Review for Organic II
Valance Shell
• The Valance Shell is the outermost shell which contains at least one electron.
• In this example the 2s is the valance shell.
Nucleus
Valence Shell = 2s
1s
2s
1s Orbital
= Nucleus
= 1s Orbital
p Orbitalsy
x
z
y
x
z
= 2py Orbital
y
x
z
= 2pz Orbital
y
x
z
= 2px Orbital
sp3 Orbitals of Carbon (C)
1s
2s
2p
Normal
1s
2s
sp3 orbitals
2psp3
H
CH H
H
• Normally you have 1s orbital and 3p orbitals. However in the case of Carbon (C) the S and P orbitals merge to form the sp3 orbitals.
What is Electronegativity?
• Electronegativity is the desire of an atom to gain an additional electron to fill its octet or the strength of the atom to pull electrons.
• The higher number the stronger the electronegativity.– Largest electronegativity: F = 4.0, Cl = 3.5,
O = 3.5, N = 3.0, Br = 2.8, C = 2.5
Ionic Bonds
• Ionic Bonds are where an electron is donated to another atom. This creates two charged species. These charged atoms or molecules are normally free in solution but are held together when solid by electrostatic attractions.
Na + Cl Na+ + Cl-
gives up an electron
gains an electron
Na+
Na+
Na+
Cl-
Cl-Cl-
Solution Solid -crystals
Na+Cl- Na+
Cl- Na+Cl-
Covalent Bond
• Describes the sharing of electrons between two atoms. There are two different types of covalent bonds.– Nonpolar covalent bonds is defined as the even
distribution of electrons between 2 atoms.– Polar covalent bonds is defined as the uneven
distribution of electrons between two atoms.
Polar Covalent Bonds
• Describes the unequal sharing of electrons in a covalent bond.
C
O
R R
Electrons are around the oxygen 70%of the time Electrons are around the carbon 30%
of the time
• This makes the oxygen considered partially negative because the electrons around it more. The carbon is considered partially positive because the shared electrons are mainly around the oxygen.
Basic Carbon Structures: Carbon
Family Name Functional Group Simple Example Name Ending
Alkane -ane
Alkene
-ene
Alkyne
-yne
Arene
-none
C C
C C
C C
C CC
CCC
C C
H
H
H
H
HH
Ethane
Benzene
H
H
H
H
Ethene
C C HHEthyne
Naming Carbons Skeletons• 1 (Carbon) Meth-• 2 (Carbons) Eth-• 3 (Carbons) Prop-• 4 (Carbons) But- • 5 (Carbons) Pent-• 6 (Carbons) Hex-• 7 (Carbons) Hept-• 8 (Carbons) Oct-• 9 (Carbons) Non-• 10 (Carbons) Dec-
C
H
H
H H
C C
H H
H
H
H
H
C C
H H
H
H
H
C
H
H
H
C C
H H
H
H
H
C
H
H
C
H
H
H
C C
H H
H
H
H
C
H
H
C
H
C
H
H
H
H
C C
H H
H
H
H
C
H
H
C
H
C
H
H
C
H
H
H
H
C C
H H
H
H
H
C
H
H
C
H
C
H
H
C
H
H
C
H
H
H
H
C C
H H
H
H
H
C
H
H
C
H
C
H
H
C
H
H
C
H
H
C
H
H
H
H
C C
H H
H
H
H
C
H
H
C
H
C
H
H
C
H
H
C
H
H
C
H
H
H
C
H
H
H
C C
H H
H
H
H
C
H
H
C
H
C
H
H
C
H
H
C
H
H
C
H
H
H
C
H
H
C
H
H
H
Methane
Ethane
Propane
Butane
Pentane
Hexane
Heptane
Octane
Nonane
Decane
Basic Carbon Structures: Oxygen
Family Name Functional Group Simple Example Name Ending
Alcohol-ol
Ether -ether
Phosphate None None
C O H
C O C
C C
H
H
O H
H
H
H
Ethanol
C O P
O
O
O
C O C H
H
H
H
