18-Crown-6

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Claus Feldmann - One of the best experts on this subject based on the ideXlab platform.

  • Bromine-rich Zinc Bromides: Zn6Br12(18-Crown-6)2×(Br2)5, Zn4Br8(18-Crown-6)2×(Br2)3, and Zn6Br12(18-Crown-6)2×(Br2)2
    Inorganic chemistry, 2016
    Co-Authors: David Hausmann, Claus Feldmann
    Abstract:

    The bromine-rich zinc bromides Zn6Br12(18-Crown-6)2×(Br2)5 (1), Zn4Br8(18-Crown-6)2×(Br2)3 (2), and Zn6Br12(18-Crown-6)2×(Br2)2 (3) are prepared by reaction of ZnBr2, 18-Crown-6, and elemental bromine in the ionic liquid [MeBu3N][N(Tf)2] (N(Tf)2 = bis(trifluoromethylsulfonyl)amide). Zn6Br12(18-Crown-6)2×(Br2)5 (1) is formed instantaneously by the reaction. Even at room temperature, compound 1 releases bromine, which was confirmed by thermogravimetry (TG) and mass spectrometry (MS). The release of Br2 can also be directly followed by the color and density of the title compounds. With controlled conditions (2 weeks, 25 °C, absence of excess Br2) Zn6Br12(18-Crown-6)2×(Br2)5 (1) slowly releases bromine with conconcurrent generation of Zn4Br8(18-Crown-6)2×(Br2)3 (2) (in ionic liquid) and Zn6Br12(18-Crown-6)2×(Br2)2 (3) (in inert oil). All bromine-rich zinc bromides contain voluminous uncharged (e.g., Zn3Br6(18-Crown-6), Zn2Br4(18-Crown-6)) or ionic (e.g., [Zn2Br3(18-Crown-6)]+, [(Zn2Br6)×(Br2)2]2–) building un...

  • [Pb2I3(18-Crown-6)2][SnI5] and CdI2(18-Crown-6) ∙ 2I2: Two Layered Iodine Networks with Crown-ether Coordinated Pb2+ and Cd2+
    Journal of Inorganic and General Chemistry Zeitschrift für anorganische und allgemeine Chemie, 2010
    Co-Authors: Michael Wolff, Claus Feldmann
    Abstract:

    [Pb2I3(18-Crown-6)2][SnI5] (1) and CdI2(18-Crown-6) ∙ 2I2 (2) were prepared by reaction of PbI2, SnI4 and 18-Crown-6 as well as CdI2, I2 and 18-Crown-6. All reactions were performed in the ionic liquid [NMe(n-Bu)3][N(Tf)2], which serves as polar but aprotic liquid-phase providing a fast diffusion of the reactants at moderate temperatures (100 °C). 1 exhibits V-shaped [Pb2I3(18-Crown-6)2]+ cations and trigonal-bipyramidal [SnI5]– anions. In CdI2(18-Crown-6) ∙ 2I2 (2), the building unit CdI2(18-Crown-6) formally contains linear CdI2 molecules that are interlinked by molecular iodine via long-ranging I–I contacts.

  • [Pb2I3(18‐crown‐6)2][SnI5] and CdI2(18‐crown‐6)·2I2: Two Layered Iodine Networks with Crown‐ether Coordinated Pb2+ and Cd2+
    Zeitschrift für anorganische und allgemeine Chemie, 2010
    Co-Authors: Michael W. Wolff, Claus Feldmann
    Abstract:

    [Pb2I3(18-Crown-6)2][SnI5] (1) and CdI2(18-Crown-6)·2I2 (2) were prepared by reaction of PbI2, SnI4 and 18-Crown-6 as well as CdI2, I2 and 18-Crown-6. All reactions were performed in the ionic liquid [NMe(nBu)3][N(Tf)2], which serves as polar but aprotic liquid-phase providing a fast diffusion of the reactants at moderate temperatures ( ≤ 100 °C). 1 exhibits V-shaped [Pb2I3(18-Crown-6)2]+ cations and trigonal-bipyramidal [SnI5]– anions. In CdI2(18-Crown-6)·2I2 (2), the building unit CdI2(18-Crown-6) formally contains linear CdI2 molecules that are interlinked by molecular iodine via long-ranging I–I contacts.

Jack Passmore - One of the best experts on this subject based on the ideXlab platform.

