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In 1965, the ?rst metal-metal multiple bond was reported for [R82C13]2_ by F

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In 1965, the ?rst metal-metal multiple bond was reported for [R82C13]2_ by F. Albert Cotton. (a) What is the Isl-electron con?guration for each Re center in this dinuclear complex? (b) What is the highest bond order that can theoretically be achieved for two transition metal centers? Show how two sets of degenerate d—orbitals can combine to achieve this result. How many d-electrons would be required for each metal center to achieve this maximum bond order? (c) The structure of [ReCls]2' has D411 point group symmetry, with the two ReCltl. units in an eclipsed conformation. What is the d-orbital splitting picture for each square planar [ReClaT unit? (d) Consider bringing the two square planar [ReCl4]‘ units together along the z—axis to form Re-Re bonds. Draw an M0 energy level diagram showing the bonding and antibonding d—orbital combinations that would result — do not draw a full MO diagram for [ReZClgFj focus on the d—orbitals only by bringing together the two of the ?‘agments you generated in part (c). Label each M0 you generate as either 6, o“, it, it“, 3, or 5*. What is the Re-Re bond order in [Re2C13]2‘? What is the Re- Re bond order if two electrons are removed to form Re2Cls? (e) There is an energy barrier to rotation about the Re-Re bond axis in [R62Cls]2_. Why do you propose this is the case? (t) Conversely, explain why there would be no comparable barrier to rotation RezCls. (g) Consider that two axial L type ligands are brought in along the z-axis and bind one to each Re center to form [Re2L2Cls]2‘. How would this affect the energy level diagram you constructed in part (d)? Would the Re-Re bond order in [Re2L2Cls]2‘ be increased or decreased relative to [Re2Cls]2'?