1. Alcohols can be thought of as organic relatives of water:
H-O-H water R-O-H alcohol
Recall: R stands for a radical, the rest of the molecule. ••

2. Classification as primary, secondary & tertiary: what kind of carbon is the OH bonded to?
CH3CH2CH2CH2OH is a primary (or 1°) alcohol
CH3CHCH2CH3 is a secondary (or 2°) alcohol OH

3. CH3C-OH is a tertiary
(or 3°) alcohol
CH3

4. Molecular Geometry & Bonding four e– pairs on O bond angle ~109°
e- pairs tetrahedral O
R H molecular shape:
angular or bent

5. Nomenclature of Alcohols
1. Find longest carbon chain containing the C-OH.
2. Parent name is alkane + ol = “alkanol” .
3. Number chain so C of C-OH gets lowest possible number.

6. Example
CH3CH2CHCH2CHCH2CHCH3 OH
CH2CH3
CH3
5-ethyl-7-methyl-3-octanol

7. Example 2
CHCH3
CH3 H HO
trans-3-isopropylcyclopentanol 2 1 3

8. The O-H bond of alcohols is polar covalent, just as in water.
The permanent dipoles are: O
C H d+ d- d+
O-H more polar than O-C
other bonds
to C

9. Alcohols form “hydrogen bonds” like water does.
A H-bond is an intermolecular attraction between the H of an O-H or N-H bond in one molecule and the unshared electron pairs on :O: or N: in another molecule.

10. The molecule with the O-H or N-H in the H-bond is the H-bond donor.
A molecule that has a N: or :O: particpating in a H-bond is an electron pair donor. It is called a H-bond acceptor.

11. ROH is both donor & acceptor for H-bonds•
H-O
= H-bond
O-R
ROH is both donor & acceptor for H-bonds

12. H-bonds make a molecule seem heavier -- cause an increase in boiling point compared to other compounds of same molecular weight.
CH3CH2-O-CH2CH3 bp 35° C
CH3CH2CH2CH2OH bp 118° C