MOLECULAR GEOMETRY

• class AB2

  -linear arrangement of electron pairs

  -linear (molecular geometry)
• class AB3

  -trigonal planar arrangement of electron pairs

  -trigonal planar (molecular geometry)
• class AB4

  -tetrahedral arrangement of electron pairs

  -tetrahedral (molecular geometry)
• class AB5

  -trigonal bipyramidal arrangement of electron pairs

  -trigonal bipyramidal (molecular geometry)
• class AB6

  -octahedral arrangement of electron pairs

  -octahedral (molecular geometry)
• class AB2E

  -trigonal planar arrangement of electron pairs

  -bent (molecular geometry)
• class AB3E

  -tetrahedral arrangement of electron pairs

  -trigonal pyramidal (molecular geometry)
• class AB2E2

  -tetrahedral arrangement of electrons

  -bent (molecular geometry)
• class AB4E

  -trigonal bipyramidal arrangement of electron pairs

  -distorted tetrahedon (molecular geometry)
• class AB3E2

  -trigonal bipyramidal arrangement of electron pairs

  -t-shaped (molecular geometry)
• class AB2E3

  -trigonal bipyramidal arrangement of electron pairs

  -linear (molecular geometry)
• class AB5E

  -octahedral arrangement of electron pairs

  -square pyramidal (molecular geometry)
• class AB4E2

  -octahedral arrangement of electron pairs

  -square planar (molecular geometry)
• dipole moments

  -H2O

  -SO2

  -CH2Cl2

  -HF

  -HCl

  -HBr

  -HI

  -H2S

  -NH3
• Linear

  • BeCl2
  • HgCl2
• Trigonal Planar

  • BF3
• Tetrahedral

  • CH4
  • NH4
• Trigonal Bipyramidal

  • PCl5
• Octahedral

  • SF6
• Bent

  • SO2
  • H2O
• Trigonal Pyramidal

  • NH3
• Distorted Tetrahedon

  • SF4
• T-Shaped

  • CIF3
• Linear

  • I3
• Square Pyramidal

  • BrF5
• Square Planar

  • XeF4
• Hybridization – mixing of two or more atomic orbitals to form a new set of hybrid orbitals.
• Valence bond theory – bonds are formed by sharing of e - from overlapping atomic orbitals.
• Valence shell electron pair repulsion (VSEPR) model: Predict the geometry of the molecule from the electrostatic repulsions between the electron (bonding and nonbonding) pairs
• Sigma bond – electron density between the 2 atoms
• Pi bond – electron density above and below plane of nuclei of the bonding atoms
• single bond = 1 sigma bond
• double bond = 1 sigma bond and 1 pi bond
• triple bond = 1 sigma bond and 2 pi bonds
• Molecular orbital theory – bonds are formed from interaction of atomic orbitals to form molecular orbitals.
• A bonding molecular orbital has lower energy and greater stability than the atomic orbitals from which it was formed.
• An antibonding molecular orbital has higher energy and lower stability than the atomic orbitals from which it was formed
• Delocalized molecular orbitals are not confined between two adjacent bonding atoms, but actually extend over three or more atoms.