  • 18-Crown-6 and Titanium Tetrafluoride − Preparation of the TiIV Fluoride Crown Ether Complexes (TiF4)2(18-Crown-6) and the Stabilization of cis-TiF4(H2O)2 in [{cis-TiF4(H2O)2}2(18-Crown-6)]
    European Journal of Inorganic Chemistry, 2004
    Co-Authors: T. Stanley Cameron, Andreas Decken, Evgeny G. Ilyin, Grigory B. Nikiforov, Jack Passmore
    Abstract:

    Reaction of TiF4 and 18-Crown-6 in MeCN affords the molecular complex [(cis-TiF4)2(18-Crown-6)] (1) only. Water and THF displace the 18-Crown-6 in the tetrafluoro complex 1, with the formation of cis-TiF4L2. The complex cis-TiF4(H2O)2 and 18-Crown-6 form [{cis-TiF4(H2O)2}2(18-Crown-6)] (2), in which cis-TiF4(H2O)2 and 18-Crown-6 are connected by hydrogen bonding through the protons of coordinated H2O in TiF4(H2O)2 and the oxygen atoms of the crown ether. Complexes 1 and 2 were characterized by X-ray single crystal analysis, elemental analysis, IR, NMR and Mass spectroscopy. The relative basicities of the 18-Crown-6 and the molecular donor ligands MeCN, THF, H2O toward TiIV fluoride were established by NMR spectroscopic investigations of the substitution reactions. 18-Crown-6 is slightly more basic than MeCN, similar to that of Et2O, and less basic than THF and H2O. (© Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2004)

A. N. Chekhlov - One of the best experts on this subject based on the ideXlab platform.

  • (18-Crown-6)potassium 0.84(diiodobromide) 0.16(dibromoiodide) and diaqua(18-Crown-6)chlororubidium: Syntheses and crystal structures
    Russian Journal of Inorganic Chemistry, 2009
    Co-Authors: A. N. Chekhlov
    Abstract:

    New host-guest compounds are synthesized and studied by X-ray diffraction analysis: (18-Crown-6) potassium 0.84(diiodobromide) 0.16(dibromoiodide), [K(18-Crown-6)]+ · (Br1.16I1.84)−, (I) and diaqua (18-Crown-6)chlororubidium, [RbCl(18-Crown-6)(H2O)2], (II). The crystals of compound I are monoclinic (space group P21/n, a = 9.157 A, b = 8.589 A, c = 14.072 A, β = 102.27°, Z = 2). The structure of compound II is orthorhombic (space group Pnma, a = 9.813 A, b = 15.231 A, c = 12.629 A, Z = 4). The structures are solved by a direct method and refined by the full-matrix anisotropic least squares to R = 0.062 (I) and 0.079 (II) for 3149 (I) and 2840 (II) independent reflections (CAD-4 automated diffractometer, λMoKα radiation). The crystal structures of compounds I and II are different: compound I is built of infinite chains of the alternating cations [K(18-Crown-6)]+ and mixed halide anions linked by weak coordination bonds K-Br or K-I, whereas individual molecules [RbCl(18-Crown-6)(H2O)2] form structure II.

  • Diaquabromo(18-Crown-6)rubidium and triaqua(18-Crown-6)barium dibromide monohydrate: Synthesis and crystal structures
    Russian Journal of Inorganic Chemistry, 2008
    Co-Authors: A. N. Chekhlov
    Abstract:

    Two complexes are synthesized: diaquabromo(18-Crown-6)rubidium [RbBr(18-Crown-6)(H2O)2] (I) and triaqua(18-Crown-6)barium dibromide monohydrate [Ba(18-Crown-6)(H2O)3]2+ 2Br− · H2O (II). The orthorhombic structure of compound I (space group Pnma, a = 10.124 A, b = 15.205 A, c = 12.544 A, Z = 4) and the monoclinic structure of compound II (space group C 2/c, a = 17.910 A, b = 10.315 A, c = 14.879 A, β = 123.23°, Z = 4) are determined by a direct method and refined by the full-matrix least-squares method in the anisotropic approximation to R = 0.063 (I) and 0.042 (II) for all 2293 (I) and 3363 (II) independent measured reflections (CAD-4 automated diffractometer, λMoKα). The complex molecule [RbBr(18-Crown-6)(H2O)2] in compound I and the randomly disordered cation [Ba(18-Crown-6)(H2O)3]2+ in compound II are of the host-guest type: their Rb+ or Ba2+ cation (its coordination number is nine) is located in the cavity of the 18-Crown-6 ligand and coordinated by all six O atoms. In structure I, the coordination polyhedron of Rb+ is a distorted hexagonal pyramid with a triple apex at the Br− ligand and two O atoms of the water molecules. In structure II, the Ba2+ polyhedron is a distorted hexagonal bipyramid with one apex at the O atom of the water molecule and the other split apex at two O atoms of water molecules.

