Hybridization: Localized Electron Model

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Hybridization Localized Electron Model
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Why Hybridization Occurs

• Example Methane (CH4)
• 4 hydrogens bonded to the central carbon atom
• The 4 electrons involved in bonding on the C atom
  are
• 2s2
• 2p2
• Which of these electrons have higher energy
  levels?
• But all 4 bonds have the SAME energy level.

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Why Hybridization Occurs (continued)

• To accomplish this same energy level bonds
  arrangement, the 4 electron orbitals hybridize
  to a combined s and p orbital, with energy
  somewhere between the two original s and p
  orbitals.

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Carbon Hybridization
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Hybridization Generalizations

• Hybridizations refer to effective pairs!
• A double bond is how many effective pairs?
• A triple bond is how many effective pairs?
• 4 effective pairs sp3 orbitals
• 3 effective pairs sp2 orbitals
• 2 effective pairs ?????
• 5 effective pairs ?????

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sp2 Hybridization

• Example H2CO
• Central atom?
• How many effective pairs around the central atom?
• What electrons on the C atom are involved in
  bonding?
• This time, the 2s2 and 2p2 electrons only need to
  hybridizes to form 3 orbitals.
• You will have 3 sp2 hybrid orbitals and a lone
  original p orbital.

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H2CO Carbon Hybridized Orbitals
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H2CO Oxygen Orbitals

• How many effective pairs exist around the oxygen
  atom in H2CO?
• What type of hybridization is this?
• In the molecule, how may of each of the following
  exist?
• Lone pairs
• Single bonds
• Double bonds
• Hybrid orbitals on the C atom
• Hybrid orbitals on the O atom
• Regular (unhybridized) orbitals on C/O atoms

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sp2 Hybridization and Double Bonds

• s (sigma) bonds join the atoms together in
  single OR multiple bonds.
• In a multiple bond, p bonds are composed of
  overlapping regular p orbitals parallel to the
  main s bond.

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H2CO Orbital Diagram
What is missing from this orbital diagram???
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sp Hybridization

• How many effective pairs would be on the atom?
• If we are still examining C, which electrons (and
  orbitals) are involved in bonding?
• So what would the new orbitals be AFTER
  hybridization?
• Example acetylene (ethyne) C2H2

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dsp3 Hybridization

• How many effective pairs on the atom?
• Why cant we use C as an example?
• Give me an element we CAN use.
• Example 1 (using element provided)
• Example 2 I3-1
• Determine the BEST Lewis structure based on
  formal charges.
• Examine the bond types on each I atom.

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6 Effective Pairs

• What would the hybridization be?
• Give an example of a molecule you have seen
  that has 6 effective pairs.