Rhodium pentafluoride is an inorganic compound with the formula Rh<sub>4</sub>F<sub>20</sub>. It is a red solid. It is prepared by fluorination of rhodium trifluoride at 400 ðC.
According to X-ray crystallography, the Rh centers are octahedral. The structure is very similar to that of the related ruthenium pentafluoride, osmium pentafluoride, and iridium pentafluoride. All are tetrameric, meaning that they have the molecular structure [MF<sub>5</sub>]<sub>4</sub>. The M-F distances for the bridging fluoride ligands are typically about 0.2 àlonger than the Rh-F distances for the nonbridging fluoride ligands. In the case of rhodium pentafluoride, these distances average 1.999(4) and 1.808(8) à. The Rh-F-Rh angles average 135ð, which leads to a ruffled structure. In contrast, the M-F-M centers are linear in the pentafluorides of niobium, tantalum, molybdenum, and tungsten.