Organic Chemistry Overview

Introduction

• Focus on organic compounds containing carbon atoms.
• Carbon likes to form four bonds.

Bond Preferences of Elements

• Group 1 (e.g., Hydrogen): 1 bond
• Beryllium: 2 bonds
• Boron: 3 bonds
• Carbon: 4 bonds
• Nitrogen: 3 bonds
• Oxygen: 2 bonds
• Halogens (e.g., Fluorine, Chlorine, Bromine, Iodine): 1 bond

Drawing Lewis Structures

• Water (H2O): Oxygen forms 2 bonds, Hydrogen forms 1 bond
• Methyl Fluoride (CH3F): Carbon in middle, 3 Hydrogens, 1 Fluorine with lone pairs

Bond Types and Polarity

• Polar Bonds: Electronegativity difference ≥ 0.5 (e.g., C-F bond)
• Non-polar Bonds: Electronegativity difference < 0.5 (e.g., C-H bond)
• Hydrogen Bonds: H attached to N, O, F

Covalent vs. Ionic Bonds

• Covalent Bonds: Electrons shared (polar and non-polar)
• Ionic Bonds: Electrons transferred (e.g., NaCl)

Types of Organic Compounds

• Alkanes: Saturated (CnH2n+2), named (Methane, Ethane, Propane, etc.)
• Alkenes: Contain double bonds (e.g., Ethene)
• Alkynes: Contain triple bonds (e.g., Ethyne)

Properties of Bonds

• Bond Length: Single > Double > Triple
• Bond Strength: Triple > Double > Single
• Sigma vs. Pi Bonds: Sigma stronger than Pi

Hybridization

• sp3: 4 groups
• sp2: 3 groups
• sp: 2 groups

Formal Charge Calculation

• Formula: Valence electrons - (Bonds + Dots)
• Examples: Sulfur (6-7=-1), Nitrogen (5-4=1)

Functional Groups

• Alcohol (OH group): Example Ethanol
• Aldehyde (CHO group): Example Ethanal
• Ether (C-O-C): Example Dimethyl Ether
• Ketone (RCOR'): Example Propanone
• Carboxylic Acid (COOH): Example Pentanoic Acid
• Ester (COOR): Example Methyl Ethanoate

Expanded Structures

• Methane (CH4), Methanol (CH3OH), Ethene (C2H4), Ethyne (C2H2), etc.

Bond and Electron Counting

• Sigma and Pi Bonds: Counting in organic molecules
• Non-bonding Electrons: Lone pairs

Additional Topics

• Additional exercises on various structures and their expanded forms.