Alkanes and Alkenes

• Organic chemistry is the study of carbon-containing compounds.
• These compounds invariably contain carbon-hydrogen bonds.
• Functional groups are specific groups of atoms within molecules that are responsible for the characteristic chemical reactions of those molecules.
• Molecules can be classified based on their functional groups.
• A molecule can contain more than one functional group.

Hydrocarbons

• Hydrocarbons contain only carbon and hydrogen atoms.

Alkanes

• Alkanes are hydrocarbons containing only single bonds.
• They are also referred to as saturated hydrocarbons.
• Alkanes have the general formula CₙH₂ₙ₊₂.
• Alkanes are relatively unreactive.
• They undergo combustion, halogenation, and cracking reactions under specific conditions.

Alkenes

• Alkenes are hydrocarbons containing at least one carbon-carbon double bond.
• They are also referred to as unsaturated hydrocarbons.
• Alkenes have the general formula CₙH₂ₙ.
• Alkenes are more reactive than alkanes due to the presence of the π bond.
• They undergo addition reactions, polymerization, and oxidation reactions.

Alkynes

• Alkynes are hydrocarbons containing at least one carbon-carbon triple bond.
• They are also referred to as unsaturated hydrocarbons.
• Alkynes have the general formula CₙH₂ₙ₋₂.
• Alkynes are highly reactive due to the presence of two π bonds.
• They undergo addition reactions, polymerization, and oxidation reactions.
• Terminal alkynes (alkynes with a triple bond at the end of the carbon chain) are acidic.

Aromatic Hydrocarbons

• Aromatic hydrocarbons contain a benzene ring or a similar system of alternating single and double bonds.
• Benzene has the molecular formula C₆H₆.
• The π electrons in benzene are delocalized, making it particularly stable.
• Aromatic compounds undergo electrophilic aromatic substitution reactions.

Functional Groups Containing Halogens

• These functional groups contain a halogen atom (F, Cl, Br, I) bonded to a carbon atom.

Alkyl Halides (Haloalkanes)

• Alkyl halides have the general formula R-X, where R is an alkyl group and X is a halogen.
• They are named by adding the prefix fluoro-, chloro-, bromo-, or iodo- to the name of the parent alkane.
• Alkyl halides can undergo nucleophilic substitution reactions (SN1 and SN2) and elimination reactions (E1 and E2).
• The reactivity of alkyl halides depends on the nature of the halogen and the structure of the alkyl group.

Aryl Halides

• Aryl halides have a halogen atom directly bonded to an aromatic ring.
• Aryl halides are generally less reactive than alkyl halides towards nucleophilic substitution reactions.
• They can undergo nucleophilic aromatic substitution under specific conditions.

Functional Groups Containing Oxygen

• These functional groups contain oxygen atoms bonded to carbon atoms or other heteroatoms.

Alcohols

• Alcohols have the general formula R-OH, where R is an alkyl group.
• They contain a hydroxyl (-OH) group bonded to a saturated carbon atom.
• Alcohols are named by replacing the -e ending of the parent alkane with -ol.
• They are polar and can form hydrogen bonds.
• Alcohols undergo dehydration to form alkenes, oxidation to form aldehydes or ketones or carboxylic acids, and esterification with carboxylic acids.
• Primary (1°) alcohols are bonded to one other carbon atom, secondary (2°) alcohols are bonded to two, and tertiary (3°) alcohols are bonded to three.

Ethers

• Ethers have the general formula R-O-R', where R and R' are alkyl or aryl groups.
• They contain an oxygen atom bonded to two carbon atoms.
• Ethers are named by listing the alkyl groups attached to the oxygen atom alphabetically, followed by the word "ether."
• Ethers are relatively unreactive but can undergo cleavage under strongly acidic conditions.
• They are commonly used as solvents.

