A second polymorph of 1,1,4,4-tetra­methyl­piperazinium penta­bromo­thallate(III)

A new polymorph of the title compound, (C8H20N2)[TlBr5], contains cations located about crystallographic centres of inversion and trigonal‐bipyramidal anions which have a C2 axis passing through the equatorial plane of the anion. The anion has the least distorted geometry seen so far in any structure possessing this anion and the axial Tl—Br bonds are about 0.13 Å longer than the equatorial Tl—Br bonds, consistent with related structures. The anion in the initially reported polymorph has lower symmetry and a greater distortion of the trigonal‐bipyramidal coordination.