Syntheses of Phosphoryl Chloro‐ and Bromofluorides and Crystal Structures of POFCl2 and POF2Cl

A simple procedure for the preparation of phosphoryl chlorofluorides, POFCl₂ and POF₂Cl, by chlorination of the appropriate potassium fluorophosphates, K₂PO₃F and KPO₂F₂, respectively, with PCl₅ is described. The analogous bromination with PBr₅ gives POFBr₂ and POF₂Br. However, due to low yields and high content of impurities, this method is not suitable for the synthesis of the former compound. Both chlorofluorides were crystallized from the melt at low temperatures and their crystal structures were determined by X‐ray diffraction at ?153 °C. Distorted tetrahedral molecules of POFCl₂ are only weakly associated through intermolecular O···Cl contacts forming infinite chains similarly as in crystalline POCl₃. In POF₂Cl, however, the chains are formed by the O···P contacts, and an additional P–O···Cl bridging leads to their linkage into a double‐chain structure.