Six new bromothallate(III)-containing salts with different alkyl diammonium cations have been prepared from bromide containing solutions and studied by single-crystal X-ray crystallographic analyses. The N,N'-diethyl-N,N,N',N'-tetramethyl-1,2-ethylenediammonium, N-methyl-1,3-propanediammonium, N,N,N',N'-tetramethyl-1,3-propanediammonium and N,N,N',N'-tetraethyl-1,2-ethylenediammonium cations yield complexes (I, II, III and IV, respectively) with the [TlBr 5 ] 2 - anionic stoichiometry. For I and II, both complexes contain the [TlBr 5 ] 2 - anion. In complex II, this appears as a distorted octahedron with one long Tl...Br2' contact of 3.632(4) Å from an adjacent anion, thus completing the hexacoordination about an otherwise distorted square pyramid. On the other hand, for III and IV, both complexes contain a tetrahedral [TlBr 4 ] - anion together with an isolated, but hydrogen-bonded, Br - anion. The 1,5-hexanediammonium complex (V) contains tetrahedral [TlBr 4 ] - , slightly distorted octahedral [TlBr 6 ] 3 - and Br - anions. The asymmetric unit of the N,N-diethyl-1,3-propanediammonium salt (VI) contains one cation and half of each of a [TlBr 4 ] - and an axially compressed octahedral [TlBr 6 ] 3 - anion. Extensive hydrogen-bonded networks exist in complexes II-VI. N H...Br hydrogen bonds generally have a significant influence on the nature of the anions present in species with the formal [TlBr 5 ] stoichiometry.