title: Stabilization by Hydrogen. Synthetic and Structural Studies of the Zintl Phase Ba(5)Ga(6)H(2).
abstract: Synthesis of the phase formerly reported as Ba(5)Ga(6) succeeds only in the presence of hydrogen. The heavy atom structure of Ba(5)Ga(6)H(2) has been redetermined by single-crystal X-ray diffraction (trigonal P3c1, Z = 2, a = 7.7698(2) Å, c = 14.3902(7) Å), and the hydrogen positions have been elucidated by time-of-flight neutron powder diffraction. The unit cell contains isolated slightly distorted octahedra Ga(6)(8)(-) with barium cations over all edges. Hydride is bound in two types of barium tetrahedra [d(Ba-H) = 2.61-2.62 Å]. The stoichiometry is appropriate for a Zintl phase: (Ba(2+))(5)Ga(6)(8)(-)(H(-))(2).
authors.affiliation: Department of Chemistry and Ames Laboratory-DOE,(1) Iowa State University, Ames, Iowa 50011.
authors.forename: Robert W.
authors.initials: RW
authors.lastname: Henning
authors.forename: E. Alejandro
authors.initials: EA
authors.lastname: Leon-Escamilla
authors.forename: Jing-Tai
authors.initials: JT
authors.lastname: Zhao
authors.forename: John D.
authors.initials: JD
authors.lastname: Corbett