Isomers & Functional Groups Organic Chemistry

Organic Chemistry 2 Isomers: Compounds that have the same ____________________________ but different ___________________

Organic Chemistry 3 What are isomers? Isomers are molecules that have the same molecular formula, but have a different arrangement of the _______________________________________ That excludes any different arrangements which are simply due to the molecule _________________________, or rotating about particular ____________.

Structural Isomers 1-butene 2-butene 2-methylpropene cyclobutane methylcyclopropane All have the molecular formula _______

Physical Properties of Structural Isomers Different structural arrangement can result in very different _________________________

Drawing Isomers Step 1 – Draw the longest continuous chain Step 2 – Remove one carbon from the chain and attach it as a methyl group in as many locations as possible Step 3 – Remove another carbon atom from the main chain and attach as another alkyl group

Try Some Draw isomers for C4H10 Practice Naming!! Butane and 2-methylpropane

Try some Example: C5H12

Cis-Trans Isomers Double Bonds do not rotate freely! Introducing a new type of isomer!

Cis-Trans Isomers Only occur with _______________________________________ This is because double and triple bonds do ______________freely In ________________________, rotation can occur freely and cis-trans isomers do not form

Formation of Cis-Trans Isomers Single bond can rotate YES Double bond cannot rotate

Cis-Trans Isomers Two isomers are possible when groups are attached to the double bond. In a cis isomer, groups are attached on the _______________________of the double bond. ________________________ In the trans isomer, the groups are attached on ______________________.

Naming Cis-Trans Isomers The prefixes cis or trans are placed in front of the alkene name when there are cis-trans isomers. cis-1,2-dibromoethene trans-1,2dibromoethene

Functional Groups Functional groups are ____________________________________________________found within molecules that are involved in the chemical reactions characteristic of those molecules. Hence the name, they are simply groups of atoms that can be attached to a hydrocarbon chain and have a specific _______________________________ This allows for different characteristics, reactions, etc. Functional groups can pertain to any molecules, but you will usually hear about them in the context of organic chemistry. The symbol _____ refers to a hydrogen or hydrocarbon side chain that is attached to a functional group

Functional Groups Type Structure Functional group R-F (Cl, Br, or I) R-OH R-O-R O R-C-H R-C-R װ װ

Functional Groups Type Structure Functional group O R-C-OH R-C-O-R R-NH2 R-C-NH2 װ װ װ