Introduction to Organic Chemistry and IUPAC Nomenclature

organic chemistry- chemistry concerning carbon-containing compounds

Why is Carbon Special?

• can form strong bonds with multiple atoms of itself in a chain
• can bond with many other elements like hydrogen, nitrogen, sulfur, oxygen, and phosphorus
  • brings diversity in compounds that can be formed
  • this allows it to be the basis of life
• carbon can also form double and triple bonds
• carbon is tetravalent- it can remove/gain 4 electrons
• functional groups- increase the functionality/reactivity of a molecule

Other Elements

• oxygen is divalent- it can gain 2 electrons
• nitrogen is trivalent- it can gain 3 electrons
• hydrogen is always monovalent- it can lose 1 electron

Types of Structures/Formulas & Other Conventions

• lewis structures- show lone pairs as well as number & type of bond present in the molecule

• condensed formula- writing the carbons with their hydrogens

  • example- C20H42O can also be written as CH3(CH2)19OH

• **bond line formula- **shown below

  

• n-(insert molecular formula or name of hydrocarbon) means it’s “normal” & not branched

  • example- *n-*butane

• isomers- molecules with the same molecular formula but different structures

  • the number of isomers tends to increase as the number of carbons in the compound increases

Hydrocarbons

• made of only carbon and hydrogen
• not very functionally useful
• mostly used for energy
• 2 types
  • saturated- maximum amount of hydrogens are in the molecule, all carbons have single bonds
  • also called alkanes
  • unsaturated- some carbons have double or triple bonds

IUPAC Nomenclature

• parent chain is the longest identifiable carbon chain present in the molecule
  • if 2 chains have the same length, the parent chain is the one with the most substituents
• carbons in the chain are numbered so the substituents get the lowest number possible
  • if some substituents have the same number no matter numbering from left to right, numbering starts from the end where the next substituent has the lowest number
• give the lowest number to the substituent whose letter is first in the alphabet
• if more than one of the same type of substituent is present, use the prefixes di- for 2, tri- for 3, tetra- for 4, etc. to indicate the number
• substituents are listed in alphabetical order
  • ignore numerical prefixes in alphabetization (like di-, tri-, tetra-)
  • don’t ignore positional prefixes like iso-
• names and numbers are separated by dashes

multiple numbers are separated by commas

• halogens as substituents
  • F: fluoro-
  • Cl: chloro-
  • Br: bromo-
  • I: iodo-

Example

\