what are the building blocks? carbon hydrogen oxygen nitrogen phosphorus chlorine atoms methane...
TRANSCRIPT
What are the building blocks?
Carbon
Hydrogen
Oxygen
Nitrogen
Phosphorus
Chlorine
Atoms
Methane
Formaldehyde
Hydrogen cyanide
Phosphorus pentachloride
Molecules
Subatomic particles Protons
Electrons
• s orbital
• p orbital
• d orbital
• Hybrids
It’s all aboutbuilding blocks
4 3 2 1
Carbon Nitrogen Oxygen Hydrogen
Number of available connections (bonds)
HH HHCC
HH Methane
HH
HHCC
HHMethanol
HHOO
HH
The forces at work are:
Electromagnetic:
Repulsion of like charges: proton-proton and electron-electron
Attraction of unlike charges: proton-electron.
Magnetic:
Electron spin introduces magnetic forces. Electrons with opposite spins produce opposite magnetic poles. Opposite magnetic poles attract. Opposite spin is required for electrons to occupy the same orbital.
Lewis Structures & Molecular Shape
Lewis Structures
Gilbert Lewis
Lewis Structures
• Keeps track of valence (bonding) electrons
• Predicts formula for many compounds
• Predicts charge of compounds
• Predicts stability of compounds
• Predicts molecular shape if combined with other theories.
nitrate=NO3-
Why interest in Molecular Shape?
• Predicts polar compounds (ones with ends with opposite charges)
• Predicts solubility
• Predicts interaction with light (link)
• Predicts crystal structure
δ-
δ-δ-δ+
δ-
δ-δ- δ+
Methane building blocks
Carbon
1s2 2s2 2p2
2s 2px 2pz2py1s sp3 sp3 sp3 sp3
109.5o
Promote Hybridize
x
z
y
Methane: Carbon
VSEPR
• http://www.chem.purdue.edu/gchelp/vsepr/
• http://www.shef.ac.uk/chemistry/chemputer/vsepr.html
• http://www.chemistry.wustl.edu/~edudev/Vsepr/table1.html
• http://intro.chem.okstate.edu/1314F00/Lecture/Chapter10/VSEPR.html
Orbitals
• http://www.mpcfaculty.net/ron_rinehart/orbitals.htm
Lewis Structures
• http://www.stolaf.edu/depts/chemistry/courses/toolkits/121/js/lewis/
1
2
3
4
5
PF3 5 + 7x3 = 26 valence electrons
4 groups of electrons, which will repel each other.
1s2 2s2 2p6 3s2 3p3
PF3
FP
FF
4 groups of electrons, which will repel each other.
1 central atom=A
3 bonding atoms = B3
1 non-bonding pairs of electrons = N
AB3N
AB3N
AB3N
HybridizationNumber of
electron groupsHybridization
2 sp
3 sp2
4 sp3
5 sp3d
6 sp3d2
F
Polar?
FP
F
P = 2.1
F = 4.0Electronegativity
δ-
δ-δ-
δ+
1
2
3
4
5
SCl2 6 + 7x3 = 27 valence electrons
4 groups of electrons, which will repel each other.
4 groups of electrons, which will repel each other.
1 central atom=A
2 bonding atoms = B2
2 non-bonding pairs of electrons = N2
AB2N2
AB2N2
HybridizationNumber of
electron groupsHybridization
2 sp
3 sp2
4 sp3
5 sp3d
6 sp3d2
Polar ?
δ-δ-
δ+
S = 2.5
Cl = 3.0Electronegativity
1
2
3
4
5
CS2 4 + 6x2 = 16 valence electrons
2 groups of electrons, which will repel each other.
2 groups of electrons, which will repel each other.
1 central atom=A
2 bonding atoms = B2
Zero non-bonding pairs of electrons
AB2
VESPR Sketch
AB2
Hybridization# of electron
groups Hybridization Electron geometry
2 sp
3 sp2
4 sp3
5 sp3d
6 sp3d2
for carbon
for sulfur
Straight
Trigonal
Tetrahedral
Trigonal bipyramidal
Octahedral
2s 2px 2pz2py1s sp spPromoted Hybridized
Carbon in hydrogen cyanide or carbon disulfide:
2s + 2px
Linear
Polar ?
S = 2.5
C = 2.5Electronegativity
1
2
3
4
5
KrF2 8 + 7x2 = 22 valence electrons
5 groups of electrons, which will repel each other.
5 groups of electrons, which will repel each other.
1 central atom=A
2 bonding atoms = B2
3 non-bonding pairs of electrons
AB2N3
VESPR Sketch
AB2N3
Polar ? No
Kr = 3.0
F = 4.0Electronegativity
δ-δ-
δ+
1
2
3
4
5
PO33- 5 + 6x3 + 3 = 26
valence electrons
4 groups of electrons, which will repel each other.
