MG3RUH6, A COMPLEX HYDRIDE CONTAINING 2 TYPES OF HYDROGEN-ATOMS DIFFERING IN THEIR BONDING

The ternary ruthenium hydride Mg3RuH6 was successfully prepared by rea cting magnesium or magnesium hydride with ruthenium under a hydrogen p ressure of 90 bar. The structure of the rusty brown product was determ ined by X-ray investigations on powdered samples and elastic neutron p owder diffraction experiments on the deuterated compound. Mg3RuH6 Crys tallizes in the orthorhombic space group Cmcm. The atomic arrangement contains two differently bonded types of hydrogen atoms. One forms com plex ruthenium-hydrogen anions, whereas the other is surrounded exclus ively by magnesium cations. The relationship with the magnesium-ruthen ium hydrides Mg2RuH4 and Mg2RuH6 is discussed.