Methyl Ether
H
H
Basic Carbon Structures: Carboxyl
Family Name Functional Group Simple Example Name Ending
Carboxyl
Aldehyde -al
Ketone -one
Carboxylic acid -oic acid
Ester -oate
Carboxylic acid anydride
-oic anhydride
C
O
C C
O
H
C C
O
C
C C
O
O H
C C
O
O C
C C
O
O C
O
C
H C
H
H
C
O
O H
Acetic Acid
Basic Carbon Structures: Nitrogen
Family Name Functional Group Simple Example Name Ending
Amine -amine
Nitrile -nitrile
Nitro -none
Amide -amide
C N
C C N
C NO
O
C C
O
N
Basic Carbon Structures: Sulfur
Family Name Functional Group Simple Example Name Ending
Sulfide sulfide
Sulfoxide sulfoxide
Sulfonesulfone
Thiol -thiol
C S C
C S
O
C
C S
O
C
O
C S H
Common Functional GroupsFamily Name Functional Group Simple Example Name Ending
Ether -ether
Amine
-amine
Carboxyl -
Arene
-noneC C
CCC
C
C O C
C N
C
O
Kinds of Reactions
• Addition Reactions
• Elimination Reactions
• Substitution Reactions
• Rearrangement Reactions
Unsymmetrical Bond Breaking
• Unsymmetrical bond breaking - split bonds and gives both electrons to one atom. The most electronegative atom receives the both electrons.
A B A B+ -+
Symmetrical Bond Breaking
• Symmetrical bond breaking - split bonds and gives an electron to both atoms. The normally occurs when the electronegativity of the bond is the same.
A B A B+
Transitional State• The transitional state represents the
highest energy structure in this step of the reaction.
Reactions of Alkenes
C C
OHH
Alcohol
HH
OHHO
1,2-Diol
O
CO
XH
XX
OHX
Alkane
Carbonyl Compound
CyclopropaneEpoxide
1,2-Dihalide
Halide
Halohydrin
alkene
Chirality• If an object has a plane of symmetry it
is necessarily the same as its mirror image
• The lack of a plane of symmetry is called “handedness”, chirality
• Hands, gloves are prime examples of chiral object–They have a “left” and a “right” version
HO-
H3C
H
H3CH2C
BrHO
H CH3
CH2CH3
Br
H3C
H
H3CH2C
Br
(S)-2Bromobutane Transition State
+HO-
CH3
H
CH2CH3
HO
(R)-2-Butanol
+ Br-
The SN2 Reaction
Stereochemistry of SN1 Reaction
• The planar intermediate should lead to loss of chirality– A free
carbocation is achiral
• Product should be racemic
Basic Carbon Structures: Alkane
C C
Basic Carbon Structure: Alkene
C C
Basic Carbon Structure: Alkyne
C C
Basic Carbon Structure: Alcohol
C O H
Basic Carbon Structure: Ether
C O C
Basic Carbon Structure: Carboxyl
• Carboxyl is found in a number of functional groups.
• It is reactive and is often used in organic reactions.
C
O
Basic Carbon Structure: Aldehyde
C C
O
H
Basic Carbon Structure: Ketone
C C
O
C
Basic Carbon Structure: Carboxylic Acid
C C
O
O H
Basic Carbon Structure: Ester
C C
O
O C
Basic Carbon Structure: Amine
C N
Basic Carbon Structure: Imine
C C N
Basic Carbon Structure: Nitrile
C C N
Basic Carbon Structure: Nitro
C NO
O
Basic Carbon Structure: Amide
C C
O
N
Basic Carbon Structure: Sulfide
C S C
Basic Carbon Structure: Sulfoxide
C S
O
C
Basic Carbon Structure: Sulfone
C S
O
C
O
Basic Carbon Structure: Thiol
C S H