2.1 UNSATURATED HYDROCARBONS A hydrocarbon in which one or more carbon-carbon multiple bonds are present. Carbon-carbon multiple bonds are chemically very reactive Parts of organic compounds that are very reactive are called FUNCTIONAL GROUPS

FUNCTIONAL GROUPS C H C H O If one or more hydrogens are replaced by a new bond C H or a different atom a Functional Group is created. C H O

FUNCTIONAL GROUPS DEFINE A CLASS OF COMPOUND Compounds in a class have similar physical properties and chemical reactions. ARE A REACTIVE SITE Define the chemistry (reactions) for the group.

FUNCTIONAL GROUPS PROVIDE A BASE FOR NAMING COMPOUNDS For instance, all ketones have the ending -ONE in their names. acetone methyl ethyl ketone cyclopropanone CONSIST OF UP TO 5 ATOMS Specific structure Specific shape

KNOW YOUR FUNCTIONAL GROUPS YOU SHOULD MEMORIZE THE NEXT TWO SLIDES (see the handout ). Know how to draw the Lewis Diagrams for these functional groups YOU SHOULD ALSO MEMORIZE THE TABLE OF COMMON ABBREVIATIONS THAT IS PRESENTED IN THE SECTION THAT FOLLOWS

COMMON FUNCTIONAL GROUPS CLASS FUNCTIONAL GROUP R R ALKENES double bond R C C R R can be H C C AROMATICS Any compound which has a benzene ring is “aromatic” or “benzenoid” benzene ring ALCOHOLS R O H hydroxyl ETHER alkoxy R cannot be H H cannot be R ( R = any group of carbon and hydrogen atoms ) ( Take special care where red arrows indicate )

FUNCTIONAL GROUPS ….. continued CLASS FUNCTIONAL GROUP carboxyl R C O C O CARBOXYLIC ACIDS R can be H O H O H ester R C O C O R can be H ESTERS R’ cannot be H O R’ O R R C H O aldehyde carbonyl ALDEHYDES KETONES R cannot be H H cannot be R AMINES amino H can be R AMIDES amide H can be R R can be H

SPECIAL ABBREVIATIONS (condensed formulas) GROUPS WITH SPECIAL ABBREVIATIONS (condensed formulas)

SPECIAL ABBREVIATIONS ( continued ) -C6H5 benzene ring .. : -CHO aldehyde ( note H before O, -C-OH is an alcohol) .. (CO) or CO carbonyl group :

SPECIAL ABBREVIATIONS KNOW THESE - including electron pairs .. : -COOH carboxylic acid -CO2H .. : ester -COOR .. -CO2R .. .. -NH2 amino group .. : -CONH2 amide ..

MULTIPLE FUNCTIONAL GROUPS MOLECULES WITH MULTIPLE FUNCTIONAL GROUPS

IDENTIFYING FUNCTIONAL GROUPS amine alcohol alkene amide ethers Circle and name the functional groups.