Room temperature preparations of second and third transition series tetrafluorides and a possible novel structure type for OsF4 and RhF4

The polymeric tetrafluorides, MF4 (M=Mo, Ru, Pd, Re, and Os) have been precipitated from their MF62− salts in liquid anhydrous hydrogen fluoride (aHF) at ∼20 °C. For M=Ru, Os and Pd, AsF5 can be used to displace the tetrafluoride, but this strong F− acceptor is too strongly oxidizing for use in making MoF4 and ReF4, for which SbF5 is effective. X-ray powder diffraction photograph (XRDP) show the MF4 to have the same structures as those from higher temperature preparations, when previously known. XRDP of OsF4 are very like those of RhF4 and indicate a close structural relationship of the pair, and a significant structural difference from the PdF4 type structure adopted by M=Pd, Pt, Ir, and Re. A new, two-dimensional, ‘raft’ structure is proposed for OsF4 and RhF4.