), Er(III), Tm(III) and Lu(III)

The preparation, for the first time, of the deprotonated complexes of oxamic acid with La(III), Gd(III), Tb(III), Er(III), Tm(III) and Lu(III) is reported. Analytical results, conductometric measurements, magnetic moments and spectral data (IR and diffuse reflectance spectra) are discussed in terms of possible structural types. The oxamate anion acts as a N, O bidentate non-bridging ligand.     

Manganese Complexes with Octaphenyltetraazaporphine: Acid–Base Interactions and Kinetic Stability in Proton-Donor Solvents

Complexes of manganese(III) and manganese(V) with octaphenyltetraazaporphine (H₂OPTAP) were synthesized. Acid–base interactions of these complexes in the CH₂Cl₂–CF₃COOH system and kinetics of their dissociation in concentrated sulfuric acid, as well as kinetics of octaphenyltetraazaporphine destruction in sulfuric acid solutions were studied by spectrophotometric methods. Acid–base interactions in CH₂Cl₂–CF₃COOH were shown to involve two macrocyclic meso-nitrogen atoms in succession. Concentration stability constants of the acid forms obtained pK ₁ = 0.29 ± 0.01 and pK ₂ = –0.62 ± 0.08 for (chlorine)manganese(III)octaphenyltetraazaporphine ((Cl)MnOPTAP); pK ₁ = 0.99 ± 0.02 and pK ₂ = – 0.70 ± 0.03 for (nitrido)manganese(V)octaphenyltetraazaporphine ((N)MnOPTAP). The rate of dissociation of the complexes in 94–98% H₂SO₄ does not depend on the acid concentration. The manganese(V) complex is three times as stable as the manganese(III) complex.     

铕(III)三元配合物荧光性质的研究

According to fluorescent spectra of a series of Eu(III) ternary complexes in the three solvents EtOH, DMF and CH3CN, the fluorescence is stronger in the solvent CH3CN than in the solvents EtOH and DMF, and fluorescent intensity is contrary to the affinity of three solvents with rare earth ions. Center ions emit fluorescence mainly by an intramolecular energy transfer from the broad absorbing β-diketonate TTA, BTA or BA to the chelated rare earth ions.     

三种新的铕(III)三元配合物的合成及发光性质研究

合成了吡嗪 [2 ,3 f]并邻菲罗啉及其一系列衍生物 ,作为第二配体 ,并以二苯甲酰甲烷为第一配体 ,合成了 3种新的铕 (III)三元配合物 .通过元素分析、红外光谱、核磁共振光谱确定了它们的组成 ,研究了三种配合物的热稳定性、成膜性能和光致发光性能 (发光强度、荧光量子效率和寿命 ) ,并初步从理论上探讨含有不同基团的第二配体的结构对铕 (III)配合物发光的影响 ,结果表明 :这三种铕 (III)三元配合物均为优良的红色发光材料 ,而且在真空条件下均形成均衡的薄膜 ,这为以这三种铕 (III)配合物作为发光层材料制作有机电致发光器件提供了认识基础     

Complexes of gallium(III), antimony(III), titanium(IV), and cobalt(II) with acenaphthenequinonimine

Reactions of (2,6-diisopropylphenylimino)acenaphthenone (dpp-mian) with gallium(III), antimony(III), titanium(IV), and cobalt(II) chlorides in toluene lead to the formation of compounds of the formulas [(dpp-mian)₂GaCl₂][GaCl₄], (dpp-mian)SbCl₃, (dpp-mian)TiCl₄, and [(dpp-mian)CoCl₂]₂[CoCl₂(EtOH)₄], respectively. The complexes were characterized by IR and NMR spectra, their structure was established by X-ray crystallography.     