  • Synthesis and crystal structure of hexakis(isothiocyanato)erbium(III) thiocyanate bis(18-Crown-6)dipotassium bis[(18-Crown-6)ethanolpotassium]
    Russian Journal of Coordination Chemistry, 2008
    Co-Authors: A. N. Chekhlov
    Abstract:

    A new complex compound, [K2(18-Crown-6)2[K(18-Crown-6)(EtOH)]2[Er(NCS)6](SCN) (I), was synthesized and its crystal structure was studied by X-ray diffraction. In this work, the synthes and X-ray difraction stady of the crystals of a new complex, hexakis (isothiocyanato) erbiu(III) thiocyanate bis(18-Crown-6) dipotassium bis(18-Crown-6) ethanolpotassium], [K2(18-Crown-6)2][K(18-Crown-6)(ETON)]2[Er(NCS)6(SCN)(I)] are described. In crystal I, the alternating [Er(NCS)6]3− anions and binuclear complex cation [K(18-Crown-6)2]2+ from infinite chains via the F-S bonds, while two complex cations [K(18-Crown-6)(ETON)]+ and the statistically disordered SCN− anion between them are linked by the hydragen bonds O-H…S and O-H…N. Complex I contains the host-guest complex cations [K2(18-Crown-6)2)]2+ and [K(18-Crown-6)(ETON)]+ [1]. The alternating octabedral [Er(NCS)6]3− anions and binuclear complex cations [K2(18-Crown-6)2]2+of crystal I form infinite chains via the K-S bonds, while two complex cations [K(18-Crown-6)(EtOH)]+ and the statistically disordered SCN− anion lying between them are linked by interionic hydrogen bonds O-H…S and O-H…N. Complex I contains the host-guest complex cations [K2(18-Crown-6)2]2+ and [K(18-Crown-6)(EtOH)]+ [1].

  • (18-Crown-6)(nitrato-O,O′)potassium and (18-Crown-6)(nitrato-O,O′)potassium(0.91)silver(0.09): Synthesis and crystal structures
    Russian Journal of Inorganic Chemistry, 2008
    Co-Authors: A. N. Chekhlov
    Abstract:

    Two complexes with similar compositions are synthesized: (18-Crown-6)(nitrato-O,O′)potassium (I) and (18-Crown-6)(nitrato-O,O′)potassium(0.91)silver(0.09) (II). Their isomorphic orthorhombic crystals (space group P212121, Z = 4) are studied by X-ray diffraction analysis. Structure I (a = 8.553 A, b = 11.967 A, c = 17.871 A) and structure II (a = 8.540 A, b = 11.956 A, c = 17.867 A) are solved by a direct method and refined by the full-matrix least-squares method in the anisotropic approximation to R = 0.044 (I) and 0.055 (II) for all 2385 (I) and 2379 (II) measured independent reflections. Complex molecules [K(NO3)(18-Crown-6)] in structure I and [K0.91Ag0.09(NO3)(18-Crown-6)] in compound II are of the host-guest type and rather similar in structure. Their 18-Crown-6 and NO3− ligands are disordered over two orientations. The K+ cation in complex I and the mixed cation (K0.91Ag0.09)+ in complex II reside in the cavity of the disordered 18-Crown-6 ligand and is coordinated by its six O atoms and by two disordered O atoms of the NO3−. ligand. The coordination polyhedron (CN = 8) of the K+ cation in complex I and that of (K0.91Ag0.09)+ cation in complex II is a distorted hexagonal pyramid with a base of six O atoms of the 18-Crown-6 ligand and a split vertex at two O atoms of the NO3− ligand.

