Organic Chemistry

Obj. 1 Bonding in Hydrocarbons Organic compounds that contain only Carbon & Hydrogen

are called Hydrocarbons. Carbon-hydrogen bonding Carbon has 4 valence e- and will “always form 4 covalent bonds”

EXAMPLE: Methane H | H – C – H | H

Carbon – Carbon bonding

Forms a covalent bond between carbons and covalent bonds with the Hydrogens also.

EXAMPLE: Ethane - C2H6

H H | | C - C H – C – C – H | | skeletal formula H H ( C __ H bond Structural Formula understood )

Obj. 2 Straight chained and branched alkanes

Alkanes- contain only single covalent bonds

Straight chain alkanes contain any number of carbon atoms, one after another in a chain.

Straight chain alkanes end in -ane

Methane H Ethane H H I I I H – C – H H – C – C – H I I I H H H

Propane H H H Butane H H H H I I I I I I I H – C – C – C – H H – C – C – C – C – H I I I I I I I H H H H H H H

Pentane H H H H H I I I I I H – C – C – C – C – C – H I I I I I H H H H H

Hexane H H H H H H I I I I I I H – C – C – C – C – C – C – H I I I I I I H H H H H H

Branched chain alkanes Halogens, carbon, hydrogen, oxygen, nitrogen, sulfur and

phosphorus atoms may take the place of a hydrogen in an alkane.

These atoms, or group of atoms, that take the place of hydrogen atoms on a parent (or base) hydrocarbon molecule are called substituents.

The substituent is called an alkyl group. When an alkyl group is added to a straight chain

hydrocarbon, branches form. An alkane with one or more alkyl groups is a

branched-chain alkane C C C C

| | | | C __ C – C C __ C – C – C – C – C Parent chain (propane) Parent chain (hexane)

Obj. 3 Saturated and unsaturated hydrocarbons

Saturated hydrocarbons – alkanes which contain the maximum number of hydrogens.

H H HI I I

H – C – C – C – H I I I H H H

Unsaturated hydrocarbons – organic compounds that contain double or triple carbon – carbon bonds and have less than the maximum number of hydrogens. H

IH – C – H

IH – C – C = C – H

I I H H

Obj. 4 Alkanes and AlkynesAlkanes – contain carbon – carbon double covalent bonds.(share 2 e- from each carbon)H H \ / C =C / \H H

Alkynes – contain carbon – carbon triple bonds.(share 3 e- from each carbon)

- C C -

Obj. 5 Naming, Writing, and Drawing molecular formulas. 7 6 5 4 3 2 1 CH3 – CH2 – CH2 – CH2 – CH – CH – CH3 I I I CH2 CH3 CH3

I CH3

Rules for naming molecular formulas

1.Find the longest chain of carbons in the molecule. This chain is the parent chain.[(ends in – ane)The example is heptane]

2. Number the carbons in the main chain in sequence. Start at the end that will give the groups attached to the chain the lowest numbers.

3.Add numbers to the names of the substituent groups to identify their positions on the chain. These numbers become prefixes to the name of the parent chain.

4.Use prefixes to indicate the appearance of a group more than once in the structure. (example- 2-methyl,3-methyl, 4-ethyl)

5.List the names of alkyl substituents in alphabetical order. For purposes of alphabetizing, ignore the prefixes di-, tri-, etc.(example - Two methyls = dimethyl)

6. Use proper punctuation. Commas are used to separate numbers. Hyphens are used to separate numbers and words. (The entire name is written without any spaces.)

Example above: 4-ethyl-2,3-dimethylheptane

Obj. 5 Name and Write Hydrocarbons (Worksheet)

Obj. 6 Common cyclic rings and aromaticsCyclic rings- when the two ends of a carbon chain are attached to form a ring

C

C

C

H

H

H

H

HH

Cyclopropane

Cyclobutane

C HC

C C

HH

H

H

HH

H

C

C C

CC

HH

H

H

HH

HH

HH

Cyclopentane

C

C

C C

C

C

H

H

H

HH

H

HH H

H

H

H

Cyclohexane

CC

C

C

C

C C

H

HH

H

HH

H

HH

H

HH

H H

Cycloheptane

Aromatic compounds – a special group of unsaturated cyclic rings (can contain a single ring or a group of rings)

EXAMPLE: Benzene:

Obj. 7 Uses of organic compounds

Fossil Fuels – organic because they are derived from the decay of organisms in geologic history

Example:Petroleum, natural gas, coal,Used as lubricants , burning processes for energy (to make electricity and cooking food)

H

H

H

H

H

H

Single Bond

Plastics – created by the process of addition polymerization and condensation polymerization of hydrocarbons (see Obj. 8)Examples: used for innumerable objects- laminates, bags, pipes, handles, cars…

Medicines – created by halogen and cyclic ring substitution reactions Examples:produce drugs, pain killers and other functional groups(see Obj 10).

Obj. 8 &9 Monomers and PolymersPolymers- A large molecule formed by the covalent bonding of repeating smaller molecules.Monomers- Smaller molecules that combine to form a polymer.

C CHH

H Hx

X is the number of ethylene units that combine to form long chains

H ( CH2 CH2 )x H

X is the number of repeating CH2 CH2 units in a polymer; parentheses identify the repeating unit

Addition Polymers- form when unsaturated monomers react and form a polymer.

Polyethelene - plastic milk bottles, plastic wraps, refrigerator dishesPolypropylene – utensils and containersPolystyrene – styrofoam cups and insulation of coolers.Polyvinyl chloride – (PVC) pipes in plumbingTetra flourethene – (PTFE) teflon coatingPolyisoprene –natural rubber - boots, tires, tubing

Condensation Polymers - formed by the head to tail joining of monomer units This is usually accompanied by the loss of water

from the reacting monomers and the formation of water as a product: thus condensation

Examples:Polyesters – tire cords, permanent press clothing, magnetic tape in tape recorders.Polyamides –

Nylon-carpeting, tire cords, fishing line, sheer hosiery, gears and zippers.Kevlar- bullet proof vests.

Obj. 10 Functional groups

Functional Group – specific arrangement of atoms in an organic compound that is capable of characteristic chemical reactions.

Symbol “R” in each functional group represents any carbon chains or rings attached to the functional group.

Alcohol –organic compound with an -OH groupEsthers – oxygen bonded to two carbon groups. R-O-RAldehydes – carbonyl group (carbon and oxygen double bonded) and at least one hydrogen R-C-H-0Ketones- organic compounds with the carbon of the carbonyl joined to two other carbons RCORCarboxylic acid- contain a carboxyl group (carbonyl group and hydroxyl group) R-COOHEsters – contain a carbonyl group and an ether link to the carbonyl carbon. R-COORAmines- organic compound in which a nitrogen is bound to alkyle groups and hydrogen atoms [derived from ammonia (NH3)] R-NH2

Organic Compounds Classified by Functional Groups Compound Type Compound Structure Functional Group

Alcohol

Ether

Aldehyde

Ketone

Carboxylic acid

Ester

Amine

R – OH

R – O – R

OII

R – C – H

OII

R – C – R

OII

R – C – OH

OII

R – C – O – R

R—NH2

Hydroxyl

Ether

Carbonyl

Carbonyl

Carbonyl

Ester

Amino