Organic Chemistry Functional Groups

Functional Groups Carbon can form strong covalent bonds with oxygen, nitrogen, fluorine, chlorine, bromine, iodine, sulfur and phosphorous Functional group – an atom or group of atoms substituted on an organic molecule that always react in a certain way By adding a functional group, the physical and chemical properties of the parent chain are altered

Halocarbons Contain a halogen substituent -X R-X = Halocarbon Alkyl halide - halogen covalently bonded to an aliphatic carbon (carbon that is not part of a benzene ring) Aryl halide – halogen bonded to an aromatic group

difluoroethane

Alcohols -OH hydroxyl group R-OH = Alcohol Oxygen will have 2 lone pairs; hydroxyl group is moderately polar and can form hydrogen bonds Use a number to indicate position of functional group and change ending to –ol Use a prefix before –ol for more than one hydroxyl group

Alcohols methanol CH3OH ethanol CH3CH2OH 1-propanol CH3CH2CH2OH 2-propanol CH3CH(OH)CH3 common name: isopropyl alcohol

Ethers Ethers are compounds with two alkyl groups bonded to the same oxygen General formula: R-O-R or R-O-R’ Oxygen cannot form hydrogen bonds Volatile & lower boiling points than alcohols Less soluble in H2O than alcohols

Ethers Naming: For symmetrical ethers = name alkyl group and add “ether” For asymmetrical ethers = name 2 alkyl groups and list alphabetically CH3CH2-O-CH2CH3 ethyl ether CH3CH2-O-CH2CH2CH3 ethylpropyl ether

Aldehydes and Ketones

Aldehydes Carbonyl group located at END of carbon chain Polar, reactive, & lower boiling points than similar alcohols Naming: drop “e” at end of parent chain and add “-al” No numbers are needed unless there is a branched chain or another functional group

ethanal (also called acetaldehyde)

Ketones Carbonyl group located within the carbon chain (not at end of chain) Polar & less reactive than aldehydes Naming: drop “e” at end of parent chain and add “-one” Indicate carbonyl position number in front of the name

2-propanone (also called acetone)

Carboxylic Acids

Carboxylic Acids Carboxyl group also written -COOH Naming: Drop –ane of parent chain and add “-anoic acid” Polar, reactive & will ionize in aqueous solution

Ethanoic acid also called acetic acid CH3COOH

Esters In an ester, the hydrogen of the carboxyl group is replaced by an alkyl group Ester group -COO Ester RCOOR’ Polar, sweet smelling (fruits and flowers) Naming: drop the “-ic acid” from the acid and add “–ate”. Name the alkyl group that replaced the hydrogen and place in front of name

Methyl ethanoate

Amines Amines are derivatives of ammonia When one or more hydrogens of ammonia is replaced by an alkyl group, an amine is the result. Like ammonia, amines tend to be basic and have similar odors.

Amines

Amines Naming add “amine” to end of parent chain designate amino group by number when necessary Use prefix in front of “amine” to indicate number of amino groups

Ethylamine

Amides

Amides Nitrogen bonded to carbonyl carbon Amides are found in natural proteins and some synthetica materials Naming : drop final “–ane” from alkane and replace with “–yl” and add “amide”

Ethylamide

Acetaminophen