  • (18-Crown-6)sodium tribromide and (18-Crown-6)potassium triiodide (with an admixture of bromodiiodide): Synthesis and crystal structure
    Russian Journal of Inorganic Chemistry, 2008
    Co-Authors: A. N. Chekhlov
    Abstract:

    Two crystalline host-guest complexes are synthesized and studied using X-ray diffraction analysis: (18-Crown-6)sodium tribromide [Na(18-Crown-6)]+ · Br 3 − (I) and (18-Crown-6)potassium tribromide (with an admixture of bromodiiodide) [K(18-Crown-6)]+ · (Br0.25I2.75)− (II). The structures of compound I (space group P21/n, a = 8.957 A, b = 8.288 A, c = 14.054 A, β = 104.80°, Z = 2) and compound II (space group Cc, a = 8.417 A, b = 15.147 A, c = 17.445 A, β = 99.01°, Z = 4) are solved by a direct method and refined by the full-matrix least-squares method in the anisotropic approximation to R = 0.098 (I) and 0.036 (II) for all 2311 (I) and 2678 (II) independent measured reflections on a CAD-4 automated diffractometer (λMoK α). Similar crystalline complexes I and II exist as infinite chains of alternating complex cations and trihalide anions linked to each other through weak Na-Br or K-I coordination bonds. In [Na(18-Crown-6)]+ and [K(18-Crown-6)]+ complex cations, the Na+ or K+ cation (coordination number is eight) is located in the center of the cavity of the 18-Crown-6 ligand and coordinated by the six O atoms and two terminal Br or I atoms of two trihalide anions lying on opposite sides of the rms plane of the crown ligand.

David Hausmann - One of the best experts on this subject based on the ideXlab platform.

  • Bromine-rich Zinc Bromides: Zn6Br12(18-Crown-6)2×(Br2)5, Zn4Br8(18-Crown-6)2×(Br2)3, and Zn6Br12(18-Crown-6)2×(Br2)2
    Inorganic chemistry, 2016
    Co-Authors: David Hausmann, Claus Feldmann
    Abstract:

    The bromine-rich zinc bromides Zn6Br12(18-Crown-6)2×(Br2)5 (1), Zn4Br8(18-Crown-6)2×(Br2)3 (2), and Zn6Br12(18-Crown-6)2×(Br2)2 (3) are prepared by reaction of ZnBr2, 18-Crown-6, and elemental bromine in the ionic liquid [MeBu3N][N(Tf)2] (N(Tf)2 = bis(trifluoromethylsulfonyl)amide). Zn6Br12(18-Crown-6)2×(Br2)5 (1) is formed instantaneously by the reaction. Even at room temperature, compound 1 releases bromine, which was confirmed by thermogravimetry (TG) and mass spectrometry (MS). The release of Br2 can also be directly followed by the color and density of the title compounds. With controlled conditions (2 weeks, 25 °C, absence of excess Br2) Zn6Br12(18-Crown-6)2×(Br2)5 (1) slowly releases bromine with conconcurrent generation of Zn4Br8(18-Crown-6)2×(Br2)3 (2) (in ionic liquid) and Zn6Br12(18-Crown-6)2×(Br2)2 (3) (in inert oil). All bromine-rich zinc bromides contain voluminous uncharged (e.g., Zn3Br6(18-Crown-6), Zn2Br4(18-Crown-6)) or ionic (e.g., [Zn2Br3(18-Crown-6)]+, [(Zn2Br6)×(Br2)2]2–) building un...

Axel Schulz - One of the best experts on this subject based on the ideXlab platform.

  • Synthese, Charakterisierung und Kristallstrukturen der Pseudohalogen‐Kronenether‐Komplexe [K([18]krone‐6)(X)(OPPh3)] (X = N3–, OCN– und SCN–)
    Zeitschrift für anorganische und allgemeine Chemie, 2001
    Co-Authors: Elmar Kessenich, Kurt Polborn, Axel Schulz
    Abstract:

    Die Kaliumkronenetherkomplexe [K([18]krone-6)(X)(OPPh3)], mit X = N3–, OCN–, und SCN–, werden durch Reaktion von KX mit [18]Krone-6 (1, 4, 7, 10, 13, 16-Hexaoxacyclooctadekan) und Triphenylphosphan in mit UV Licht bestrahltem THF erhalten. Alle drei Kronenetherkomplexe konnten mit Hilfe der Schwingungsspektroskopie und der Rontgenstrukturanalyse charakterisiert werden. Die Kronenetherkomplexe kristallisieren isotyp in der rhombischen Raumgruppe R3m mit drei Molekulen in der Elementarzelle: [K([18]krone-6)(N3)(OPPh3)] (1): Gitterkonstanten bei 293 K: a = b = 14.213(2) A; c = 13.951(2) A; R1 = 0.0249. [K([18]krone-6)(OCN)(OPPh3)] (2): a = b = 14.239(2) A; c = 13.8927(14) A; R1 = 0.0257. [K([18]krone-6)(NCS)(OPPh3)] (3): a = b = 14.339(2) A; c = 14.266(2) A; R1 = 0.0264. Preparation, Characterisation, and Crystal Structures of the Pseudohalogen Crown Ether Complexes [K([18]crown-6)(X)(OPPh3)] (X = N3–, OCN– and SCN–) The potassium crown ether complexes [K([18]Crown-6)(X)(OPPh3)] (with X = N3–, OCN– and SCN–) can be obtained by reaction of KX with 18-Crown-6 (1, 4, 7, 10, 13, 16-hexaoxacyclooctadecane and triphenylphosphane in THF exposed to UV light. All crown ether complexes were characterized by means of vibrational spectroscopy and X-ray diffraction. They crystallize in the rhombic pointgroup R3m with three molecules in the unit cell: [K([18]crown-6) (N3)(OPPh3)] (1): lattice constants at 293 K: a = b = 14.213(2) A; c = 13.951(2) A; R1 = 0.0249. [K([18]crown-6)(OCN)(OPPh3)] (2): a = b = 14.239(2) A; c = 13.8927(14) A; R1 = 0.0257. [K([18]crown-6)(NCS)(OPPh3)] (3): a = b = 14.339(2) A; c = 14.266(2) A; R1 = 0.0264.

  • synthese charakterisierung und kristallstrukturen der pseudohalogen kronenether komplexe k 18 krone 6 x opph3 x n3 ocn und scn
    Zeitschrift für anorganische und allgemeine Chemie, 2001
    Co-Authors: Elmar Kessenich, Kurt Polborn, Axel Schulz
    Abstract:

    Die Kaliumkronenetherkomplexe [K([18]krone-6)(X)(OPPh3)], mit X = N3–, OCN–, und SCN–, werden durch Reaktion von KX mit [18]Krone-6 (1, 4, 7, 10, 13, 16-Hexaoxacyclooctadekan) und Triphenylphosphan in mit UV Licht bestrahltem THF erhalten. Alle drei Kronenetherkomplexe konnten mit Hilfe der Schwingungsspektroskopie und der Rontgenstrukturanalyse charakterisiert werden. Die Kronenetherkomplexe kristallisieren isotyp in der rhombischen Raumgruppe R3m mit drei Molekulen in der Elementarzelle: [K([18]krone-6)(N3)(OPPh3)] (1): Gitterkonstanten bei 293 K: a = b = 14.213(2) A; c = 13.951(2) A; R1 = 0.0249. [K([18]krone-6)(OCN)(OPPh3)] (2): a = b = 14.239(2) A; c = 13.8927(14) A; R1 = 0.0257. [K([18]krone-6)(NCS)(OPPh3)] (3): a = b = 14.339(2) A; c = 14.266(2) A; R1 = 0.0264. Preparation, Characterisation, and Crystal Structures of the Pseudohalogen Crown Ether Complexes [K([18]crown-6)(X)(OPPh3)] (X = N3–, OCN– and SCN–) The potassium crown ether complexes [K([18]Crown-6)(X)(OPPh3)] (with X = N3–, OCN– and SCN–) can be obtained by reaction of KX with 18-Crown-6 (1, 4, 7, 10, 13, 16-hexaoxacyclooctadecane and triphenylphosphane in THF exposed to UV light. All crown ether complexes were characterized by means of vibrational spectroscopy and X-ray diffraction. They crystallize in the rhombic pointgroup R3m with three molecules in the unit cell: [K([18]crown-6) (N3)(OPPh3)] (1): lattice constants at 293 K: a = b = 14.213(2) A; c = 13.951(2) A; R1 = 0.0249. [K([18]crown-6)(OCN)(OPPh3)] (2): a = b = 14.239(2) A; c = 13.8927(14) A; R1 = 0.0257. [K([18]crown-6)(NCS)(OPPh3)] (3): a = b = 14.339(2) A; c = 14.266(2) A; R1 = 0.0264.