Spectroscopic and Crystal Structure of Europium(III) Picrate Complexes with Novel BINOL Derivatives

Two novel ligands N‐Benzyl‐2‐{2′‐[(benzyl‐phenyl‐carbamoyl)‐methoxy]‐[1,1′]binaphthalenyl‐2‐yloxy}‐N‐phenyl‐acetamide (L1) and N‐Methyl‐2‐{2′‐[(methyl‐phenyl‐carbamoyl)‐methoxy]‐[1,1′]binaphthalenyl‐2‐yloxy}‐N‐phenyl‐acetamide (L2), and their europium(III) complexes with picrate, [Eu(pic)₃(L1)] and [Eu(pic)₃(L2)], were synthesized and characterized by elemental analysis, IR, UV‐Vis and fluorescence spectroscopy. The crystal structure of [Eu(pic)₃(L1)]·2CHCl₃ was determined by single crystal X‐ray diffraction. The europium atom is coordinated by nine oxygen atoms of four from the L1 and five from two bidentate and one unidentate picrates. The fluorescent intensity of [Eu(pic)₃(L2)] is about 2.6 times that of [Eu(pic)₃(L1)] in solid states. But in CHCl₃ solution, the fluorescent intensity of [Eu(pic)₃(L1)] is stronger slightly than [Eu(pic)₃(L2)].     

Acid–Basic Properties of Al(III), Ga(III), and In(III) Complexes with Octaphenyltetraazaporphine

Al(III), Ga(III), and In(III) complexes with octaphenyltetraazaporphine and halide axial ligands of the composition [(X)MTAP] (X = F, Cl, Br) and In(III) complexes with bidentate ligands of the composition [(Y)InTAP] (Y = nitrite (NO₂) and 2,3-naphthodiolate (NpO₂)) were synthesized. The acid–basic properties of the complexes were studied in the proton-donor media and the concentration stability constants of the acidic forms obtained at the first protonation stage were determined. The effect of the nature of a metal and extra ligand on the basic properties of meso-nitrogen atom in macrocyclic ligand was discussed.     

Crystal Structures of the Lanthanum(III), Europium(III), and Terbium(III) Cryptates of Tris(bipyridine) Macrobicyclic Ligands

The crystal structures of the La^III, Eu^III, and Tb^III complexes of macrobicyclic [bpy.bpy.bpy] ligands, [La³⁺ ? 1 ]3 Cl^? ( = 3- La), [Tb³⁺ ? 1 ]3 Cl^? ( = 3- Tb), and [Eu³⁺ ? 2 ]3 C1^? ( = 3- Eu), have been determined. They confirm the cryptate nature of these species, the cations being bound to the eight N-sites of the ligand. The macrobicycle presents two open faces, thus allowing additional coordination of two species, Cl^? ions or H₂O molecules, to the bound cations. These data provide structural support for the photophysical studies of the luminescent properties of the Eu^III and Tb^III cryptates, which indicated residual coordination of H₂O molecules.     

Hexa(isothiocyanato)chromates(III) of Some Yttrium Group Lanthanide(III) and Europium Complexes with Nicotinic Acid: Synthesis and Crystal Structures

Double ionic complexes [M(C₅H₅NCOO)₃(H₂O)₂][Cr(NCS)₆] · nH₂O, where M = Eu (I), n = 1.15; Dy (II), Er (III), n = 1.5; M = Yb (IV), n = 2, have been synthesized by the reaction between M(NO₃)₃, M = Eu, Dy, Er, Yb, K₃[Cr(NCS)₆], and nicotinic acid (C₅H₅NCOO) in an aqueous solution and studied by chemical analysis, IR spectroscopy, and X-ray diffraction. Crystals of complexes I–IV are monoclinic, space group P2₁/n, Z = 4; a = 9.5358(2) Å, b = 25.4871(5) Å, c = 15.4303(4) Å, β = 105.513(1)°, V = 3613.6(1) ų, ρ_calcd = 1.799 g/cm³ for I, a = 9.5901(5) Å, b = 25.8599(15) Å, c = 15.6316(9) Å, β = 106.829(2)°, V = 3710.6(4) ų, ρ_calcd = 1.782 g/cm³ for II, a = 9.5640(3) Å, b = 25.8936(11) Å, c = 15.6498(7) Å, β = 106.895(2)°, V = 3708.3(3) ų, ρ_calcd = 1.791 g/cm³ for III, and a = 9.5049(2) Å, b = 25.6378(4) Å, c = 15.5120(3) Å, β = 106.934(1)°, V = 3616.1(1) ų, ρ_calcd = 1.864 g/cm³ for IV.     

