Lecture on Organic Chemistry

Definition and Scope

• Organic Chemistry: Deals with carbon compounds.
• Excludes some carbon compounds like carbon dioxide.

Historical Context

• 19th Century Beliefs: Strict division between organic and inorganic chemistry; only living things could make organic chemicals.
• Friedrich Wöhler (1828): Synthesized urea in a lab from inorganic chemicals, challenging previous beliefs.

Evolution of the Chemical Industry

• 19th Century: Chemical industry developed, especially the dyestuff industry.
  • Dyes were originally sourced from plants and animals.
  • Chemists discovered dyes could be synthesized in laboratories.
  • Example: Perkin's attempt to synthesize quinine accidentally led to synthetic dye discovery.

Health and Pharmaceuticals

• Quinine: Attempt to synthesize for malaria treatment led indirectly to the dyestuff industry.
• Antibiotics and Pharmaceuticals: Major contributions from organic chemistry.
  • Many PhD students in organic chemistry contribute to pharmaceutical innovations.

Important Organic Chemicals

• Alcohol: Studied using NMR spectroscopy and MRI techniques.
  • Example: Ethyl alcohol (ethanol)
• Alkanes: Fundamentals of organic chemistry (methane, ethane, propane, etc.)
• Sugars: Significant in biological systems, cell surfaces, and genetic identity (blood groups and DNA).
• Biomolecules: Includes DNA, RNA, proteins, and more.
• Petroleum Products: Plastics, nylon, and other materials derived from petroleum.

Key Concepts in Organic Chemistry

1. Stereochemistry

• Study of the three-dimensional structure of molecules.
• Importance of molecular models in understanding shapes and spatial arrangements.

2. Functional Groups

• Collections of atoms with specific properties (e.g., hydroxyl group in alcohols).
• Allow prediction of chemical and physical properties.
• Examples: Carboxylic acids, ketones, aldehydes, carbonyl groups, etc.

3. Curved Arrow Notation

• Depicts the flow of electrons in chemical reactions.
• Key to understanding reactivity and bond formation/breaking.
• Helps predict how different molecules react.

Summary

• Organic chemistry is crucial in understanding a wide range of chemicals, from synthetic compounds to biomolecules.
• Mastery of stereochemistry, functional groups, and curved arrow notation are essential for predicting molecule behavior and reactions.