The Chemistry of Carbon Organic Chemistry The Chemistry of Carbon

Topics Standard Representation “Straight” Chain Alkanes Alkyl Groups Naming Substituted Hydrocarbons Determining the Structure from a name Structural Isomers Basic Functional Groups

Representing Organic Molecules Hydrocarbons are compounds containing only Carbon and Hydrogen and oxygen. The simplest Hydrocarbons are the “Straight” Chain Alkanes The 3 Standard methods of representing Hydrocarbons are: H H H H | | | | H-C-C-C-C-H or CH3-CH2-CH2-CH3 or C4H10 H H H H Condensed Structure Molecular Formula Full Structure

Naming “Straight” Chain Alkanes # of Carbon Name Condensed Formula methane = CH4 1 ethane =CH3-CH3 2 propane=CH3-CH2-CH3 3 butane=CH3-CH2-CH2-CH3 4 pentane = CH3-CH2-CH2-CH2-CH3 5 hexane= 6 heptane= 7 octane= 8 nonane= 9 decane= 10

Branched Alkanes A Hydrocarbon chain can have “side branches” which are also hydrocarbon chains CH3-CH2-CH-CH2-CH3 | CH2 (alkyl group) CH3

Naming Alkyl groups Replace “ane” with “yl” methane (CH4) Becomes Methyl (CH3-) ethane (CH3-CH3) => ethyl (CH3-CH2-) propane =>propyl butane=>butyl pentane => pentyl Etc.

Naming Substituted Hydrocarbons A Substituted hydrocarbon is named by writing the following one after another: The carbon number at which the alkyl group is found A dash, The name of the alkyl group, and finally The name of the longest “parent” carbon chain NOTE: the carbon atoms in the parent are numbered consecutively From one end in a manner the give s the LOWEST POSSIBLE SET OF NUMBERS to the attached groups *****

Naming Substituted Hydrocarbons If more than one DIFFERENT alkyl group is attached to a hydrocarbon: List the alkyl groups alphabetically, Precede each alkyl group by its number Put a dash between number and name.

Naming Substituted Hydrocarbons if an alkyl group is repeated, then List each carbon number where the repeated group is attached separated by comas Prefix the repeated group name by di, tri, tetra, etc, to show how many identical groups are attached

Cycloalkanes Hydrocarbons chains that connect “head to tail” are called cyclic, and you use the prefix “cyclo” when naming them Examples

Naming Alkyl Halides Naming of alkyl halides (halogens F,Cl, Br, I) attached to Alkanes is just like alkyl groups attached to an alkanes, but we use the names “Flouro, Chloro,Bromo,Iodo” instead. Examples

Alkenes and Alynes An alkene is an organic molecule containing a carbon-carbon double bond CH3-CH=CH-CH3 An alkyne is an organic molecule containing a carbon-carbon triple bond. Example

Naming Alkenes Count the carbon chain so that the double bond has the lowest number. Replace the “ane” ending of the parent with “ene” Examples

Naming Alkynes Count the carbon chain so that the triple bond has the lowest number. Replace the “ane” ending of the parent with “yne” Examples

Structural Isomers Compounds that have the same molecular formula but different arrangement of atoms are called structural Isomers Example what are the Structural Isomers of C5H14

Geometircal Iosmers (Cis and Trans Isomers) For alkenes and alkynes 2 new types of structural isomers are possible due to the rigidity of the double and triple bonds. For “CIS” isomers the groups are on the same side of the double/triple bond For “Trans” isomers the groups are on the opposite side of the double/triple bond