1. Organic Chemistry
The study of the structure, reaction, and synthesis of compounds that consist mostly of carbon and hydrogen
Organic compounds can contain other elements, such as nitrogen, oxygen, halogens, and sulfur in smaller amounts
It is important to elucidate the structure and bonding of the atoms in organic compounds to help understand how and why they react
Carbon atoms generally bond covalently, sharing one, two, or three pairs of electrons with other atoms
To do this, they use either sp3 (tetrahedral), sp2, (trigonal planar), or sp (linear) hybridization schemes

2. sp3 Hybridization: 1 s and 3 p AOs combine to form 4 sp3 hybrids
Useful for describing tetrahedral geometry around a carbon atom
1s bond
109.5° bond angles
413 kJ/mol
1.54 Å
sp2 Hybridization: 1 s and 2 p AOs combine to form 3 sp2 hybrids
Useful for describing trigonal geometry around a carbon atom
1s bond / 1p bond
120° bond angles
614 kJ/mol
1.34 Å
sp Hybridization: 1 s and 1 p AOs combine to form 2 sp hybrids
Useful for describing linear geometry around a carbon atom
1s bond / 2p bonds
180° bond angles
839 kJ/mol
1.20 Å

3. Bonds that form between atoms with different electronegativities are polar covalent bonds
Electronegativity increases as you move up through a group and right through a period on the periodic table
C - C
DEN = 2.5 – 2.5 = 0
Non-polar
C - H
DEN = 2.5 – 2.1 = 0.4
Slightly polar
C - O
DEN = 3.5 – 2.5 = 1.0
Polar
C - F
DEN = 4.0 – 2.5 = 1.5
Very polar
If polar bonds are present in a molecule, and the molecule is asymmetric, it will be a polar molecule
Non-polar
Polar
Polar
Non-polar

4. Different interactions lead to different reaction mechanisms
Polar molecules have a separation of charge and they will interact electrostatically
Cl- H d+ C F d- H H
Molecules with regions of high electron density will behave in a similar way H+ + H H C C H H H
It is interactions like this that lead to reactivity in organic molecules
Different interactions lead to different reaction mechanisms

5. Organic molecules that contain carbon and hydrogen
Hydrocarbons
Organic molecules that contain carbon and hydrogen
Saturated Hydrocarbon
Unsaturated Hydrocarbon
Hydrocarbons are identified and named primarily by the number of carbons if their longest carbon chain
Chain length is denoted using prefixes
1 C
meth-
5 C
pent-
2 C
eth-
6 C
hex-
9 C
non-
3 C
prop-
7 C
hept-
10 C
dec-
4 C
but-
8 C
oct-

6. The type of hydrocarbon is given by the level of saturation
Alkanes
All CH bonds are single bonds
Formula: CnH2n+2
CH4
methane
C3H8
propane
C6H14
hexane
C2H6
ethane
C4H10
butane
C8H18
octane
Alkenes
Contain double bonds
Formula: CnH2n
C2H4
ethene
ethylene
C4H8
butene
butylene
C3H6
propene
propylene
C6H12
hexene
hexylene
Alkynes
Contain triple bonds
Formula: CnH2n-2
C2H2
ethyne
ethylyne
C4H6
butyne
butylyne
C3H4
propyne
propylyne
C6H10
hexyne
hexylyne

7. If there are substitutions on the longest chain, the carbons are numbered to identify the location of the substitution
Substitution =
- CH3
methyl group 1 2 3 4 5 6
CH3
CH2
Hexane
CH3 CH
CH2
2- methylhexane
CH3
CH2 CH
3- methylhexane
CH3
CH2 C
3,3 - dimethylhexane
CH3
CH2 CH
3,4 - dimethylhexane

8. For alkenes, the numbering system is used to locate the double bond(s)
1 - pentene
If there is more than one double bond, we use the term diene
1,4 - pentadiene
We can combine these rules for molecules with multiple items
2,2 – dimethyl – 3-hexene

9. When the double bond is on a middle carbon, we have to worry about which “side” of the double bond is substituted
trans -
2 - butene
cis -
2 - butene 1 8
3 –
octene 2 7 5
6 – 6
methyl 3 4
cis –
Cis - 6 – methyl – 3 - octene

10. The terminal carbons can bond to each other to make rings
Cyclic compounds
The molecules are very floppy because they can rotate around the C-C bonds
The terminal carbons can bond to each other to make rings
cyclo
hexane
This molecule is best viewed in three dimensions

11. If we make the molecule unsaturated, an aromatic compound may result
benzene
Resonance structures
There is actually overlap between all of the unhybridized p-orbitals on each sp2 carbon atom
The actual benzene molecule is a hybrid of these resonance structures, with a 50% contribution from each

12. Each carbon in the ring is sp2 hybridized so they have 3 sp2 hybrids
and one unhybridized atomic p-orbital H H H H H H
Two sp2 hybrids on each carbon overlap to form s bonds
The 3rd sp2 hybrid on each carbon overlaps with H to form a s bond
All p-orbitals overlap side-to-side to make p-bonds

13. Functional groups
Functional groups are specific groupings of atoms that are responsible for the characteristic reactivity of different compounds
The presence of different functional groups add to the naming scheme for organic molecules
There is a formal name for each molecule, but there are also common names
New and different types of substitution are possible with different groups on the carbon chains

14. Halogenated Hydrocarbons
Formula: R-X
R = organic molecule
X = halogen
Chloromethane
Bromoethane
trans-Dichloroethene
ortho -
Difluorobenzene
meta -
Difluorobenzene
para -
Difluorobenzene

15. Alcohols Formula: R-OH Methyl alcohol Methanol Ethyl alcohol Ethanol
trans - 1,2 - ethylenediol
o -Benzenediol
m -Benzenediol
p -Benzenediol
Catechol
Resorcinol
Hydroquinone

16. trans - 1,2 - dimethoxyethene
Ethers
Formula: R-O-R
Dimethyl Ether
Diethyl Ether
trans - 1,2 - dimethoxyethene
o -Dimethoxybenzene
m -Dimethoxybenzene
p -Dimethoxybenzene

17. Formula:
R – C - H O
Aldehydes
Acetaldehyde
Benzaldehyde
Formaldehyde
Formula:
R – C – R’ O
Ketones
Acetone
Methyl ethylketone
Methyl phenylketone

18. Formula:
R – C - OH O
Carboxylic Acids
Formic Acid
Acetic Acid
Benzoic Acid
Formula:
R – C – O- R’ O
Esters
Methyl Acetate
Ethyl Acetate

19. Acetic Anhydride
Salicylic Acid
Acetic Acid
Acetylsalicylic Acid