SYNTHESIS AND CHARACTERIZATION OF TERNARY ALKALINE-EARTH TRANSITION-METAL HYDRIDES CONTAINING OCTAHEDRAL [RU(II)H6]4- AND [OS(II)H6]4- COMPLEXES

Mg2RuH6, Ba2RuH6, Ca2OsH6, Sr2OsH6, and Ba2OsH6 with the K2PtCl6-type structure have been synthesized. Solid state IR spectroscopy applied to these and other, already known, ternary hydrides from the iron triad shows M{single bond}H stretching frequencies in the 1500-1850 cm-1 energy range, which are correlated with the size of the cube of counterions surrounding the complexes. Lower frequencies are found with larger counterions. The ν(M{single bond}H) value increases on going from iron to osmium, indicating that H- ions are well capable of stabilizing divalent osmium, which so far has been found exclusively with good electron-accepting ligands. © 1991 Academic Press, Inc.