I. V. Taidakov

Synthesis and luminescent properties of neutral Eu(III) and Gd(III) complexes with 1-(1,5-dimethyl-1h-pyrazol-4-yl)-4,4,4-trifluoro-1,3-butanedione and 4,4,5,5,6,6,6-heptafluoro-1-(1-methyl-1H-pyrazol-4-yl)-1,3-hexanedione

Neutral [EuL3Phen] complexes were synthesized by the reaction of EuCl3 with heterocyclic diketones-1-(1,5-dimethyl-1H-pyrazol-4-yl)-4,4,4-trifluoro-1,3-butanedione and 4,4,5,5,6,6,6-heptafluoro-1-(1-methyl-1H-pyrazol-4-yl)-1,3-hexanedione—and 1,10-phenanthroline (Phen) in an aqueous alcohol solution in the presence of NaOH. The reaction of GdCl3 with the same diketones under analogous conditions, but without adding 1,10-phenanthroline, yielded [GdL3(H2O)2] complexes. The composition of the complexes was determined by elemental analysis, and their optical and luminescent properties were examined.

An efficient route for design of luminescent composite materials based on polyethylene containing europium dibenzoylmethanate

Luminescent composite materials based on linear polyethylene doped by a well dispersed tetrakis dibenzoylmethanate europium complex have been developed. The anion of the latter serves as an efficient light harvesting antenna and possesses the desired photophysical properties. The targeted modification of the Eu complex, namely introduction of a long hydrocarbon chain into the tetraalkylammonium cation [RNEt3]+, has ensured the compatibility of the complex with the polyethylene matrix. The [RNEt3]+ cation has been obtained by using long-chained 1-iodoalkanes synthesized via the Nd-catalyzed ethylene oligomerization process. The photophysical properties and the homogeneity of the obtained composites have been controlled by optical spectroscopy, luminescence intensity mapping as well as scanning electron microscopy.

Neodymium(III) tris(1,3-bis(1,3-dimethyl-1H-pyrazol-4-yl)propane-1,3-dionato)(1,10-phenanthroline): Synthesis and photophysical properties

The reaction of NdCl3 with 1,3-bis(1,3-dimethyl-1H-pyrazol-4-yl)propane-1,3-dione (HL) and 1,10-phenanthroline (Phen) in the presence of a base afforded complex [Nd(L)3Phen] (I). Unstable solvate I · 2CH2Cl2 was obtained from a solution of the complex in dichloromethane, and its structure was determined by X-ray diffraction analysis. The photophysical properties of the complex were studied. Possible routes for the energy transfer in the course of photoluminescence were proposed.

Yttrium(III) and lanthanum(III) tris(1,3-bis(1,3-dimethyl-1H-pyrazol-4-yl)propane-1,3-dionato)(1,10-phenanthroline): Synthesis and study by mass spectrometry, X-ray diffraction analysis, and 89Y and 139La NMR spectroscopy

The reactions of LaCl3 and YCl3 with 1,3-bis(1,3-dimethyl-1H-pyrazol-4-yl)propane-1,3-dione (HL) and 1,10-phenanthroline (Phen) in the presence of a base afford complexes [La(L)3(Phen)] (I) and [Y(L)3(Phen)] (II). Unstable solvates I · iso-PrOH (III) and II · iso-PrOH (IV) are obtained from solutions of the complexes in 2-propanol, and their structures are determined by X-ray diffraction analysis (CIF files CCDC 1026802 (III) and 1026808 (IV)). The compositions of the complexes are additionally studied by 1H, 13C, 89Y, and 139La NMR methods. Fragmentation is studied by laser desorption/ionization (LDI) and electrospray ionization (ESI) mass spectrometry.

Synthesis and luminescence properties of neutral Tm(III), Dy(III), and Gd(III) complexes with 1,3-bis(1,3-dimethyl-1H-pyrazol-4-yl)-1,3-propanedione and 1,10-phenanthroline

Neutral complexes of composition [LnL3Phen], where Ln = Tm, Dy, and Gd, were synthesized by the reaction of LnCl3 with heterocyclic diketone 1,3-bis(1,3-dimethyl-1H-pyrazol-4-yl)-1,3-propanedione (HL, 1) and 1,10-phenanthroline in an aqueous alcohol solution in the presence of NaOH. The composition of the complexes was proved by elemental analysis. Their optical and luminescence properties were studied.