新型铕三元配合物的合成及光致和电致发光性能研究

利用氮杂苯并 [9,10 ]菲类中性配体 ,合成了两个新型铕三元配合物Eu(DBM) 3 L1和Eu(DBM) 3 L2 (DBM为二苯甲酰甲烷 ;L1,L2 为氮杂苯并 [9,10 ]菲类中性配体 ) ,以元素分析、红外光谱和紫外光谱对其进行了表征 .两种配合物在固体状态下的发射光谱都表现出较强的三价铕离子的特征发射 ,第二配体对中心离子具有较好的协同敏化发光作用 .以TPD和Gd(DBM) 3 bath (bath =4,7 二苯基 1,10 菲咯啉 )分别作空穴传输材料和电子传输材料 ,以发光配合物和TPD的共蒸镀掺杂作为发光层 ,制备了如下结构的三层器件ITO/TPD( 3 0nm) /Eu(DBM) 3 L1(L2 )∶TPD( 1∶2 ) ( 5 0nm) /Gd(DBM) 3 bath( 3 0nm) /Mg∶Ag ,并研究了器件的光电特性 .结果表明 :这两种配合物具有优良的成膜性和电子传输性 ,而氮杂苯并 [9,10 ]菲类中性配体对提高配合物的电子传输性起着至关重要的作用 .以Eu(DBM) 3 L1和Eu(DBM) 3 L2 作为发光材料制备的器件均具有较低的启亮电压 ( 3V) ,分别在 12V ,5 2mA·cm-2 和 13V ,42mA·cm-2 时获得最大亮度为 14 8cd·m-2 和 110cd·m-2 的纯正红色发光     

Organosilicon Amine Complexes of Cobalt(II), Cromium(III), and Neodymium(III): Synthesis and Properties

Organosilicon amine complexes [Co(NH₂R¹)₂Cl₂] (I), [Cr(NH₂R¹)₃Cl₃] (II), and [Nd(NH₂R¹)₃Cl₃] (III) [R¹ = CH₂CH₂CH₂Si(OEt)₃] were synthesized by reacting anhydrous cobalt, chromium, or neodymium chlorides with 3-aminopropyltriethoxysilane (NH₂R¹). Complexes I–III occur as colored viscous liquids that polymerize in air due to hydrolysis of triethoxy groups and condensation of the obtained silanol groups. Organosilicon films with a thickness of 10–200 m on glass and quartz substrates were obtained from liquid compositions containing complexes I–III, siloxanediols HO(SiMe₂O) _n H (n = 2–5), and alkoxysilanes NH₂R¹, MeSi(OMe)₃, and PhSi(OMe)₃ by solidification in air or vacuum. The obtained films were characterized by IR and electron spectroscopies, photoluminescence, transmission electron microscopy, and energy dispersion X-ray fluorescence analyses. IR and electron spectroscopies were used to study the structurization of the films and their behavior when heated to 100–300°C or exposed to gaseous O₂, NO, NH₃, or HCl. The film containing complex I was found to withstand heating in air to 250°C and to change its color in the atmosphere of NO, NH₃, and HCl. Complex I reversibly absorbs oxygen, and in the atmosphere of HCl, it converts into [NH₃R]₂[CoCl₄]. The Z-scanning method was used to uncover the cubic nonlinear-optical properties of the metal complexes.     

Stability constants and thermodynamic functions of Y(III), Rh(III), Sm(III), Gd(III) and Dy(III) with juglone (5-hydroxy-1,4-naphthoquinone)

This work considers how the ratio signal/noise and the introduction of a cut-off frequency affect the calculus of the thermogenesis. In particular, the validity of the experimental criterion used to calculate this frequency inside the deconvolutive calculus is studied. The deconvolutive efficiency of the universal transference function is also presented comparatively.     

