Institut für nachhaltige Chemie & Katalyse mit Bor (ICB), Institut für Anorganische Chemie, Julius-Maximilians-Universität Würzburg, Am Hubland, 97074, Würzburg, Germany.
Institut für Organische Chemie & Center for Nanosystems Chemistry, Julius-Maximilians-Universität Würzburg, Am Hubland, 97074, Würzburg, Germany.
Chemistry. 2019 Mar 7;25(14):3560-3574. doi: 10.1002/chem.201804698. Epub 2019 Feb 11.
High-yield syntheses up to molar scales for salts of [BH(CN) ] (2) and [BH (CN) ] (3) starting from commercially available Na[BH ] (Na5), Na[BH (CN)] (Na4), BCl , (CH ) SiCN, and KCN were developed. Direct conversion of Na5 into K2 was accomplished with (CH ) SiCN and (CH ) SiCl as a catalyst in an autoclave. Alternatively, Na5 is converted into Na[BH{OC(O)R} ] (R=alkyl) that is more reactive towards (CH ) SiCN and thus provides an easy access to salts of 2. Some reaction intermediates were identified, for example, Na[BH(CN){OC(O)Et} ] (Na7 b) and Na[BH(CN) {OC(O)Et}] (Na8 b). A third entry to 2 and 3 uses ether adducts of BHCl or BH Cl such as the commercial 1,4-dioxane adducts that react with KCN and (CH ) SiCN. Alkali metal salts of 2 and 3 are convenient starting materials for organic salts, especially for low viscosity ionic liquids (ILs). [EMIm]3 has the lowest viscosity and highest conductivity with 10.2 mPa s and 32.6 mS cm at 20 °C known for non-protic ILs. The ILs are thermally, chemically, and electrochemically robust. These properties are crucial for applications in electrochemical devices, for example, dye-sensitized solar cells (Grätzel cells).
从商业上可获得的 Na[BH ] (Na5)、Na[BH (CN)] (Na4)、BCl 、(CH ) SiCN 和 KCN 出发，开发了[BH(CN) ] (2)和[BH (CN) ] (3)盐的高达摩尔规模的高产合成方法。在高压釜中，用(CH ) SiCN 和(CH ) SiCl 作为催化剂，将 Na5 直接转化为 K2。或者，Na5 被转化为对(CH ) SiCN 更具反应性的 Na[BH{OC(O)R} ] (R=烷基)，从而更容易获得 2 的盐。鉴定了一些反应中间体，例如 Na[BH(CN){OC(O)Et} ] (Na7b)和 Na[BH(CN) {OC(O)Et}] (Na8b)。第三种方法是使用 BHCl 或 BH Cl 的醚加合物，例如商业的 1,4-二恶烷加合物，它们与 KCN 和(CH ) SiCN 反应。2 和 3 的碱金属盐是有机盐，特别是低粘度离子液体 (IL) 的方便起始材料。[EMIm]3 具有已知非质子 IL 中最低的粘度和最高的电导率，在 20°C 时为 10.2 mPa·s 和 32.6 mS·cm。IL 具有热、化学和电化学稳定性。这些特性对于电化学装置中的应用至关重要，例如染料敏化太阳能电池 (Grätzel 电池)。
