Tips for Organic Chemistry Success

1. Tips for Organic Chemistry Success • In order to successfully understand the various types of Organic molecules you should be able to identify each of the following for each type of molecule: • Structural characteristics (know the functional group) • Nomenclature (the rules for naming the molecules) • Physical and Chemical properties (basic/simple) • Occurrence and uses (common) • Preparation (what basic reactions produce the molecules) • Characteristic reactions of the molecules • For additional help, check out the Organic Chemistry section of the following website: • http://www.khanacademy.org/#browse

2. Organic vs. Inorganic Compounds • Inorganic compounds: cpds which are NOT hydrocarbons (~1.5 million) • Organic compounds: cpds which contain hydrogen & carbon (thus, hydrocarbons & derivatives) (~ 7 million) • “Organic Chemistry” started, as a branch of chemistry, when F. Wohler disproved the idea of “vital force.” - previously, it was thought that there were two types of matter (based on heating): melting/freezing cooking (required “vital force”)

3. Carbon Atoms • Carbon atoms generally form 4 bonds (think about their electron configuration) • In “organic” compounds these bonds are typically COVALENT. • Carbon readily forms bonds with other carbon atoms as well as with atoms of other elements. • Carbons w/ H’s attached are known as alkyl groups. • -CH3 methyl • -CH2CH3 ethyl

4. Hydrocarbons & their Derivatives • Hydrocarbons: H & C atoms only (the C & H atoms form the backbone of all organic molecules) • Derivatives: H, C & other elements • Saturated Hydrocarbons: all C-C bonds are “single.” • Alkanes and their derivatives • Unsaturated Hydrocarbons: one or more C-C bond(s) is/are multiple. • Alkenes, alkynes, aromatics & their derivatives

5. Basic Structural Features Chains of atoms Rings of atoms

6. Shapes of Organic Molecules The # of effective e- pairs around a center atom will determine the geometry of the molecule. # e- pairs e- pair geometry 2 pairs linear 3 pairs trigonal planar 4 pairs tetrahedral Remember, the e- pair geometry and the molecular geometry are NOT necessarily the same!

7. Drawing Organic Molecules Complete Structures: draw all atoms and all bonds, showing relative shapes Condensed Structures: write each alkyl (CHx) group separately. Skeletal Structures: carbon atoms at each line junction, assume enough H’s; draw all heteroatoms & their H’s.

8. The number of carbons in a chain is identified according to the following: # C name beginning 1 meth- 2 eth- 3 prop- 4 but- 5 pent- 6 hex- 7 hept- 8 oct- 9 non- 10 dec- The end of the name is based on C-C bonding: All single C-C bonds - end in “-ane” One or more double C-C bonds end in “-ene” One or more triple C-C bonds end in “-yne” Naming Organic Molecules

9. Functional Groups Functional groups contain a heteroatom, a multiple bond, or both and provide characteristic chemical & physical properties. Abbreviating the hydrocarbon backbone: R - fcn’l grp ex. R - Br alkyl halide R - OH alcohol (-OH is hydroxyl group) R - COOH carboxylic acid(-COOH is carboxyl group)

10. Single Alkyl halides Alcohols Ethers Amines Double (-C=O, carbonyl) Aldehydes Ketones Carboxylic Acids Amides Esters Single vs. Double bonds to Heteroatoms

11. Properties of Organic Cpds Polarity of molecule is determined by electronegativity differences and shape of molecule. Solubility: most are soluble in organic solvents water solubility is based on size of molecule & polarity.

12. Pollutants Organic pollutants affect the environment depending on their solubility. Ex. DDT (dichlorodiphenyltrichlorothane) Crude Oil

13. Water soluble: Lots of polar bonds & polar fcn’l groups Typically smaller molecules C and all the B’s Water insoluble: Lots of nonpolar bonds and few polar fcn’l groups Typically larger molecules A, D, E, K Vitamins