Chem 31

• Organic chemistry is the study of compounds containing CARBON.
• Why is CARBON special?

  • Of the more than 37 million presently known chemical compounds, more than 99% of them contain carbon.
  • Carbon can share FOUR valence electrons and form four strong covalent bonds (which can either be single, double, or triple bond), forming a stable tetrahedral geometry.
  • Carbon stands out for its ability to create a wide range of compounds. It bonds readily with itself, forming chains (polymerism), and can also produce compounds with the same number of atoms but different structures (isomerism).
• There are three generally accepted sources of organic compounds:

  – carbonized organic matter (e.g., fossil fuels)

  – living organisms (e.g., essential oil from plants)

  – invention/human ingenuity (e.g., drug discovery)
• When to say it’s Organic?

  • Organic chemistry is the study of compounds containing carbon, both naturally occurring and synthetic compounds.
  • Other elements may also be present. Any atom that is not carbon or hydrogen is called a heteroatom (e.g., N, O, S, P, and the halogens).
• NOT all compounds with carbons are organic.

  Consider the following compounds:

  • ✓ carbonate (CO3 2- )
  • ✓ cyanide (CN- )
  • ✓ bicarbonate (HCO3 - )
  • ✓ carbon dioxide (CO2 )
  • ✓ carbon monoxide (CO)
• Remember that organic compounds are compounds that were either once-living or derived from something that was once living, or they can be synthesized.
• Organic vs. Inorganic

  ORGANIC INORGANIC

  Nature Based on C Not based on C (Sometimes

  contain carbon but not C-H bonds)

  Bonding Usually covalent Often ionic

  IMF Generally weak Quite strong

  Physical Low BP & MP High BP & MP

  property

  Flammability Often flammable Usually non-flammable Example Derived from living Minerals and ores

  or once-living matter
• Theory of Vitalism. In 1800’s, organic compounds are believed to have originated from living organisms, and only living things could synthesize organic compounds through intervention of a vital force.
• However, in 1828, Friedrich Wöhler discovered that urea, an organic compound, could be made by heating the inorganic compound ammonium cyanate.