Synthesis, crystal structures and spectroscopic properties of pure YSb2O4Br and YSb2O4Cl as well as Eu3+- and Tb3+-doped samples

The quaternary halide-containing yttrium(iii) oxidoantimonates(iii) YSb(2)O(4)Cl and YSb(2)O(4)Br were synthesised through solid-state reactions from the binary components (Y(2)O(3), Sb(2)O(3) and YX(3), X = Cl and Br) at 750 °C in evacuated fused silica ampoules with eutectic mixtures of NaX and CsX (X = Cl and Br) as fluxing agents. YSb(2)O(4)Cl crystallizes tetragonally in the non-centrosymmetric space group P42(1)2 with unit-cell parameters of a = 773.56(4) pm and c = 878.91(6) pm, whereas YSb(2)O(4)Br is monoclinic (space group: P2(1)/c) with a = 896.54(6) pm, b = 780.23(5) pm, c = 779.61(5) pm and β = 91.398(3)°, both for Z = 4. The two new YSb(2)O(4)X compounds contain [YO(8)](13−) polyhedra, which are connected via four common edges to form [Image: see text] layers (d(Y(3+)–O(2−)) = 225–254 pm) without any Y(3+)⋯X(−) bonds (d(Y(3+)⋯X(−)) > 400 pm). Moreover, all oxygen atoms belong to ψ(1)-tetrahedral [SbO(3)](3−) units, which are either connected to four-membered rings [Sb(4)O(8)](4−) in the chloride (Y(2)[Sb(4)O(8)]Cl(2) for Z = 2) or endless chains in the bromide (Y(1/2)(SbO(2))Br(1/2) for Z = 8) by common vertices. With distances of 307 pm in YSb(2)O(4)Cl and 326 pm in YSb(2)O(4)Br there are not even substantial bonding Sb(3+)⋯X(−) (X = Cl and Br) interactions at work. Luminescence spectroscopy on samples doped with trivalent europium and terbium showed an energy transfer from the oxidoantimonate(iii) moieties as the sensitizer in the host structure onto the lanthanoid activators

The Triclinic Lanthanoid(III) Halide Oxidoarsenates(III) Sm3Cl2[As2O5][AsO3] and Tm3Br2[As2O5][AsO3]

Pale yellow single crystals of the composition Ln(3)X(2)[As2O5][AsO3] (Ln = Tm for X = Br and Ln = Sm for X = Cl) were obtained via solid-state reactions in the systems Ln(2)O(3)/As2O3 from sealed silica ampoules using different halides as fluxing agents. Sm3Cl2[As2O5][AsO3] and Tm3Br2[As2O5][AsO3] crystallize isotypically in the triclinic space group P (1) over bar with Z = 2 and cell parameters of a = 543.51(4) pm, b = 837.24(6) pm, c = 1113.45(8) pm, a = 90.084(2)degrees, beta = 94.532(2)degrees, gamma = 90.487(2)degrees for the samarium and a = 534.96(4) pm, b = 869.26(6) pm, c = 1081.84(8) pm, a = 90.723(2)degrees, beta = 94.792(2)degrees gamma = 90.119(2)degrees for the thulium compound. The isotypic crystal structure of both representatives exhibits three crystallographically different Ln(3+) cations, each with a coordination number of eight. (Ln1)(3+) and (Ln2)(3+) are only coordinated by three oxygen atoms, whereas (Ln3)(3+) shows additional contacts to halide anions in forming square [LnO(4)X(4)](9-) antiprisms. All As3+ cations are surrounded by three oxygen atoms in the shape of isolated [AsO3](3-) psi(1)-tetrahedra. They occur either isolated or condensed as pyroanionic [As2O5](4-) units with a bridging oxygen atom. In both anions, non-binding lone-pair electrons are present at the As3+ cations with a pronounced stereochemically active function

The monoclinic rare earth metal(III) chloride oxidoarsenates(III) with the composition RE5Cl3 [AsO3](4) (RE = La-Nd, Sm)

The rare earth metal(III) chloride oxidoarsenates(III) with the composition RE5Cl3[AsO3](4) (RE= La-Nd, Sm) could be synthesized via solid-state methods through the reaction of arsenic sesquioxide (As2O3) with the corresponding rare earth metal compounds (La2O3, CeO2 + metallic Ce, Pr6O11, Nd2O3 or metallic Sm) using several chloride-containing fluxing agents in evacuated silica glass ampoules. The compounds build up non-isotypic crystal structures in the monoclinic space groups C2/c for RE= La-Pr, and P2/c for RE= Nd and Sm. All rare earth metal(III) cations exhibit coordination numbers of eight. While (RE1)(3+) and (RE2)(3+) are only surrounded by oxygen atoms in the form of distorted square antiprisms or prisms, (RE3)(3+) is coordinated square antiprismatically by four oxygen atoms and four chloride anions. Although the coordination polyhedra in both structures differ only marginally, their connection patterns show more pronounced differences. This regards especially the (RE)(3+) cations and results from different site symmetries of the (Cl1)(-) anions. All As3+ lone-pair cations are coordinated by three oxygen atoms to form psi(1)-tetrahedral [AsO3](3-) complex anions with their non-binding (lone) electron pairs pointing into empty channels along [010]

Functionalized branched EDOT-terthiophene copolymer films by electropolymerization and post-polymerization “click”-reactions

The electrocopolymerization of 3,4-ethylenedioxythiophene (EDOT) with the branched thiophene building block 2,2′:3′,2″-terthiophene (3T) is presented as a versatile route to functional polymer films. Comparisons to blend systems of the respective homopolymers PEDOT and P3T by in situ spectroelectrochemistry and Raman spectroscopy prove the successful copolymer formation and the access to tailored redox properties and energy levels. The use of EDOT-N3 as co-monomer furthermore allows modifications of the films by polymer analogous reactions. Here, we exemplarily describe the post-functionalization with ionic moieties by 1,3-dipolar cycloaddition (“click”-chemistry) which allows to tune the surface polarity of the copolymer films from water contact angles of 140° down to 40°