Rb3ReH10, a new rhenium(VII) hydride - High pressure synthesis and crystalstructure

The ternary hydride Rb3ReH10 can be synthesised by reacting rubidium hydrid e with rhenium in a hydrogen atmosphere under a pressure of above 4000 bar in a temperature range between 700 and 870 K. X-ray investigations on powde r samples and elastic neutron diffraction experiments on the deuterated com pound led to the crystal structure. According to the formula [ReD9]DRb3 the atomic arrangement of the room temperature modification corresponds to tha t of the perowskite structure type. The coordination polyhedron of the hydr ogen atoms that surround each rhenium atom can be described crystallographi cally as a statistical occupation of two 24-fold positions with hydrogen. I n the orthorhombic low-temperature modification the deuterium ligands are a rranged in ordered positions. They form monocapped square antiprisms. Magne tic susceptibility measurements revealed Rb3ReD10 to be diamagnetic.