The title compound, C₂₄H₁₅Br₃, crystallizes in the orthorhombic space group P2₁2₁2₁ with three mol­ecules in the asymmetric unit. The crystal was found to be inversion twinned and the appropriate twin law was applied, resulting in R₁ = 0.035 for the experimental data measured at T = 136 K.

The title compound, [Ru₂Cl₃(C₁₀H₁₄)₂]₂[Hg₂Cl₆], contains two [{Ru(C₁₀H₁₄)}₂(μ-Cl)₃]⁺ cations and one [Hg₂Cl₆]²⁻ anion. In the cation, two [Ru(η⁶-p-cymene)] fragments are linked by three bridging Cl atoms. The anion lies on a twofold rotation axis. The coordination geometry of ruthenium is pseudo-octahedral, while the coordination around mercury is highly distorted tetrahedral. The average Ru—Cl bond length is 2.435 Å. The average bridging and terminal Hg—Cl distances are 2.664 and 2.435 Å, respectively.

In the cation of the title compound, [Rh₂Cl₃(C₁₀H₁₅)₂]BF₄, two Rh(η⁵-C₅Me₅) fragments are linked by three bridging Cl atoms. Each rhodium center has a pseudo-octahedral coordination geometry, with a C₅Me₅ group occupying three positions and three Cl atoms completing the coordination. The average Rh—Cl bond length is 2.450 Å and the average Rh—Cl—Rh bond angle is 81.6°.

In the title compound, [Hg₂Cl₄(C₁₈H₃₃P)₂], there are two independent centrosymmetric Hg^II dimers, the asymmetric unit containing half of each. The coordination about each Hg atom is highly distorted tetrahedral, three sites being occupied by one terminal and two bridging Cl atoms, and the remaining site by the P atom of a tri­cyclo­hexyl­phosphine ligand (PCy₃). The Hg atoms in the dimers are 3.792 (3) and 3.940 (3) Å apart and are thus non-bonded.