Spontaneous Association of the Terbium Cyclopentadienyl Complexes under Controlled Hydrolysis

Controlled hydrolysis of the terbium cyclopentadienyl complexes results in the formation of the heteroligand tetranuclear terbium complex [{Tb(η5-C5H5)}3{Tb(THF)3}(μ3-Cl)(μ2-Cl)6(μ4-O)] (I), the recrystallization of which from tetrahydrofuran (THF) gives solvatomorph I · 0.5THF (Ia). According to the X-ray structure analysis data (CIF files CCDC 1569329 (I) and 1569330 (Ia)), the complexes are tetrahedral with the μ4-bridging O2– anion at the center of the tetrahedron. The cyclopentadienyl ligand in complex I is shown to act as an “antenna” providing luminescence of the complex.

Lanthanide(III) (Eu, Gd, Tb, Dy) Complexes Derived from 4-(Pyridin-2-yl)methyleneamino-1,2,4-triazole: Crystal Structure, Magnetic Properties, and Photoluminescence

The reaction of lanthanide(III) nitrates with 4-(pyridin-2-yl)methyleneamino-1,2,4-triazole (L) was studied. The compounds [Ln(NO3 )3 (H2 O)3 ]⋅2 L, in which Ln=Eu (1), Gd (2), Tb (3), or Dy (4), obtained in a mixture of MeCN/EtOH have the same structure, as shown by XRD. In the crystals of these compounds, the mononuclear complex units [Ln(NO3 )3 (H2 O)3 ] are linked to L molecules through intermolecular hydrogen-bonding interactions to form a 2D polymeric supramolecular architecture. An investigation into the optical characteristics of the Eu3+ -, Tb3+ -, and Dy3+ -containing compounds (1, 3, and 4) showed that these complexes displayed metal-centered luminescence. According to magnetic measurements, compound 4 exhibits single-ion magnet behavior, with ΔEeff /kB =86 K in a field of 1500 Oe.

Synthesis, crystal structure, and spectral properties of tris-[4,4,5,5,6,6,6-heptafluoro-1-(1-methyl-1H-pyrazol-4-yl)-1,3-hexanedionato](diethanolo)gadolinium(III)

Reaction of Gd(NO3)3 · 6H2O with 4,4,5,5,6,6,6-heptafluoro-1-(1-methyl-1H-pyrazol-4-yl)-1,3-hexanedione in aqueous ethanol solution in the presence of NaOH at ambient temperature was found to give rise to complex GdL3[O(H)Et]2 in 64% yield. The prepared complex was characterized by X-ray crystallography, its luminescent properties were studied, and the energy of ligand triplet level was determined experimentally.

Synthesis and unusual crystal structure of the Eu(III) complex with 1-(1,5-dimethyl-1H-pyrazol-4-yl)-4,4,4-trifluorobutane-1,3-dione

The reaction of Eu(NO3)3 · 6H2O with 1-(1,5-dimethyl-1H-pyrazol-4-yl)-4,4,4-trifluorobutane-1,3-dione (HL) in the presence of NaOH in aqueous ethanol gave neutral complex [EuL3(H2O)] (I). The unstable adduct [EuL3(H2O)] · 1.3MeCN (Ia) was obtained from an acetonitrile solution and studied by X-ray diffraction. The crystals of Ia at 100 K are monoclinic, a = 17.551(3) Å, b = 11.532(2) Å, c = 20.371(3) Å, β = 110.886(3)°, V = 3852(1) Å3, space group P21/c, Z = 4, R = 0.0505. The molecules are connected into chains by strong interactions between the europium atom of one molecule and the pyrazole N(2) atom of another molecule and additionally stabilized by strong hydrogen bonds O(1w)-H(1w1)…N(4)*. The chains are combined into layers by the hydrogen bonds (1w)-H(2w1)…N(2)*.

Cesium tetrakis(1-(1,5-dimethyl-1H-pyrazol-4-yl)-4,4,4-trifluorobutane-1,3-diono)europiate(III): Synthesis, crystal structure, and luminescence properties

Anionic complex Cs+[EuL4]− (I) is synthesized by the reaction of Eu(NO3)3 · 6H2O with 1-(1,5-dimethyl-1H-pyrazol-4-yl)-4,4,4-trifluorobutane-1,3-dione (HL) and CsOH in an aqueous-alcohol medium. Unstable adduct Cs+[EuL4]− · 2CH2Cl2 (Ia) is obtained from a solution in CH2Cl2. The structure of complex Ia is determined by X-ray diffraction analysis. The crystals of complex Ia at 100 K are monoclinic, a = 10.8435(5), b = 20.1353(9), c = 23.355(1) Å, β = 92.548(1)°, V = 5094.3(4) Å3, space group P21/n, Z = 4, and R = 0.0294. The coordination number of the Cs+ ion is 9. The Cs+ ion forms shortened (up to 3.3 Å) contacts with the O, N, and F atoms of four diketonate fragments joining the molecules into a three-dimensional structure.