Organic Chemistry Chemistry 2013-2014

Organic chemistry is the chemistry of carbon compounds 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.

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

Hydrocarbons: Alkanes Definition/Functional group: single bonds only; saturated; nonpolar Suffix: -ane Examples Methane Ethane

Hydrocarbons: Alkenes Definition/Functional group: at least one double bond; unsaturated; nonpolar Suffix: -ene Example: ethene, C2H4

Hydrocarbons: Alkynes Definition/Functional group: at least one triple bond; unsaturated; nonpolar Suffix: -yne Examples Ethyne, C2H2 Butyne, C4H6

Benzene Rings 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

Alcohols Note: 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 –OH group, called a “hydroxyl” group. Suffix: -ol Examples Methanol Ethanol Propanol

Aldehydes 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

Ketones 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

Ethers 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

Esters 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

Cyclic Alkanes 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

Nomenclature 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.

Prefixes (stand for number of carbon atoms in chain): 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? Alcohol Alkene Ester Benzene ring Ketone Alkane

What kind of prefix or suffix matches each of these structures? -none -yne 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 Pentanal Draw the following: Propanol Cyclobutane Pentanal