Mullis 1

Petrochemicals• Petrochemicals are compounds produced from

oil or natural gas.

• Most are used to produce other synthetic products, especially plastics.

• Builder molecules are those small-molecule compounds such as ethene.

• Ethene is a 2-carbon hydrocarbon with a double bond (2 pairs of shared electrons).

• Compounds with double and triple bonds are more reactive than those with single bonds.

Mullis 2

Addition Reactions• Water adds to ethene: The double bond is broken and

an H attaches to one carbon and the OH attaches to the other carbon.

H H H H

C C + H-OH H-C-C-H

H H H H• Ethene can add to itself, breaking double bonds to

attach to one molecule after another.

• A monomer is a small unit; when additional monomers are attached repeatedly, a long-chain polymer is formed.

Mullis 3

Addition Polymers• Polyethylene is a polymer made from the monomer

ethene. Zip-lock bags are usually made from low-density polyethylene.

• Common polymer variations replace one of ethene’s hydrogens with another unit, such as a halogen atom (F or Cl), Cyanide (CN), or benzene (C6H6).

– Vinyl chloride polyvinyl chloride– Acrylonitrile polyacrylnitrile– Styrene polystyrene

• Atoms that compose the monomers determine the properties of the polymer.

Mullis 4

HydrocarbonsUnsaturated hydrocarbons

– Double and triple bonds between carbons

– Not every carbon has each of its 4 electrons bonded to 4 different atoms

– More chemically reactive than saturated compounds, or alkanes

– Unsaturated hydrocarbons include alkenes (double bonds) and alkynes (triple bonds)

Mullis 5

Cyclic Compounds

• Cycloalkanes – Saturated carbons joined in a ring

– Example is cyclohexane, C6H12

• Aromatic compounds– Unsaturated: Contains 3 double bonds

– Example is benzene, C6H6

C-H

C-H

C-H

H-C

H-C

H-C

Mullis 6

Naming Organic Compounds1. Name the parent hydrocarbon: Use the

LONGEST STRAIGHT chain of carbon atoms.2. Add the name of the alkyl groups attached to the

chain. If more than one group is attached, use the proper numerical prefix to indicate how many groups are attached. (2=di, 3-tri,etc.)

3. Assign numbers to the carbons in the parent chain. Assign so that attached groups are at the lowest number possible.

4. Insert the numbers in front of the proper group.5. Separate position numbers from names with

hyphens.

Mullis 7

Example: Naming Organic Compounds1. Name the parent hydrocarbon.

CH3 – CH – CH2 – CH – CH – CH3 hexane

CH3 CH3 CH3

2. Add the name of the alkyl groups attached to the chain. 3 methyl groups: trimethylhexane 3. Assign numbers to the carbons in the parent chain.6 5 4 3 2 1

CH3 – CH – CH2 – CH – CH – CH3

CH3 CH3 CH3

4-5. Insert position numbers and add hyphens.2,3,5-trimethylhexane

Mullis 8

Name the following compounds1. CH3 – CH – CH2 – CH2 – CH3

CH3

2. CH3 – CH – CH2 – CH2 – CH – CH3

| |

CH3 CH3

3. CH3 – CH – CH2 – CH2 – CH3

CH2

CH2

Mullis 9

Unsaturated hydrocarbons

• Single bond between carbons: -ane ethane H3-C C-H3 CnH2n+1

• Double bond between carbons: -ene ethene H2-C C-H2 CnH2n

• Triple bond between carbons: -yne ethyne H-C C-H CnHn

• Locate the longest continuous chain containing a double bond. If there is only one double bond, add the suffix –ene to the proper prefix for this number of carbons.

• Add the names of alkyl groups as in single-bond compounds, EXCEPT: Number the carbons so that the 1st C in the double bond is nearest the end that has the lowest number.

• Place the position number of alkyl groups before proper group, and place position number for the double bond before the alkene name.

• Alkynes are named similarly, except all references to a double bond becomes a triple bond, and –ene becomes –yne.

• Example: 2-ethyl-3-methyl-1-butene CH3

| CH3 –CH--C==CH2

| CH2--CH3

Mullis 10

Naming Organic Compounds: Beyond saturated hydrocarbons

• Cyclic compounds• Add cyclo- to beginning of name if the alkane is known to

be arranged in a circle (CnH2n). No position number is needed if only one alkyl group is attached.

• Aromatic hydrocarbon, or benzene (C6H6: Electron orbitals overlap to form continuous orbitals = delocalized electrons throughout the ring.)

• Assign position number 1 to the alkyl group that comes first in alphabetical order, then number in the direction to give the rest of alkyl groups the lowest number possible.

• Example: 1-ethyl-4-methylbenzene• CH3-CH2- -CH3

Mullis 11

Functional Groups(R = rest of molecule, usually C and H) atoms)

Compound Formula Example Alcohol R-OH hydroxyl group 1-propanol Alkyl Halide -X X = any halide 1,2-dibromopropane Ether R-O-R’ one oxygen bonded to 2

hydrocarbon groups diethyl ether CH3-CH2 –O--CH2--CH3

Aldehyde O || R-C-H

Carbonyl group attached to end carbon

Ethanal O || CH3—C--H

Ketone O || R-C-R’

Carbonyl group attached to a middle carbon

2-propanone O || CH3—C-- CH3

Carboxylic Acid O || R-C-OH

Carboxyl group ethanoic acid O || CH3—C—OH

Ester O || R-C-O-R’

Carboxyl group without the H

methyl ethanoate O || CH3—C—O-- CH3