--
-
3-
3-
2 groups of electrons, which will repel each other.
1 central atom=A
3 bonding atoms = B3
1 non-bonding pairs of electrons=N
AB2N
VESPR Sketch
3-
3-
Hybridization# of electron
groups Hybridization Electron geometry
2 sp
3 sp2
4 sp3
5 sp3d
6 sp3d2
for P & O
Straight
Trigonal
Tetrahedral
Trigonal bipyramidal
Octahedral
3-
Trigonal pyramidal
Polar ?
O = 3.5
P = 2.1Electronegativity
δ-δ-
δ+3-
δ-
Now it’s your turn
3s 3px 3pz3py2
Neon
120o
Hybridized
Phosphorus Pentachloride: Phosphorus
TrigonalBipyrimidal
sp3d sp3d sp3d sp3d sp3d
dxz dyz dxy dx2-y2 dz2
120o
90o
Promoted
1s2 2s2 2p6 3s2 3p3
PF3
n=1l=0m=0
n=1l=0
m=0n=2l=0m=0
n=2l=0
m=0
n=2l=1m=-1
n=2l=1m=-0
n=2l=1m=+1
n=2l=1
m=-1
n=2l=1
m=0
n=2l=1
m=+1
n=3l=0m=0
n=3l=0
m=0
n=3l=1m=-1
n=3l=1m=0
n=3l=1m=+1
n=3l=1
m=-1
n=3l=1
m=0
n=3l=1
m=+1
n=4l=0m=0
n=4l=0
m=0
n=3l=2m=-2
n=3l=2m=-1
n=3l=2m=0
n=3l=2m=+1
n=3l=2m=+2
n=3l=2
m=-2
n=3l=2
m=-1
n=3l=2
m=0
n=3l=2
m=+1
n=3l=2
m=+2
n=4l=1m=-1
n=4l=1m=0
n=4l=1m=+1
n=4l=1
m=-1
n=4l=1
m=0
n=4l=1
m=+1
n=5l=0m=0
n=5l=0
m=0
n=4l=2m=-2
n=4l=2m=-1
n=4l=2m=0
n=4l=2m=+1
n=4l=2m=+2
n=4l=2
m=-2
n=4l=2
m=-1
n=4l=2
m=0
n=4l=2
m=+1
n=4l=2
m=+2
n=5l=1m=-1
n=5l=1m=0
n=5l=1m=+1
n=5l=1
m=-1
n=5l=1
m=0
n=5l=1
m=+1
n=6l=0m=0
n=6l=0
m=0
n=5l=2m=-2
n=5l=2m=-1
n=5l=2m=0
n=5l=2m=+1
n=5l=2m=+2
n=5l=2
m=-2
n=5l=2
m=-1
n=5l=2
m=0
n=5l=2
m=+1
n=5l=2
m=+2
n=6l=1m=-1
n=6l=1m=0
n=6l=1m=+1
n=6l=1
m=-1
n=6l=1
m=0
n=6l=1
m=+1
n=7l=0m=0
n=7l=0
m=0
n=6l=2m=-2
n=6l=2m=-1
n=6l=2m=0
n=6l=2m=+1
n=6l=2m=+2
n=6l=2
m=-2
n=6l=2
m=-1
n=6l=2
m=0
n=6l=2
m=+1
n=6l=2
m=+2
n=7l=1m=-1
n=7l=1m=0
n=7l=1m=+1
n=7l=1
m=-1
n=7l=1
m=0
n=7l=1
m=+1
n=4l=3m=-3
n=4l=3m=-2
n=4l=3m=-1
n=4l=3m=0
n=4l=3m=+1
n=4l=3m=+2
n=4l=3m=+3
n=4l=3
m=-3
n=4l=3
m=-2
n=4l=3
m=-1
n=4l=3
m=0
n=4l=3
m=+1
n=4l=3
m=+2
n=4l=3
m=+3n=5l=3m=-3
n=5l=3m=-2
n=5l=3m=-1
n=5l=3m=0
n=5l=3m=+1
n=5l=3m=+2
n=5l=3m=+3
n=5l=3
m=-3
n=5l=3
m=-2
n=5l=3
m=-1
n=5l=3
m=0
n=5l=3
m=+1
n=5l=3
m=+2
n=5l=3
m=+3
Period 1
Period 2
Period 3
Period 4
Period 5
Period 6
Period 7
Principle number
n l=0l=0 l=1l=1
l=2l=2
l=3l=3
HePeriod 1
Period 2
Period 3
Period 4
Period 5
Period 6
Period 7