6 research outputs found

    The dilute A4_4 model, the E7_7 mass spectrum and the tricritical Ising model

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    The exact perturbation approach is used to derive the (seven) elementary correlation lengths and related mass gaps of the two-dimensional dilute A4_4 lattice model in regime 2- from the Bethe ansatz solution. This model provides a realisation of the integrable Ļ•(1,2)\phi(1,2) perturbation of the c=7/10 conformal field theory, which is known to describe the off-critical thermal behaviour of the tricritical Ising model. The E7_7 masses predicted from purely elastic scattering theory follow in the approach to criticality. Universal amplitudes for the tricritical Ising model are calculated.Comment: 24 pages, LaTeX, submitted to Journal of Mathematical Physics. One paragraph added and some minor typos correcte

    Solid-State Syntheses of Coordination Polymers by Thermal Conversion of Molecular Building Blocks and Polymeric Precursors

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    The syntheses and crystal structures of a mononuclear cadmium complex and five novel coordination polymers based on 1,2,4-triazolyl benzoates are presented. The compounds <sub>āˆž</sub><sup>3</sup>[CdĀ­(H-Me-trz-<i>p</i>ba)<sub>2</sub>] (<b>2</b>), <sub>āˆž</sub><sup>3</sup>[CdĀ­(Me-3py-trz-<i>p</i>ba)<sub>2</sub>] (<b>4</b>), and <sub>āˆž</sub><sup>3</sup>[ZnĀ­(H-Me-trz-<i>p</i>ba)<sub>2</sub>] (<b>6</b>) can be obtained by solvothermal synthesis or simple heating of the starting materials in appropriate solvents, and are also accessible by thermal conversion of the complex [CdĀ­(H-Me-trz-<i>p</i>ba)<sub>2</sub>(H<sub>2</sub>O)<sub>4</sub>] (<b>1</b>), the one-dimensional (1D) coordination polymer <sub>āˆž</sub><sup>1</sup>[CdĀ­(Me-3py-trz-<i>p</i>ba)<sub>2</sub>(H<sub>2</sub>O)<sub>2</sub>]Ā·H<sub>2</sub>O (<b>3</b>), and the porous three-dimensional (3D) framework <sub>āˆž</sub><sup>3</sup>[ZnĀ­(H-Me-trz-<i>p</i>ba)<sub>2</sub>]Ā·4H<sub>2</sub>O (<b>5</b>), respectively. The driving force for these conversions is the formation of thermally stable, nonporous, crystalline 3D coordination polymers. The structural transformations are accompanied by the loss of water and reveal significant changes of the coordination spheres of the metal ions caused by a rearrangement of the triazolyl benzoate ligands. Compounds <b>2</b>, <b>4</b>, <b>5</b>, and <b>6</b> exhibit 4- and 5-fold interpenetration of diamondoid networks (<b>dia</b>) and are thermally stable up to 380 Ā°C

    Solid-State Syntheses of Coordination Polymers by Thermal Conversion of Molecular Building Blocks and Polymeric Precursors

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    The syntheses and crystal structures of a mononuclear cadmium complex and five novel coordination polymers based on 1,2,4-triazolyl benzoates are presented. The compounds <sub>āˆž</sub><sup>3</sup>[CdĀ­(H-Me-trz-<i>p</i>ba)<sub>2</sub>] (<b>2</b>), <sub>āˆž</sub><sup>3</sup>[CdĀ­(Me-3py-trz-<i>p</i>ba)<sub>2</sub>] (<b>4</b>), and <sub>āˆž</sub><sup>3</sup>[ZnĀ­(H-Me-trz-<i>p</i>ba)<sub>2</sub>] (<b>6</b>) can be obtained by solvothermal synthesis or simple heating of the starting materials in appropriate solvents, and are also accessible by thermal conversion of the complex [CdĀ­(H-Me-trz-<i>p</i>ba)<sub>2</sub>(H<sub>2</sub>O)<sub>4</sub>] (<b>1</b>), the one-dimensional (1D) coordination polymer <sub>āˆž</sub><sup>1</sup>[CdĀ­(Me-3py-trz-<i>p</i>ba)<sub>2</sub>(H<sub>2</sub>O)<sub>2</sub>]Ā·H<sub>2</sub>O (<b>3</b>), and the porous three-dimensional (3D) framework <sub>āˆž</sub><sup>3</sup>[ZnĀ­(H-Me-trz-<i>p</i>ba)<sub>2</sub>]Ā·4H<sub>2</sub>O (<b>5</b>), respectively. The driving force for these conversions is the formation of thermally stable, nonporous, crystalline 3D coordination polymers. The structural transformations are accompanied by the loss of water and reveal significant changes of the coordination spheres of the metal ions caused by a rearrangement of the triazolyl benzoate ligands. Compounds <b>2</b>, <b>4</b>, <b>5</b>, and <b>6</b> exhibit 4- and 5-fold interpenetration of diamondoid networks (<b>dia</b>) and are thermally stable up to 380 Ā°C

