STUDIES OF POLYHALIDES, 33 POLYIODIDES OF THE NICKEL HEXAMMINE COMPLEX - NICKELHEXAMMINE BISTRIIODIDE [NI(NH3)(6)](I-3)(2) AND NICKELHEXAMMINE BISPENTAIODIDE [NI(NH3)(6)](I-5)(2)

The compounds [Ni(NH3)(6)](I-3)(2) and [Ni(NH3)(6)](I,)2 have been pre pared by the reaction of stoichiometric amounts of [Ni(NH3)(6)]Cl-2, K I, and I-2 in water. The already known triiodide crystallizes in the m onoclinic space group C2/c with a = 1541.0(10), b = 1521.6(8), c = 876 .1(7) pm, beta = 101.44(6)degrees and Z = 4. The new pentaiodide cryst allizes in the monoclinic space group P2(1)/n with a = 899.6(4), b = 1 681.6(5), c = 946.8(7) pm, beta = 110.90(5)degrees and Z = 2. Both com pounds contain nearly octahedral cations [Ni(NH3)(6)](2+) and simultan eously a linear and a bent triiodide ion I(3)(-)with nearly equal bond lengths or a unsymmetrical V-shaped pentaiodide ion I-5-which is line d up to a new type of pentaiodide chain.