Aldehydes

• Aldehydes contain a carbonyl group (C=O) with one hydrogen atom and one alkyl or aryl group attached to the carbon.
• They have the general formula R-CHO. The carbonyl group is at the end of the carbon chain.
• Aldehydes are named by replacing the -e ending of the parent alkane with -al.
• They are more reactive than ketones due to the presence of the hydrogen atom on the carbonyl carbon.
• Aldehydes undergo oxidation to form carboxylic acids, reduction to form primary alcohols, and addition reactions with nucleophiles.

Ketones

• Ketones contain a carbonyl group (C=O) with two alkyl or aryl groups attached to the carbon.
• They have the general formula R-CO-R'. The carbonyl group is within the carbon chain.
• Ketones are named by replacing the -e ending of the parent alkane with -one.
• They are less reactive than aldehydes due to the steric hindrance of the two alkyl groups on the carbonyl carbon.
• Ketones undergo reduction to form secondary alcohols and addition reactions with nucleophiles.

Carboxylic Acids

• Carboxylic acids contain a carboxyl group (-COOH), which consists of a carbonyl group and a hydroxyl group attached to the same carbon atom.
• They have the general formula R-COOH.
• Carboxylic acids are named by replacing the -e ending of the parent alkane with -oic acid.
• They are acidic and can donate a proton.
• Carboxylic acids undergo esterification with alcohols, amide formation with amines, and reduction to form primary alcohols.

Esters

• Esters have the general formula R-COOR', where R and R' are alkyl or aryl groups.
• They are derived from the reaction of a carboxylic acid and an alcohol.
• Esters are named by first naming the alkyl group from the alcohol, followed by the name of the carboxylic acid with the -ic acid ending replaced by -ate.
• Esters undergo hydrolysis to form carboxylic acids and alcohols, and transesterification with other alcohols.

Functional Groups Containing Nitrogen

• These functional groups contain nitrogen atoms bonded to carbon atoms or other heteroatoms.

Amines

• Amines are derivatives of ammonia (NH₃) in which one or more hydrogen atoms are replaced by alkyl or aryl groups.
• Primary (1°) amines have the general formula R-NH₂, secondary (2°) amines have the general formula R-NH-R', and tertiary (3°) amines have the general formula R-N(R')R''.
• Amines are named by adding the prefix amino- to the name of the parent alkane or by listing the alkyl groups attached to the nitrogen atom followed by the word "amine."
• Amines are basic and can accept a proton.
• They undergo reactions with acids to form salts, acylation with acyl chlorides or anhydrides to form amides, and alkylation with alkyl halides to form quaternary ammonium salts.

Amides

• Amides have the general formula R-CO-NR'R'', where R, R', and R'' are alkyl or aryl groups or hydrogen atoms.
• They contain a carbonyl group bonded to a nitrogen atom.
• Amides are named by replacing the -oic acid ending of the parent carboxylic acid with -amide.
• Amides are relatively stable and less reactive than esters.
• They undergo hydrolysis to form carboxylic acids and amines.

Nitriles

• Nitriles have the general formula R-CN, where R is an alkyl or aryl group.
• They contain a carbon-nitrogen triple bond.
• Nitriles are named by adding the suffix -nitrile to the name of the parent alkane.
• Nitriles can be hydrolyzed to form carboxylic acids, reduced to form primary amines, and react with Grignard reagents to form ketones.

Functional Groups Containing Sulfur

• These functional groups contain sulfur atoms bonded to carbon atoms or other heteroatoms.

Thiols

• Thiols, also known as mercaptans, have the general formula R-SH, where R is an alkyl or aryl group.
• Thiols are named by adding the suffix -thiol to the name of the parent alkane or by using the prefix mercapto-.
• Thiols are similar to alcohols but have a sulfur atom instead of an oxygen atom.
• Thiols are more acidic than alcohols and have a strong, unpleasant odor.
• Thiols undergo oxidation to form disulfides.

Sulfides

• Sulfides, also known as thioethers, have the general formula R-S-R', where R and R' are alkyl or aryl groups.
• Sulfides are named by listing the alkyl groups attached to the sulfur atom followed by the word "sulfide."
• Sulfides are similar to ethers but have a sulfur atom instead of an oxygen atom.
• Sulfides can be oxidized to form sulfoxides and sulfones.