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A G Sykes - One of the best experts on this subject based on the ideXlab platform.
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preparation of a novel Thallium Compound of core formula timo6s88
Polyhedron, 1996Co-Authors: J E Varey, A G SykesAbstract:Abstract A new mixed metal cluster of molybdenum, sulfur and Thallium has been prepared. The complex can be prepared by the reaction of [Mo3S4(H2O)9]4+ with Thallium metal, but preparation is more successful using sodium borohydride reduction of a solution of [Mo3S4(H2O)9]4+ in the presence of solid TlCl. The new Compound occurs as a turquoise solution when eluted in 4 M HCl or Hpts (p-toluenesulfonic acid) from a Dowex chromatography column. ICP analysis on the pure solution indicates a ratio of 5.92:1 for the ratio Mo:Tl, confirming the proposed core formula of TlMo6S88+. The charge on the core has been confirmed as 8+ using stoichiometric experiments with ferric solutions. The Compound has proven to be thermally unstable, eluting only from ice-cooled columns. On warming a solution from 10 to 25°C, a gas can be seen to evolve, presumably hydrogen. The thermal instability has been investigated further to yield values of ΔH‡ = 79 kJ mol −1 , ΔS‡ = −39 mol −1 .
J E Varey - One of the best experts on this subject based on the ideXlab platform.
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preparation of a novel Thallium Compound of core formula timo6s88
Polyhedron, 1996Co-Authors: J E Varey, A G SykesAbstract:Abstract A new mixed metal cluster of molybdenum, sulfur and Thallium has been prepared. The complex can be prepared by the reaction of [Mo3S4(H2O)9]4+ with Thallium metal, but preparation is more successful using sodium borohydride reduction of a solution of [Mo3S4(H2O)9]4+ in the presence of solid TlCl. The new Compound occurs as a turquoise solution when eluted in 4 M HCl or Hpts (p-toluenesulfonic acid) from a Dowex chromatography column. ICP analysis on the pure solution indicates a ratio of 5.92:1 for the ratio Mo:Tl, confirming the proposed core formula of TlMo6S88+. The charge on the core has been confirmed as 8+ using stoichiometric experiments with ferric solutions. The Compound has proven to be thermally unstable, eluting only from ice-cooled columns. On warming a solution from 10 to 25°C, a gas can be seen to evolve, presumably hydrogen. The thermal instability has been investigated further to yield values of ΔH‡ = 79 kJ mol −1 , ΔS‡ = −39 mol −1 .
John D Corbett - One of the best experts on this subject based on the ideXlab platform.
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na2k21tl19 a novel Thallium Compound containing isolated tl57 and tl99 groups a new hypoelectronic cluster
Journal of the American Chemical Society, 1994Co-Authors: Zhenchao Dong, John D CorbettAbstract:The title Compound is synthesized in high yield by fusion of the elements in sealed Ta containers followed by slow cooling to and annealing at 250[degrees]C. The structure was established by single crystal means (Cmcm, Z = 4, a = 11.345 (2) [angstrom], b = 13.807 (3) [angstrom], c = 41.832 (8) [angstrom], R/R[sub w] = 5.3/4.3%). The independent unit contains two Tl[sub 5] and one Tl[sub 9] units ordered in layers and well separated by the cations which bond to, and bridge between, faces, edges, and vertices of the clusters. The sodium appears essential in this role. The former cluster, a distorted trigonal bipyramid (C[sub m] symmetry), is proportioned as is Pb[sub 5][sup 2[minus]], etc. and should be analogously formulated as the isoelectronic Tl[sub 5][sup 7[minus]] according to EHMO calculations. The new Tl[sub 9] geometry (C[sub 2v], d(Tl-Tl) = 3.13-3.44 [angstrom]) can be obtained by substantial elongation of two side edges of a tricapped trigonal prism (D[sub 3h]) so that the intervening face-capping atom moves close to that face and becomes eight-bonded. MO calculations illustrate how this distortion of either Bi[sub 9][sup 5+]- or B[sub 9]H[sub 9][sup 2[minus]]- like polyhedra affords a hypoelectronic state for Tl[sub 9][sup 9[minus]] (2nmore » skeletal electrons). 41 refs., 5 figs., 2 tabs.« less
K Vidyasagar - One of the best experts on this subject based on the ideXlab platform.
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solid state synthesis and characterization of novel aluminophosphates a3al2p3o12 a na k rb tl influence of a ions on the coordination of aluminum
Inorganic Chemistry, 2000Co-Authors: R N Devi, K VidyasagarAbstract:Four aluminophosphates, A3Al2P3O12 (A = Na, K (1), Rb (2), Tl (3)), have been synthesized by solid-state reactions and characterized by X-ray diffraction and NMR and IR spectroscopic techniques. Aluminum has trigonal bipyramidal coordination in the Thallium Compound and tetrahedral coordination in the others. Potassium, rubidium and Thallium analogues have been structurally characterized by single-crystal X-ray diffraction and found to possess three-dimensional (Al2P3O12)3- anionic frameworks with channels occupied by A+ countercations. These frameworks are built from corner connections of PO4 tetrahedra with AlO4 tetrahedra in 1 and 2 and with AlO5 trigonal bipyramids in 3. Pertinent crystal data are as follows: for 1, orthorhombic space group Pna21, a = 8.685(2) A, b = 16.947(2) A, c = 8.458(3) A, Z = 4; for 2, orthorhombic space group Cmc21, a = 17.164(2) A, b = 8.6270(6) A, c = 8.8140(14) A, Z = 4; for 3, orthorhombic space group Pna21, a = 6.1478(15) A, b = 10.396(3) A, c = 17.787(5) A, Z = 4. Compo...
Zhenchao Dong - One of the best experts on this subject based on the ideXlab platform.
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na2k21tl19 a novel Thallium Compound containing isolated tl57 and tl99 groups a new hypoelectronic cluster
Journal of the American Chemical Society, 1994Co-Authors: Zhenchao Dong, John D CorbettAbstract:The title Compound is synthesized in high yield by fusion of the elements in sealed Ta containers followed by slow cooling to and annealing at 250[degrees]C. The structure was established by single crystal means (Cmcm, Z = 4, a = 11.345 (2) [angstrom], b = 13.807 (3) [angstrom], c = 41.832 (8) [angstrom], R/R[sub w] = 5.3/4.3%). The independent unit contains two Tl[sub 5] and one Tl[sub 9] units ordered in layers and well separated by the cations which bond to, and bridge between, faces, edges, and vertices of the clusters. The sodium appears essential in this role. The former cluster, a distorted trigonal bipyramid (C[sub m] symmetry), is proportioned as is Pb[sub 5][sup 2[minus]], etc. and should be analogously formulated as the isoelectronic Tl[sub 5][sup 7[minus]] according to EHMO calculations. The new Tl[sub 9] geometry (C[sub 2v], d(Tl-Tl) = 3.13-3.44 [angstrom]) can be obtained by substantial elongation of two side edges of a tricapped trigonal prism (D[sub 3h]) so that the intervening face-capping atom moves close to that face and becomes eight-bonded. MO calculations illustrate how this distortion of either Bi[sub 9][sup 5+]- or B[sub 9]H[sub 9][sup 2[minus]]- like polyhedra affords a hypoelectronic state for Tl[sub 9][sup 9[minus]] (2nmore » skeletal electrons). 41 refs., 5 figs., 2 tabs.« less