1. Organic Chemistry Nothing to do with organs

2. Bonding in organic chemistry Covalent bonds – sharing electrons Nonpolar covalent bonds – electronegativity difference of less than 0.5 units Polar covalent – EN difference of 0.5- 1.9 units EN difference of >1.9 is ionic (“  EN”) C–C  EN = 0, NPC

3. Bonding in organic chemistry C–H  EN = 0.35, NPC H–Cl  EN = 0.94, PC  + H Cl  – Lewis structures show all valence electrons – nonbonding as pairs of dots, and bonding as lines

4. Bonding in organic chemistry methanol All atoms must have full octet H, halogens make one bond

5. Bonding in organic chemistry (halogens have three lone pairs) O and S make two bonds (w/two lone pairs) N makes three bonds (one lone pair) C makes four bonds Double bonds – 4e-, represented by two lines

6. Bonding in organic chemistry formic acid acrylonitrile Triple bonds

7. Bonding in organic chemistry acetylene Shapes of molecules Bond angles – determined by valence- shell electron pair repulsion (VSEPR) between ligands (bonded group or lone pair)

8. Molecule Shapes Four groups – tetrahedral shape, 109.5º bond angles – ex. CH 4 methane

9. Molecule Shapes If one of the four groups is a lone pair, then the shape is trigonal pyramidal (ammonia)

10. Molecule Shapes H-N-H angles are 107.3º In water (bent geometry) H-O-H angles are 104.5º

11. Molecule Shapes Three groups – trigonal planar shape, 120º bond angles – BF 3

12. Molecule Shapes If ligands are not identical, then angles will deviate from 120º

13. Two groups – linear shape, 180º bond angles

14. Molecule Shapes Molecular polarity – a molecule is polar if it has polar bonds and asymmetry Polar examples: water, ammonia, methanol Nonpolar examples (with polar bonds): CO 2, CCl 4 Nonpolar examples (no polar bonds): methane, benzene

15. Functional groups Contain N, O, S, or halogens Are often the site of chemical reactivity of a molecule Used to divide organic compounds into classes Used as basis for naming organic compounds

16. Functional groups Alcohols -OH (hydroxyl) primary (1º) alcohol (methanol)

17. Functional groups secondary (2º) alcohol (2-propanol or isopropanol) CH 3 CHOHCH 3

18. Functional groups Tertiary (3º) alcohol (2-methyl-2- propanol or t-butyl alcohol) Draw all the alcohol isomers of C 4 H 10 O and label each as a primary, secondary or tertiary alcohol.

19. Functional groups Amines –NR 2 (amino – R can be H or a carbon containing group) Ammonia – NH 3 1º amine – CH 3 CH 2 NH 2 2º amine – CH 3 NHCH 3 3º amine – (CH 3 ) 3 N

20. Functional groups Aldehydes and ketones R 2 C=O (carbonyl) Ketone (acetone) Aldehyde (acetaldehyde)

21. Functional groups Carboxylic acids RCOOH (carboxyl group) Acetic acid