Organic ChemistryChemistry 2013-2014

Carbon can form 4 covalent bonds with other atoms. This allows it to make millions of different compounds.

Carbon can form single, double and triple bonds.

Organic chemistry is the chemistry of carbon compounds

Saturated hydrocarbons contain no double or triple bonds.

Unsaturated hydrocarbons contain double and/or triple bonds.

Can be straight or branched. Boiling point increases as

number of carbon atoms increases.

A hydrocarbon is a compound that only contains hydrogen and carbon atoms.

Definition/Functional group: single bonds only; saturated; nonpolar

Suffix: -aneExamples

Methane Ethane

Hydrocarbons: Alkanes

Definition/Functional group: at least one double bond; unsaturated; nonpolar

Suffix: -eneExample: ethene, C2H4

Hydrocarbons: Alkenes

Definition/Functional group: at least one triple bond; unsaturated; nonpolar

Suffix: -yneExamples

Ethyne, C2H2 Butyne, C4H6

Hydrocarbons: Alkynes

Definition/Functional group: contain at least one benzene ring, often with other groups added (“substituted” for hydrogen). Benzene exists as a resonance structure. It is also a carcinogen.

Prefix: Benz- Examples

Benzene Benzaldehyde

Benzene Rings

Definition/Functional group: contain an –OH group, called a “hydroxyl” group.

Suffix: -ol Examples

Methanol Ethanol Propanol

AlcoholsNote: not all alcohols are safe to drink (ethanol is the “alcohol” in all alcoholic beverages). The “alcohol” family is large and its members have many properties. For example, methanol is highly toxic!

Definition/Functional group: contain an oxygen atom double-bonded to a carbon atom at the end of a hydrocarbon chain.

Suffix: -anal Examples: Methanal, CH2O Ethanal,

C2H4O

Aldehydes

Definition/Functional group: contain an oxygen atom double-bonded to a carbon atom NOT at the end of a hydrocarbon chain.

Suffix: -none Examples

Propanone, C3H6O

Ketones

Definition/Functional group: a hydrocarbon chain in which one of the links is an oxygen atom, bonded to a carbon atom on either side.

Suffix: -ether Examples

Ethers

Definition/Functional group: a hydrocarbon where one carbon atom is bonded to another carbon and two oxygen atoms, one through a single bond and one through a double bond. That sounds pretty confusing, but esters are easy to recognize. They all have the same basic shape as the picture above, where the letter “R” means carbon atoms or other “organic” groups.

Suffix: -ate Examples

Esters

Definition/Functional group: these are alkanes that are cyclic, meaning that the ends are connected to form a regular geometric shape. Ex. triangle, square, pentagon, hexagon, etc. Benzene is not a cyclic alkane due to its double bonds and resonance.

Prefix: Cyclo- Examples: Cyclopropane, C3H6 Cyclobutane, C4H8

Cyclic Alkanes

We’re going to focus on naming the simplest kinds of organic molecules—alkanes, alkenes, alkynes, alcohols, and aldehydes.

However, you will have to be able to classify the names and structures of each type of organic molecule in these notes, or to pick a name from a list that most closely fits a structure.

Nomenclature

Prefixes (stand for number of carbon atoms in chain):

Number of Carbon Atoms Prefix Number of

Carbon Atoms Prefix

1 Meth- 6 Hex-

2 Eth-  7 Hept-

3 Prop- 8 Oct-

4 But- 9 Non-

5 Pent- 10 Dec-

What type of organic molecules are these prefixes and suffixes used for?

AlcoholEsterKetone

AlkeneBenzene ringAlkane

What kind of prefix or suffix matches each of these structures?

-yne -none

Cycl0--ane -ane Benz-

To determine the name of an organic molecule, first classify it by type. Then count the number of carbon atoms in the molecule.

For example, the following structure has one double bond, so its suffix is –ene. There are six carbon atoms in the chain, so its root is hex-. The name of this structure is hexene.

Structure Prefix Root Suffix Name

       

       

       

Prop- -ene Propene

Cyclo- -hept- -ane Cycloheptane

Pent- -yne Pentyne

Structure Prefix Root Suffix Name

       Prop- -anal Propanal

Pent- -ol Pentanol

Propanol Cyclobutane PentanalDraw the following: