structure and bonding molecular orbital theory hybridization isomerization dipoles and polarity
TRANSCRIPT
Structure and Bonding
Molecular Orbital Theory
Hybridization
Isomerization
Dipoles and Polarity
Orbitals are ProbabilitiesMotion of Electrons Described as Wave Functions
2s Orbital Has a Node
Bonding in H2
Sigma (Bond
Wave Depiction of H2 Waves reinforce
Molecular OrbitalsMathematical Combination of Atomic Orbitals
Antibonding Molecular Orbital Destructive Overlap Creates Node
and * of H2Each Wave Function Corresponds to a
Different Energy State for an Electron
Energy Released When Bond Forms
The p Orbital
px, py, pz
Ground State Electron Configurations
Electron Configuration of Carbon
Lewis Dot Structure of Methane
C...
.
carbon - 4 valence e hydrogen - 1 valence e
H.
1s22s22p2 1s
Tetrahderal Geometry
Methane Representations
In Ground State2 bonding sites, 1 lone pair
ground state
zyx2p
2sH
HH
H
CCH4
sp3 Hybridization 4 Regions of electron Density link
4
tetrahedral geometryexcited state
hybridize
4 identical sp3 orbitalszyx2p
2s4 sigma bonds requires 4 hybrid orbitals
CH4C
H
HH
H 2s
2p x y z
ground state
sp3
Hybridization of 1 s and 3 p Orbitals – sp3
sp3 is Tetrahedral GeometryMethane
Ammonia Tetrahedral Geometry
Pyramidal Shape
All Have the Same GeometryAll Have 4 Regions of Electron Density
Orbital Depiction of Ethane, C2H6 , the bond
Bonding Characteristics of Period 2 Elements
A Saturated Hydrocarbon
sp2 Hybridization3 Regions of Electron Density
pz
H
HC
H
H
CH2=CH2
C
3 sigma bonds requires 3 hybrid orbitals
2s
2p x y z
ground state
2s
2p x y z3 identical sp2 orbitals
hybridize
excited statetrigonal planar geometry
3sp2 pz
Hybridization of 1 s and 2 p Orbitals – sp2
An sp2 Hybridized Atom
Ethylene CH2=CH2
Views of Ethylene, C2H4
Ethylene
Formaldehyde
sp Hybridization2 Regions of Electron Density
py
H C HC
pz
2 sigma bonds requires 2 hybrid orbitals
2s
2p x y z
ground state
2s
2p x y z2 identical sp orbitals
hybridize
excited statelinear geometry
2
The sp Orbital
Acetylene, C2H2, 1 bond
2 perpendicular bonds
Pauling Electronegativity Scale
Electrostatic Potential Map Cholormethane
Opposite polarity in CH3Li
Methanol
Dipole Moment () is sum of the Bond Moments
Nonpolar CompoundsBond Moments Cancel Out
Dipole Moment reflects Both Resonance Structures
C N
O
O
H
H
HHH
H
N
O
O
C
Resonance Hybrid
C
H
HH
O
O
N
NCl3 and BCl3
NClCl
Cl B
Cl
= 0
Cl Cl
N-Cl bond momentsdo not cancel N
sp3 sp2
pyramidal trigonal planar
Dipole Moments
Dipole-Dipole Interactions
London Dispersion Forces
The Effect of Branching on Boiling Point
Polar Solute in H2O
Polar Solute in Nonpolar Solvent
Nonpolar Solute in Nonpolar Solvent
Hydrogen Bonding