Organic Chemistry Overview

Organic Chemistry

• Definition: Study of carbon-containing compounds and their properties.
• Key Elements: Primarily involves carbon, hydrogen, oxygen, nitrogen, sulfur, and phosphorus.
• Functional Groups:
  • Hydroxyl (-OH): Alcohols
  • Carbonyl (C=O): Ketones and Aldehydes
  • Carboxyl (-COOH): Carboxylic acids
  • Amino (-NH₂): Amines
  • Ester (-COOR): Esters
• Classifications:
  • Aliphatic: Straight or branched chain hydrocarbons (alkanes, alkenes, alkynes)
  • Aromatic: Compounds containing benzene rings
• Isomerism:
  • Structural isomers: Different connectivity of atoms
  • Stereoisomers: Same connectivity but different spatial arrangements
    • Geometric (cis-trans)
    • Optical isomers (enantiomers)
• Reactions:
  • Addition, substitution, elimination, and rearrangement reactions.
  • Mechanisms: Nucleophilic, electrophilic, and radical mechanisms.

Chemical Bonding

• Definition: The forces that hold atoms together in compounds.
• Types of Bonds:
  • Ionic Bonds:
    • Formed by the transfer of electrons from one atom to another.
    • Typically between metals and non-metals.
    • Results in charged ions (cations and anions).
  • Covalent Bonds:
    • Formed by the sharing of electrons between atoms.
    • Typically between non-metals.
    • Can be polar (unequal sharing) or nonpolar (equal sharing).
  • Metallic Bonds:
    • Involve a 'sea of electrons' shared among a lattice of metal atoms.
    • Responsible for properties like conductivity and malleability.
• Bond Strength: Generally, covalent bonds are stronger than ionic bonds; bond strength is affected by bond order.
• Bond Angles and Shapes:
  • VSEPR Theory: Used to predict the geometry of molecules based on electron pair repulsion.
  • Common shapes include linear, trigonal planar, tetrahedral, trigonal bipyramidal, and octahedral.
• Hybridization: The mixing of atomic orbitals to form new hybrid orbitals (e.g., sp³ for tetrahedral).

These notes cover the essential concepts and classifications within Organic Chemistry and Chemical Bonding.

Organic Chemistry

• Definition: Study focused on carbon-containing compounds and their properties.
• Key Elements: Primarily consists of carbon (C), hydrogen (H), oxygen (O), nitrogen (N), sulfur (S), and phosphorus (P).
• Functional Groups: Specific groups of atoms within molecules that determine their chemical reactivity.
  • Hydroxyl (-OH): Found in alcohols, responsible for their solubility and reactivity.
  • Carbonyl (C=O): Present in ketones and aldehydes, important for reactions like oxidation and reduction.
  • Carboxyl (-COOH): Characterizes carboxylic acids, responsible for acidity and formation of esters.
  • Amino (-NH₂): Found in amines, determines basicity and involved in protein formation.
  • Ester (-COOR): Present in esters, important for flavors and fragrances.
• Classifications: Categorized based on the arrangement and structure of carbon atoms.
  • Aliphatic: Straight or branched chain hydrocarbons, further divided into alkanes, alkenes, and alkynes.
  • Aromatic: Compounds containing benzene rings, characterized by their stability and unique chemical properties.
• Isomerism: Molecules with the same molecular formula but different arrangements of atoms.
  • Structural isomers: Differ in the connectivity of their atoms, resulting in different structural formulas.
  • Stereoisomers: Possess identical connectivity but differ in their spatial arrangements.
    • Geometric isomers (cis-trans): Differ in the arrangement of groups around a double bond.
    • Optical isomers (enantiomers): Non-superimposable mirror images of each other.
• Reactions: Chemical processes involving the breaking and forming of bonds in organic molecules.
• Common types: Addition, substitution, elimination, and rearrangement reactions.
• Mechanisms: Step-by-step processes that explain how organic reactions occur.
• Nucleophilic: Involve an electron-rich species (nucleophile) attacking an electron-deficient species.
• Electrophilic: Involve an electron-deficient species (electrophile) attacking an electron-rich species.
• Radical: Involve species with unpaired electrons.

Chemical Bonding

• Definition: The forces that hold atoms together in compounds, creating molecules and solids.
• Types of Bonds: Different types of bonds involving the sharing or transfer of electrons.
  • Ionic bonds:
    • Formed by the transfer of electrons from one atom to another, typically involving metals and nonmetals.
    • Result in charged ions (cations and anions) held together by electrostatic attraction.
  • Covalent bonds:
    • Formed by the sharing of electrons between atoms, mainly between nonmetals.
    • Can be polar (unequal sharing) or nonpolar (equal sharing) based on the electronegativity difference between atoms.
  • Metallic bonds:
    • Involve a "sea of electrons" delocalized across a lattice of metal atoms.
    • Responsible for metallic properties like conductivity, malleability, and ductility.
• Bond Strength: The strength of the attractive force holding atoms together.
  • Generally: Covalent bonds are stronger than ionic bonds.
  • Factors affecting bond strength: Bond length, bond order, and electronegativity difference.
• Bond Angles and Shapes: The spatial arrangement of atoms within a molecule.
  • VSEPR theory (Valence Shell Electron Pair Repulsion): Predicts the geometric shape of molecules based on the repulsion between electron pairs around a central atom.
    • Common shapes: Linear, trigonal planar, tetrahedral, trigonal bipyramidal, and octahedral.
• Hybridization: Process where atomic orbitals mix to form new hybrid orbitals with modified shapes and energies.
  • Example: sp³ hybridization, involved in tetrahedral structures like methane (CH₄).