Lec 1 - Introduction to Organic Chemistry PDF

Organic Chemistry Analytical Chemistry Assoc. Prof. Dr. Rania Helmy Arisha What is organic chemistry? The study of organic compounds: ✓Structure ✓Properties ✓Preparation ✓Reactions Organic compounds (Natural or Synthetic)  Organic compounds Mainly contain C w...

Organic Chemistry Analytical Chemistry Assoc. Prof. Dr. Rania Helmy Arisha What is organic chemistry? The study of organic compounds: ✓Structure ✓Properties ✓Preparation ✓Reactions Organic compounds (Natural or Synthetic)  Organic compounds Mainly contain C with other elements H, O, N, S, Cl, Br, ………etc What are the 4 main elements in organic compounds? Four elements, carbon, hydrogen, oxygen and nitrogen, are the major components of most organic compounds. Consequently, our understanding of organic chemistry must have, as a foundation, an appreciation of the electronic structure and properties of these elements. From our previous study in chemistry; we knew that the atom consists of central positively charged nucleus surrounded by negatively charged electrons in energy levels Carbon Tetravalent atom Hydrogen C Tetravalent atom H Monovalent atom Nitrogen Trivalent atom Oxygen Divalent atom  single lone pair is found in nitrogen atom, such as nitrogen in ammonia. Two lone pairs are found in oxygen atom, such as oxygen in water Free electrons Non-bonding electrons  Chemical Bonds Structural Non-Structural (Constitutional) (Non-Constitutional) Structural (Constitutional) Chemical Bonds 1- Ionic Bond: NaCl 1- Ionic Bond: Electron transfer Cation - Anion attraction 2- Covalent Bond: Common bond in organic molecules Electron sharing 2 Methods for classification of Covalent Bonds Covalent Bond may be Single Double Triple Electronegativity C-C H-H C-O C-N C - Cl C - Br  Second Method for classification of Covalent Bonds A- Non polar covalent bond When the 2 atoms are the same C–C H-H Or not the same but with very small electronegativity difference C-H  B- polar covalent bond When the 2 atoms are different with large electronegativity difference Water (H2O) molecule Charges are partial not complete charges  Question: Classify the following bonds Double bond Polar Covalent bond Triple bond Non-Polar Covalent bond Thank You