Unit 3: Alcohols and Alkyl Halides

functional groups

reactive portions that differ from alkanes

molecules are described by their

alkane group plus modifications

Alcohols (ROH)

r= alkane portion

OH = alcohol

Alkyl halides (RX)

X= represents halogens

R= alkane portion

Alkenes

isolated double bonds

Alkynes

isolated triple bonds

Arenes

benzene rings

Amines

will use as reactants, important to know nomenclature

Epoxides

three-membered ring with unique reactivity

Ethers (ROR’)

made from alcohols and alkyl halides reactions

Thiols/Sulfies

like alcholhols but with sulfur

What are the carbonyl-containing groups?

Aldehydes, ketones, carboxylic acids

Aldehydes

C-=O with H on one side

Ketones

C=O with two R groups

Carboxylic acids

C=O WITH OH ACTUALLY ACIDIC

Describe oxygen hybridization

1. Oxygen is sp³ hybridized with two line pairs in terahedral genometry

2. Lone pairs sit in sp³ orbitals like wedge and dash

Dipole movements are measured in

Debye

Water

1.8 D

Methanol

1.7 D

Chloromethane

1.9 D

Name the key intermolecular forces of concern

dipole-dipole interactions, hydrogen bonding, polarizability

dipole-dipole interactions : polar molcules hav prefered interactions; describe them

positive poles attract negative poles,

stronger than London dispersion forces in alkanes

Special dipole interaction unique to Oh and NH groups is ________. Described as highly directional interactions between H and Lps.

Hydrogen bonding

What explains the high boiling point of ethanol

hydogen bonding interactions

Are alkanes considered functional groups?

no, although C-H bonds can be reactive

What are the two types of nomenclature for alkyl halides

functional class nomenclature and substitutive nomenclature

functional class nomenclature

the alkyl group is treated as the “positive” portion of a halide salt

substitutive nomenclature

the halogen is treated as a “helo-” substituent on an alkyl chain

How many alkyl groups are attached directly to the carbon that bears the functional group?

revealed by substitution pattern

one alkyl group

primary (1 degree)

two alkyl groups

secondary (2 degree)

three alkyl groups

tertiary (3 groups)

substitution pattern can profoundly affect the reactivity of a

carbon

dipole movements are comparable to that of

water

Electrostatic potential plots (eplots)

measure polarity by showing us where relative electron densities differ

Alchohols and alkyl halides are

polar

hydrogen bonds are

directional, and involved a small degree of electron sharing

The ability of the electron around an atom to distort its shape is called

polarizability

Polarizability is greater for

larger halogens

greater polarizability means a

larger boiling point

Boiling point increases with

molecular weight

Boiling points of alcohols are quite high

due to hydrogen bonding

Alkyl halides are

insoluble in water

Alc can ______ bond with water

hydrogen