In the title compound, trans-[(MoCl2)-Cl-III(C5H5N)(4)]Br-3, the Cl an
d pyridine N atoms define a slightly distorted octahedron around the M
o atom. Both cations and anions lie on twofold axes. Pyridine rings wh
ich are located trans with respect to one another are staggered. The t
ribromide ion, Br-3(-), is essentially linear.