五氟化磷制备过程的GC-MS-SIM法评价与监测

Monitoring and evaluation of preparation process of PF_5 by GC-MS-SIM

比较4种PF5的制备新方法,分别为P2O5和CaF2固-固加热法、KPF6直接加热法、PCl5和CaF2固-固加热法、KPF6和PCl5固-固加热法,并讨论PF5在无水乙醚和乙腈中溶解情况。对4种不同方法反应生成的PF5按照最佳方案经过溶剂预处理,通过GC-MC-SIM法进行评价。研究结果表明:采用P2O5和CaF2固-固加热法生成高纯度的PF5气体,为制备PF5的最优方法,而采用其他3种方法均出现杂质气体产物,分别为PF3和POF3等;对P2O5和CaF2固-固加热法制备PF5过程进行GC-MS-SIM监测,制备过程的最优化方法为:CaF2和P2O5固-固相在质量比≥1:2时,于280℃加热3h。采用该方法时,原材料无毒、易得,制备过程易控制,优于目前传统的PF5制备方法。

Four novel preparation methods of PF5 were compared, i.e., solid-solid-heated method of P2O5 and CaF2, solid-directly-heated method of KPF6, solid-solid-heated method of PCl5 and CaF2, solid-solid-heated method of KPF6 and PCl5. Dissolution situation of PF5 in non-aqueous aether and acetonitrile was discussed, PF5 produced from new various methods were pretreated under optimal condition by dissolving in non-aqueous solvent and evaluated by GC-MS-SIM. Evaluation results indicate that PF5 of high-purity can be generated by solid-solid-heated method of P205 and CaF2, which is the best choice of preparation of PFs, while impurity gases such as PF3, POF3 are generated by the other three methods respectively. Monitoring the preparation of PF5 by P2O5 and CaF： solid-solid -heated method is attached great importance. Eventual results of monitoring indicate that optimal condition of preparation is as follows： P2O5 and CaF2 is heated at 280 ℃ for 3 h when their solid mass ratio is not less than 1：2. In the optimal preparation, reaction materials are intoxic and easily received, preparation process can be easily controlled, which is approved in excellence at present.