E. M. Uskov

Cluster compounds [Ca(DMF)6][Mo6Cl14] and [{Ca(OPPh3)4}{Mo6Cl14}]∞: Synthesis, crystal structure, and properties

The [Ca(DMF)6][Mo6Cl14] complex (I) was synthesized by reacting octahedral cluster Mo complex (H3O)2Mo6Cl14·6H2O with the Ca2+ cation in DMF. Analogous reaction carried out in the presence of triphenylphosphine oxide Ph3PO in acetonitrile resulted in [{Ca(OPPh3)4}{Mo6Cl14}] (II). According to X-ray diffraction data, complex I has ionic structure, while the structure of complex II consists of infinite linear chains of the cluster anionic complexes {Mo6Cl14}2− bonded to the cationic Ca complexes {Ca(OPPH3)4}2+. Both complexes exhibit intensive luminescence in red and near-IR regions of the spectrum.

Synthesis and photoluminescence of the chiral compounds [ZnLCl2] · EtOH and ZnLCl2, where L is the (+)-3-Carene derivative containing pyrazoline and quinoline fragments: crystal structure of [ZnLCl2] · EtOH

The following chiral compounds were synthesized: [ZnLCl2] · EtOH (I) and ZnLCl2 (II), where L is the pyrazolin-5-ol derivative obtained from terpene (+)-3-carene. According to the X-ray diffraction data, the crystal structure of compound I is built of acentric molecules of the mononuclear ZnLCl2 complex and EtOH molecules. In molecules of the complex, the Zn2+ ion is coordinated by two N atoms of the bidentate chelating ligand L and two Cl atoms at the vertices of the distorted tetrahedron. The intermolecular contacts and the hydrogen bonds Cl(1)…H-O(1) between the adjacent ZnLCl2 molecules result in the formation of chains parallel to the y axis. The reactant L and solvate I possess weak photoluminescence in the visible spectral range. Complex II exhibits more intense photoluminescence at λmax = 416 and 517 nm.

Synthesis, structures, and photoluminescence of heteroligand complexes Ln(L)(iso-Bu2PS2)2(NO3) (Ln = Sm, Tb, Dy; L = Phen, 2,2′-Bipy)

Heteroligand complexes Ln(L)(iso-Bu2PS2)2(NO3) (Ln = Sm, Tb, Dy; L = Phen, 2,2′-Bipy) (I–VI) are synthesized. The structure of Dy(Phen)(iso-Bu2PS2)2(NO3) (III) is determined from the data of X-ray structure analysis. The crystal structure of complex III is based on discrete mononuclear molecules in which the Dy atom has distorted dodecahedral coordination (polyhedron N2O2S4). The ligands Phen, iso-Bu2PS2− and NO3− are bidentate-cyclic. According to the X-ray diffraction analysis data, complexes I and II are isostructural to compound III. Complexes I–VI have photoluminescence in the visible spectral range. The photoluminescence spectra of solid samples of compounds I–VI exhibit bands corresponding to the radiative electron transitions of the Sm3+, Tb3+, and Dy3+ ions. Among the studied compounds I–VI, the Tb(III) complexes are characterized by the most intense photoluminescence.

Luminescence properties of complexes Ln(Phen)(C6F5COO)3 (Ln = Tb, Eu) and Ln(C6F5COO)3 · nH2O (Ln = Tb, n = 2; Ln = Eu, n = 1). Structures of the [Tb2(H2O)8(C6F5COO)6] complex and its isomer in the supramolecular compound [Tb2(H2O)8(C6F5COO)6] · 2C6F5COOH

Complexes Ln(Phen)(C6F5COO)3 (Ln = Tb, Eu; Phen = 1,10-phenanthroline) (I, II) are synthesized. At 300 K these complexes and compounds Ln(C6F5COO)3 · nH2O (Ln = Tb, n = 2; Ln = Eu, n = 1) (III, VI) possess photoluminescence (bright in the case of I and II). In the spectrum of compound I the line at 545 nm (transition 5D4 → 7F5) is most intense, whereas in the spectrum of compound II the most intense is the line at 613 nm (transition 5D0 → 7F2). The replacement of Phen by water decreases the luminescence intensity. The compound [Tb2(H2O)8(C6F5COO)6] · 2C6F5COOH (IV) is synthesized. According to the X-ray diffraction data, in structure IV the molecules of the binuclear Tb(III) complex with the C6F5COOH molecules form a supramolecular ensemble due to hydrogen bonding. The C6F5COO− ligands perform the monodentate and bidentate bridging function, resulting in the opening of the eight-membered cycle Tb2C2O4. The TbO8 polyhedron is a distored tetragonal antiprism. The crystals of the binuclear complex [Tb2(H2O)8(C6F5COO)6] (V) are obtained in which the C6F5COO− ligands are monodentate and tridentate bridging cyclic, which results in the closure of two four-membered cycles TbO2C and one four-membered cycle Tb2O2. The TbO9 polyhedron is a distorted monocapped tetragonal antiprism.

