Abstract: | Structure and Properties of the Methyltetrafluorophosphate Anion, CH3PF5]— Methyltetrafluorphosphorane reacts with the fluorides NaF, KF, CsF, and (CH3)4NF with formation of the corresponding methylpentafluorophosphates. In case of the K and Cs salts KCH3PF5] · CH3CN and CsCH3PF5] · CH3CN, respectively, are formed using acetonitrile as solvent. The salts are characterized by NMR, IR and Raman spectroscopy. The vibrational frequencies are compared with ab initio calculated data (RHF/6‐31+G*). The RHF/6‐31+G* calculation yields for the almost octahedral anion bond distances of d(PFeq) = 163.7 pm, d(PFax) = 162.0 pm, and d(PC) = 184.8 pm. |