RbBa2(N3)5:: a new ternary azide

Rubidium dibarium penta-azide, RbBa2(N-3)(5), was prepared from an aqueous solution of the binary azides at room temperature. It crystallizes in the monoclinic system (space group P2/n). Two central atoms of azide groups occupy the 2c ((1) over bar) and 2b ((1) over bar) positions, another azide group lies completely on a twofold axis (2f), while Rb atoms are situated in 2e (2) positions. The crystal structure of RbBa2(N-3)(5) can be regarded as a distorted AlB2-type arrangement of the metal atoms, with the azide groups occupying the voids between the cations. This results in coordination numbers of 8 (Rb) and 10 (Ba). The N-N distances are in the range 1.169 (8)-1.190 (5) angstrom, typical for the azide group.