what are the building blocks? carbon hydrogen oxygen nitrogen phosphorus chlorine atoms methane...
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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
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