Die Tetracyanoborsäuren H[B(CN)4]·n H2O,n = 0, 1, 2 |
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| Authors: | Torsten Küppers Eduard Bernhardt Christian W. Lehmann Dr. Helge Willner Prof. Dr. |
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| Affiliation: | 1. Wuppertal, FB C Anorganische Chemie der Universit?t;2. Max‐Planck‐Institut für Kohlenforschung, Kaiser‐Wilhelm‐Platz 1, 45470 Mülheim an der Ruhr, Tel.: (+49)208‐306‐2174, Fax: (+49)208‐306‐2989;3. Christian W. Lehmann, Max‐Planck‐Institut für Kohlenforschung, Kaiser‐Wilhelm‐Platz 1, 45470 Mülheim an der Ruhr, Tel.: (+49)208‐306‐2174, Fax: (+49)208‐306‐2989;4. Helge Willner, FB C – Mathematik und Naturwissenschaften, Anorganische Chemie, Gau?str. 20, D‐42119 Wuppertal, Deutschland, Tel.: (+49)202‐439‐2517, Fax: (+49)202‐439‐3053 |
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| Abstract: | The Tetracyanoboronic Acids H[B(CN)4]·n H2O, n = 0, 1, 2 Treatment of an aqueous solution of Na[B(CN)4] with an acidic cation exchange resin leads to a solution of the strong tetracyanoboronic acid. Evaporation of the solution at room temperature yields colourless single crystals of [H5O2][B(CN)4] ( , a = 9.5830(2) Å, c = 14.25440(3) Å, Z = 1). Further drying of [H5O2][B(CN)4] (mp. 115 °C) in vacuum at 50 °C gives polycrystalline [H3O][B(CN)4] (P63mc, a = 8.704(1) Å, c = 6.152(1) Å, Z = 2), which is thermally stable up to 145 °C. The anhydrous polycrystalline acid H[B(CN)4] is formed quantitatively by reacting Me3SiNCB(CN)3 with gaseous HCl. This acid starts to decompose at 190 °C with loss of HCN. All three acids were further characterized by vibrational spectroscopy, and elemental analysis. |
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| Keywords: | Tetracyanoborates Crystal structure Vibrational spectroscopy Thermal stability |
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