BMS1011 Wk2L1 flashcards

Overview of Organic Chemistry

• Transition from molecular bonding and pH to organic chemistry.

• Focus on functional groups rather than detailed mechanisms and reactions.

• Aim: Predict molecular properties based on functional groups.

Learning Outcomes for Week 2

• Understand the family of functional groups in chemistry.

• Familiarize with line drawings (molecule representation).

• Introduction to IUPAC nomenclature (International Union of Pure and Applied Chemistry).

• Discuss physical properties of molecules.

Drawing Structures

• Lewis Structures: Detailed representation showing every atom and covalent bonds.

  • Sticks/Lines represent covalent bonds (2 electrons).

  • Mimics bond angles (e.g., sp3 hybridization - 109 degrees).

• Condensed Formulas: Simplifies molecules by grouping atoms.

  • Example: CH3-CH2-CH2-CH3 for butane.

  • Emphasis on efficiency over detailed representation.

• Line Structures: Most efficient for larger molecules.

  • Shows only skeleton of molecule; each line is a bond between atoms.

  • End of line represents carbon; protons are not explicitly denoted.

  • Assumes presence of necessary hydrogen atoms for carbon's four bonds.

Carbon Classifications

• Primary Carbon: Connected to one other carbon (3 protons).

• Secondary Carbon: Connected to two other carbons (2 protons).

• Tertiary Carbon: Connected to three other carbons (1 proton).

• Quaternary Carbon: Connected to four other carbons (no protons).

• Classification affects reactivity.

Functional Groups

• Definition: An atom or group of atoms within a molecule determining characteristic properties.

• Common functional groups in organic compounds:

  • Alkanes: Saturated hydrocarbons (C-C single bonds).

  • Alkenes: At least one C=C double bond.

  • Alkynes: At least one C≡C triple bond.

  • Arenes: Aromatic compounds with cyclic structures (e.g., benzene).

  • Alcohols: Contain hydroxyl group (–OH).

  • Ethers: Oxygen between two carbon groups.

  • Aldehydes and Ketones: Contains carbonyl group (C=O).

  • Carboxylic Acids: Contains carboxyl group (–COOH).

  • Amines: Contain nitrogen (–NH2).

Examples of Functional Groups

• Alcohol: –OH group, e.g., ethanol.

• Ethers: R-O-R' structure.

• Aldehydes: R-CHO structure.

• Ketones: R-CO-R' structure.

• Carboxylic Acid: R-COOH; characteristic of organic acids.

• Esters: Derived from carboxylic acids; RCOOR' structure.

• Amides: -C(O)NR2 structure; derivatives of carboxylic acids.

• Haloalkanes: Halogen substituents on alkanes (e.g., -Br, -Cl).

• Thiols: Contain a sulfhydryl group (R-SH).

Importance of Functional Groups

• Essential for understanding reactivity and physical properties of organic molecules.

• Must become second nature to recognize and classify functional groups.

• Encouraged to practice identification and drawing of molecules along with functional groups.

Summary

• Organic chemistry focuses on the structure, properties, and reactions of carbon-containing compounds.

• Mastery of functional groups and nomenclature is crucial for identifying and predicting molecular behavior.