K3PDH3, A COMPLEX HYBRID WITH LINEAR [PDH22-]-GROUPS

The ternary palladium hydride K3PdH3 has been synthesized by the reaction of potassium hydride with palladium sponge in a pure hydrogen atmosphere. The crystal structure was determined by X-ray investigations on powdered samples and a neutron diffraction experiment on the deuterated compound. The room temperature modification (space group P42/mnm) contains linear [PdH22-] groups and additional hydride ions which are coordinated by potassium ions exclusively. In the cubic high temperature modification (space group Pm3m) the movements of the [PdH22-] groups result in a structure in which the arrangement of the metal cations correspond to the Cu3Au type. © 1990.