A new variety of PdF2 synthesised by low-temperature reaction in anhydrousHF

A new variety of palladium difluoride has been prepared via a low temperatu re (LT) process in anhydrous hydrogen fluoride (aHF). Reaction between solu tions of Pd(AsF6)(2) and CsF in aHF results in the precipitation of the lig ht-brown LT form of PdF2. This phase crystallises in the Pa3 cubic space gr oup with a = 532.4(1) pm and can be derived from the fluorite structure. Th e co-ordination of Pd is: 6F at 217.6(3) pm + 2F at 316.8(3) pm. The struct ural network can be described either as PdF8 rhombohedra sharing edges-as M X8 cubes in the fluorite-or as flattened PdF6 octahedra sharing corners. Ea ch F atom is common to 3 octahedra. The relationships with the fluorite and pyrite structures have been raised. LT-PdF2 is antiferromagnetic, with a N eel temperature evaluated at around 180 K. (C) 2001 Elsevier Science B.V. A ll rights reserved.