New Bismuth(III), Lanthanum(III), Praseodymium (III), and Heterodinuclear Bi-La and Bi-Pr Complexes with Polyaminocarboxylate Ligands

New Bi(III), La(III) and Pr(III) complexes with a variety of high-denticity polyaminocarboxylic acids (H₄edta, H₅dtpa, H₆ttha, H₄Cydta, H₅hpdta, H₄egta) have been synthesized and characterized spectroscopically by FTIR. In the case of the decadentate ttha ligand, homodinuclear M₂(ttha) (M=Bi, La, Pr) and heterodinuclear MM′(ttha) complexes were isolated. Detailed investigations of their thermal degradation scheme were carried out in relationship with the possible use of these complexes as molecular precursors for the formation of mixed Bi-La and Bi-Pr oxides in which the crystal structure of the fluorite-like δ-Bi₂O₃ phase can be stabilized at room temperature. Decomposition proceeds in three successive stages, consisting of dehydration, ligand pyrolysis leading to monoxo-, dioxo- or simple carbonates, depending on the metal nature, and finally decarbonatation producing the corresponding oxide: α-Bi₂O₃, La₂O₃, Pr₆O₁₁, BiLaO₃ or BiPrO₃.     

Spectrophotometric Study of Mithramycin Complexes with Cu(II), Fe(III) and Tb(III)

Abstract

The coordination of the anticancer drug mithramycin to Tb(III), Fe(III) and Cu(II) was studied in aqueous solution using absorption measurements. The stability constants were calculated from equilibrium competition experiments by means of the SQUAD program. For both first ions, the competitor was oxalic acid and for the latter the competitor was the Cu(II) ions. Cu(II) at pH 7.5, Fe(III) at pH 3.5 and Tb(III) at pH 5.5 formed respectively 1:2, 1:3 and 1:4 metal-to-ligand species.     

Sc(III), Eu(III), and Gd(III) Complexes with Macrocyclic Cavitand Cucurbit[6]uril: Synthesis and Crystal Structures

Slow evaporation of solutions of Sc and Eu nitrates with macrocyclic cavitand cucurbit[6]uril gives crystals of isostructural complexes [Sc(NO₃)(H₂O)₄(C₃₆H₃₆N₂₄O₁₂)](NO₃)₂ ? 8.5H₂O (space group Pna2₁, a = 32.0065(18) Å, b = 14.7904(8) Å, c = 11.5774(6) Å, V = 5480.6(5) ų, Z = 4) and [Eu(NO₃)(H₂O)₄(C₃₆H₃₆N₂₄O₁₂)](NO₃)₂ ? 6.75H₂O (space group Pna2₁, a = 31.9525(17) Å, b = 14.7203(8) Å, c = 11.8592(6) Å, V = 5578.0(5) ų, Z = 4). The metal to ligand ratio in these complexes is 1 : 1; the complexes are obtained at 0.025–0.1 mol/l concentrations of the metals in solutions. With higher lanthanide concentrations (0.7–1 mol/l), the 2 : 1 complex with cucurbit[6]uril is formed of the composition [{ Gd(NO₃)(H₂O)₅}₂(C₃₆H₃₆N₂₄O₁₂)](NO₃)₄ ? 6.5H₂O (space group \(P\bar 1\), a = 13.3972(6) Å, b = 14.4994(5) Å, c = 18.3290(8) Å, α = 73.5610(10)°, β = 87.2590(10)°, γ = 87.5540(10)°, V = 3409.4(2) ų, Z = 2) and isotypical complex [{Gd(NO₃)(H₂O)₅}₂{(C₅H₅N) ? (C₃₆H₃₆N₂₄O₁₂)}](NO₃)₄ ? 8H₂O with a pyridine molecule inside the cucurbit[6]uril cavity (space group P2₁/n, a = 14.8263(6) Å, b = 13.3688(7) Å, c = 18.5970(9) Å, β = 107.5860(10)°, V = 3513.8(3) ų, Z = 2). According to X-ray diffraction data, the metal atoms of the title complexes coordinate the O atoms in portals of cucurbit[6]uril molecules.     

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.