Coordination Chemistry.

(b)
When inspecting the structures of the metal-metal bonded complex ions [Mo2Cl8]4-, [Re2Cl8]2-, and [Os2Cl8]2-, it is observed that the chlorido ligands on the metal centres have an eclipsed arrangement in [Mo2Cl8]4- and [Re2Cl8]2-, but they are staggered in [Os2Cl8]2-.
(i) Draw a molecular orbital energy level diagram (obtained by overlap of the appropriate d-orbitals) that can be used to describe the metal-metal bonding in these complexes.
(ii) For each of the three complexes, [Mo2Cl8]4-, [Re2Cl8]2-, and [Os2Cl8]2-, show how electrons fill these molecular orbitals.

(iii) With the aid of the molecular orbital energy level diagrams provided for your answer to (ii) above explain why the chlorido ligands in [Mo2Cl8]4- and [Re2Cl8]2- are eclipsed whereas in [Os2Cl8]2- they are staggered.