Organic Chemistry Chemistry 2013-2014
Organic chemistryis the chemistry of carboncompounds • 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. Saturatedhydrocarbons 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: singlebonds 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 triplebond; unsaturated; nonpolar • Suffix: -yne • Examples • Ethyne, C2H2Butyne, 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- or phenyl- • Examples • BenzeneBenzaldehyde
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! Alcohols • 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, C3H6Cyclobutane, 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.
What type of organic molecules are these prefixes and suffixes used for?
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.
Draw the following: PropanolCyclobutanePentanal