Synthesis and photoluminescence of the heteroligand Sm(III) complexes containing nitrogen heterocycles (Phen, 2,2′-Bipy) and anions C4H8NCS2−, iso-Bu2PS2−, (iso-PrO)2PS2−, and NO3−. Crystal structure of Sm(2,2′-Bipy)2(NO3)3

The photoluminescence spectra of the known complexes, Sm(L)2(NO3)3 (I, II), Sm(L)(iso-Bu2PS2)3 (III, IV), Sm(L)(iso-Bu2PS2)2(NO3) (V, VI) (L = Phen, 2,2′-Bipy), and Sm(Phen)(C4H8NCS2)3 (VIII), and new compounds, Sm(Phen)((iso-PrO)2PS2)3 (VII), Sm(2,2′-Bipy)(C4H8NCS2)3 · 0.5CH2Cl2 (IX), are obtained and interpreted. Using the X-ray structure analysis data, the crystal structure of the [Sm(2,2′-Bipy)2(NO3)3] complex (II) is determined. Structure II consists of discrete mononuclear molecules having a ten-vertex coordination polyhedron N4O6. The ligands 2,2′-Bipy and NO3− are bidentate-cyclic. The influence of the composition of the complexes on the photoluminescence (PL) intensity in the series I–VI is considered. The dependence of the intensity of the band with λmax = 647 nm in the PL spectra of complexes III, VII, and VIII on the type of the sulfur-containing ligand in their composition is established. The band intensity changes in the series VIII > III > VII.

Syntheses and structures of p-HOOCC6F4COOH · H2O (H2L · H2O) and luminescent coordination polymers [Tb2(H2O)4(L)3 · 2H2O]n and Tb2(Phen)2(L)3 · 2H2O

Compounds p-HOOCC6F4COOH · H2O (H2L · H2O), [Tb2(H2O)4(L)3 · 2H2O]n (I), and Tb2(Phen)2(L)3 · 2H2O (II) are synthesized. According to the X-ray structure analysis data, the crystal structure of H2L · H2O is built of centrosymmetric molecules H2L and molecules of water of crystallization. The crystal structure of compound I is built of layers of coordination 2D polymer [Tb2(H2O)4(L)3]n and molecules of water of crystallization. The ligands are the L2− anions performing both the tetradentate bridging and pentadentate bridging-chelating functions. The coordination polyhedron TbO9 is a distorted three-capped trigonal prism. Acid H2L manifests photoluminescence in the UV region (λmax = 368 nm). Compounds I and II have the green luminescence characteristic of the Tb3+ ions, and the band with λmax = 545 nm (transition 5D4→ 7F5) is maximum in intensity. The photoluminescence intensity of compound II is higher than that for compound I.

Crystal structure of solvate [Cd2L2Cl4]·CH2Cl2 (L = pyrazolylquinoline, the derivative of monoterpenoid (+)-3-carene) and photoluminescence of chiral complex CdLCl2

Using the single crystal X-ray diffraction data (150 K, Bruker X8 Apex CCD autodiffractometer, MoKα radiation), the crystal structure of the [Cd2L2Cl4]·CH2Cl2 (L = pyrazolylquinoline, the derivative of monoterpenoid (+)-3-carene) compound is determined. Crystals are monoclinic, unit cell parameters are: a = 10.7005(4) Å, b = 16.8491(4) Å, c = 11.9658(4) Å, β = 93.308(1)°, P21 space group. The structure is formed from discrete acentric molecules of a binuclear [Cd2L2Cl4] complex and uncoordinated CH2Cl2 molecules. The Cd2+ ions coordinate N atoms of bidentate chelating ligands L, which leads to the closure of two five-membered chelate CdN3C rings. The coordination sphere of Cd atoms also includes three Cl atoms (two bridging and one terminal), consequently, two CdCl3N2 coordination sites and a Cd2Cl2 metal ring are formed. The Cl3N2 polyhedra have the form of distorted tetragonal pyramids. The CH2Cl2 molecules located in the channels formed by the complexes are linked with them by weak H-bonds. The excitation spectra of L and the CdLCl2 compound contain bands with λmax of 352 nm and 360 nm respectively. At 300 K and λexcit 350 nm, in the photoluminescence spectrum of L a rather intense broad split band with λmax 372 nm and 386 nm is observed. The photoluminescence spectrum of the CdLCl2 compound contains a broad band with λmax 418 nm. The photoluminescence intensity of this compound is significantly lower than that of L.

Synthesis of heteroligand complex Nd(Phen){(iso-C4H9)2PS2}2(NO3). Crystal structure of [Nd(Phen){(iso-C4H9)2PS2}3] and luminescent properties of these compounds

AbstractThe heteroligand complex Nd(Phen){(iso-C4H9)2PS2}2(NO3) (I) was synthesized and its IR spectrum was analyzed. The anions (iso-C4H9)2PS2/− and N3/− act as bidentate cyclic ligands. The single crystals of [Nd(Phen){iso-C4H9)2PS2}3] (II) were obtained on evaporation of a solution of complex I in a mixture CH2Cl2-hexane and were studied by X-ray diffraction. Crystals II are triclinic: a = 10.5509(5); b = 14.7432(8), c = 16.8503(10) Å; α = 102.882(2)°, β = 97.211(2)°, γ= 108.087(2)°, V = 2374(2) Å3, Z = 2, ρ(calcd.) = 1.332 g/cm3, space group

Synthesis and photoluminescence of Eu(III) and Tb(III) complex compounds containing anions of 4-CF3C6F4COOH and 4-(CF3)2CFC6F4COOH acids

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