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3. (20 points) SbFs is a potent Lewis acid which is also a component of many superacid mixtures such as "Magic Acid". Combining SbFs with HF in a 1:2 ratio produces fluoroantimonic acid (HF]SbF6, the strongest known superacid. Superacid mixtures have been used to create exotic species such as pentacoordinate carbocations from the protonation of alkanes! (See: Olah, G. J. Org. Chem., 2005, 70 (7), 2413-2429.) a. SbFs has a trigonal bipyramidal geometry as a neutral compound, but when it acts as a Lewis acid, its structure distorts toward a square pyramidal geometry with Cow symmetry, as shown below: F F Fire... F-Sb 一次 Sb F F F D3h C4v Use the car character table to construct a reducible representation of the fluorine group orbitals for square pyramidal SbFs. You may assume that only a bonding will be significant, i.e. each fluorine atom can be simplified to a single p orbital oriented toward the central Sb atom. Reduce your representation to the component irreducible representations. (Hint: There should be five group orbitals.) b. Use the projection operator method to determine the contributions of each fiucrine atomic orbital to the group orbitals you found in part a and sketch the resulting SALCS. Construct an mo diagram for square pyramidal SbFs showing all o and a bonding and antibonding Mos. (Don't forget to include nonbonding orbitals for the fluorine atornic oroitais we ignored in part a!) d. When SbFs combines with HF to form fluoroantimonic acid, the fluoride anion from HF attaches to the Sb center to form SbFe and the H' ion attaches to another molecule of HF. Use your MO diagram from partc to explain this behavior. How does SbFs act as a Lewis acid? C.