SYNTHESIS AND X-RAY STRUCTURE OF [H(3)O(-CROWN-6] [BR-BR-BR-[ - A COMPOUND CONTAINING BOTH H3O+ AND A LINEAR AND SYMMETRICAL BR-3(-) ION CRYSTALLIZED FROM AROMATIC SOLUTION().18)

[H3O+ . 18-crown-6][Br-Br-Br-] crystallizes in the triclinic space gro up P1BAR with a = 6.105(1), b = 8.658(1), c = 11.072(1)angstrom, alpha = 71.35(1), beta = 77.58(1), gamma = 71.09(1)-degrees, and D(c) = 1.6 8 g cm-3 for Z = 1. Refinement based on 1112 observed reflections led to R = 0.044. The cation exhibits a planar oxonium ion bonded symmetri cally to the 18-crown-6 (O(oxonium) resides 0.092 angstrom out of the plane of the crown ether oxygen atoms). The anion also resides on a ce nter of inversion with Br-Br = 2.530(1)angstrom.