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Published byPhoebe Pearson Modified over 9 years ago
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More on: Molecular Orbitals Pericyclic Reactions Electrocyclic Reactions
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Pi Bonding MO (bond along x-axis; orbitals in xy plane) x y z mirror in yz plane Symmetrical mirror plane (yz)
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Pi Bonding MO (bond along x-axis; orbitals in xy plane) x y z rotate 180 o about z-axis in xy-plane
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Pi Bonding MO (bond along x-axis; orbitals in xy plane) x y z Antisymmetric about the C 2 axis
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Pi Antibonding MO (bond along x-axis; orbitals in xy plane) x y z mirror in yz plane Antisymmetric mirror plane (yz)
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Pi Bonding MO (bond along x-axis; orbitals in xy plane) x y z rotate 180 o about z-axis in xy-plane Symmetric about C 2 axis
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Pi Bond MO MirrorC 2 - axis A S Bonding S A Antibonding node
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Allylic Resonance Energy of an isolated p-orbital allyl cationallyl radicalallyl anion bonding - 0 nodes SA anti-bonding - 2 nodes SA non-bonding - 1 node AS
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M.O.s of 1,3-Butadiene Highest Occupied Molecular Orbital Lowest Unoccupied Molecular Orbital Energy of isolated p-atomic orbital (A.O.) bonding M.O. - 2 HOMO AS bonding M.O. - 1 SA anti-bonding M.O. - 3 * LUMO SA anti-bonding M.O. - 4 * AS
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SA AS SA HOMO LUMO Orbital Symmetry in the Diels-Alder Reaction Equal HOMO-LUMO Energy Difference
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AS SA AS HOMO LUMO AS SA EWG Diels-Alder Reaction with a Deactivated Dienophile EWG Lowers LUMO Energy
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Dienophile LUMO ( 3 *) Diene HOMO ( 2 ) The Diels-Alder Reaction Transition State EWG
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HOMO thermal rxn. h EE HOMO photochemical rxn. Photochemical Excitation in 1,3-Butadiene
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1,3-Butadiene Cyclobutene Conrotatory Disrotatory h 22 3*3*
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but one cyclobutene is just like another cyclobutene enter stereochemistry
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1,3-Butadiene Cyclobutene Conrotatory Disrotatory h 22 Me HH H H 3*3* H H
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Thermal Con Thermal Con h Dis h Dis Stereocontrol in the 1,3-Diene Cyclization E,E E,Z trans cis
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