    An Isomorphous Series of Cubic, Copper-Based Triazolyl Isophthalate MOFs: Linker Substitution and Adsorption Properties

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    An isomorphous series of 10 microporous copper-based metalā€“organic frameworks (MOFs) with the general formulas <sub>āˆž</sub><sup>3</sup>[{Cu<sub>3</sub>(Ī¼<sub>3</sub>-OH)Ā­(X)}<sub>4</sub>{Cu<sub>2</sub>(H<sub>2</sub>O)<sub>2</sub>}<sub>3</sub>(H-R-trz-ia)<sub>12</sub>] (R = H, CH<sub>3</sub>, Ph; X<sup>2ā€“</sup> = SO<sub>4</sub><sup>2ā€“</sup>, SeO<sub>4</sub><sup>2ā€“</sup>, 2 NO<sub>3</sub><sup>2ā€“</sup> (<b>1</b>ā€“<b>8</b>)) and <sub>āˆž</sub><sup>3</sup>[{Cu<sub>3</sub>(Ī¼<sub>3</sub>-OH)Ā­(X)}<sub>8</sub>{Cu<sub>2</sub>(H<sub>2</sub>O)<sub>2</sub>}<sub>6</sub>(H-3py-trz-ia)<sub>24</sub>Cu<sub>6</sub>]Ā­X<sub>3</sub> (R = <i>3</i>py; X<sup>2ā€“</sup> = SO<sub>4</sub><sup>2ā€“</sup>, SeO<sub>4</sub><sup>2ā€“</sup> (<b>9</b>, <b>10</b>)) is presented together with the closely related compounds <sub>āˆž</sub><sup>3</sup>[Cu<sub>6</sub>(Ī¼<sub>4</sub>-O)Ā­(Ī¼<sub>3</sub>-OH)<sub>2</sub>(H-Metrz-ia)<sub>4</sub>]Ā­[CuĀ­(H<sub>2</sub>O)<sub>6</sub>]Ā­(NO<sub>3</sub>)<sub>2</sub>Ā·10H<sub>2</sub>O (<b>11</b>) and <sub>āˆž</sub><sup>3</sup>[Cu<sub>2</sub>(H-3py-trz-ia)<sub>2</sub>(H<sub>2</sub>O)<sub>3</sub>] (<b>12</b><sup><b>Cu</b></sup>), which are obtained under similar reaction conditions. The porosity of the series of cubic MOFs with <b>twf-d</b> topology reaches up to 66%. While the diameters of the spherical pores remain unaffected, adsorption measurements show that the pore volume can be fine-tuned by the substituents of the triazolyl isophthalate ligand and choice of the respective copper salt, that is, copper sulfate, selenate, or nitrate

    Synthesis, Crystal Structure, and Solid-State NMR Investigations of Heteronuclear Zn/Co Coordination Networks ī—ø A Comparative Study

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    Synthesis and solid-state NMR characterization of two isomorphous series of zinc and cobalt coordination networks with 1,2,4-triazolyl benzoate ligands are reported. Both series consist of 3D diamondoid networks with four-fold interpenetration. Solid-state NMR identifies the metal coordination of the ligands, and assignment of all <sup>1</sup>H and <sup>13</sup>C shifts was enabled by the combination of <sup>13</sup>C editing, FSLG-HETCOR spectra, and 2D <sup>1</sup>Hā€“<sup>1</sup>H back-to-back (BABA) spectra with results from NMR-CASTEP calculations. The incorporation of Co<sup>2+</sup> replacing Zn<sup>2+</sup> ions in the MOF over the full range of concentrations has significant influences on the NMR spectra. A uniform distribution of metal ions is documented based on the analysis of <sup>1</sup>H <i>T</i><sub>1</sub> relaxation time measurements
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