C
C
C
Functional Groups
World C — Carbon Chemistry
36.A — THE FOUNDATION
R
-FG
R36.01 The "Active Site"
- An atom or group of atoms attached to a hydrocarbon chain ($R$).
- Dictates the physical and chemical properties of the entire molecule.
- The hydrocarbon chain forms the skeleton; the functional group provides the behavior.
R36.10 Homologous Series
- A family of organic compounds with the *same* functional group.
- Successive members differ by a $-CH_2-$ unit.
- Same chemical properties, gradual change in physical properties (boiling point increases).
-COOH (Acid)
>C=O (Ketone)
-OH (Alcohol)
R36.11 Nomenclature Priority
- When multiple groups are present, IUPAC uses a priority list.
- Highest priority determines the suffix (e.g., *-oic acid*).
- Lower priority groups become prefixes (e.g., *hydroxy-*).
Alcohol (R-OH)
VS
Ether (R-O-R)
R36.12 Functional Isomerism
- Same molecular formula, entirely different functional groups.
- E.g., $C_2H_6O$ can be Ethanol (liquid, drinkable) or Dimethyl Ether (gas, anesthetic).
36.B — OXYGEN-CONTAINING GROUPS
R36.02 Alcohols (-OH)
- Contains the Hydroxyl group.
- Suffix: -ol (e.g., Methanol, Ethanol).
- Can form hydrogen bonds (high boiling points, soluble in water).
- Used as solvents, fuels, and beverages.
R36.03 Aldehydes (-CHO)
- Carbonyl group ($C=O$) located at the end of a chain.
- Suffix: -al (e.g., Methanal/Formaldehyde, Ethanal).
- Often have strong, pungent odors. Used in preservatives and resins.
R36.04 Ketones (>C=O)
- Carbonyl group ($C=O$) located in the middle of a chain.
- Suffix: -one (e.g., Propanone/Acetone).
- Excellent solvents for organic compounds (nail polish remover).
R36.05 Carboxylic Acids (-COOH)
- Contains Carbonyl and Hydroxyl on the same terminal carbon.
- Suffix: -oic acid (e.g., Ethanoic acid/Acetic acid/Vinegar).
- Weak acids; donate a proton ($H^+$) in water.
36.C — HALOGENS, AMINES & DERIVATIVES
R36.06 Haloalkanes (-X)
- One or more Hydrogens replaced by Halogens ($F, Cl, Br, I$).
- Prefix used: Fluoro-, Chloro-, Bromo-, Iodo-.
- Used as refrigerants, solvents, and anesthetics.
R36.07 Amines (-NH₂)
- Derivatives of Ammonia ($NH_3$).
- Suffix: -amine. Nitrogen has a lone pair of electrons.
- Act as weak organic bases. Crucial in amino acids and proteins.
R36.08 Esters (-COO-)
- Formed by reacting a Carboxylic Acid with an Alcohol.
- Suffix: -oate.
- Famous for distinct sweet, fruity smells (used in perfumes and flavorings).
R36.09 Ethers (-O-)
- An oxygen atom bonded to two alkyl groups.
- Names usually end in ether (e.g., Diethyl ether).
- Highly flammable, historically used as early anesthetics.