Hydrocarbon Derivatives:

Halocarbons, Alcohols, & Ethers

Hydrocarbons

• Contain only carbon & hydrogen

• carbon can also form strong covalent bonds with other elements such as:

O, N, F, Cl, Br, I, S, & P

Functional Group

• functional group: atom or group atoms in organic molecule that

always behaves the same way

• Adding functional group changes chemical & physical properties in specific ways– depends on type functional group added

Intermolecular Forces

• Determine Boiling Point & Solubility• Van der Waals or dispersion: weakest

– nonpolar molecules

• Dipole-dipole: intermediate strength– molecule has atoms with different

electronegativities– atomsatoms not not arranged symmetrically

• Hydrogen bonding: strongest – molecules contain H bonded to F, O, or N

Functional Groups

1.Halocarbons

2.Alcohols

3.Ether

4.Aldehydes

5.Ketones

6.Carboxylic Acid

7.Ester

8.Amines9.Amide

10.Amino Acid

Halocarbons/Halogens/Organic Halides

• One (or more) hydrogen atoms in alkane is replaced with halogen atom

(F, Cl, Br, or I)

• No longerNo longer hydrocarbons! • called halocarbons, alkyl halides or organic

halides

Naming Halides

• figure out backbone name

• prefixes specify substituent:

fluoro, chloro, bromo, iodo

• use di, tri, tetra – if more than one same thing

• tell location(s) of halogen(s)– state # C attached to in backbone

CH3Cl CH3CHFCH3

H H–C–Cl H

chloromethane

H H HH–C–C–C–H H F H

2-fluoropropane

C3H7F

Naming Halides

CH3CCl2CHClCH3 C4H7Cl3

H Cl Cl H H

H – C C – – C C – – C C – – CC – H H Cl ClCl Cl H

2,2,3-trichlorotrichlorobutanebutane

Ranking Halogens

• If more than 1 kind halogen atom present – name them alphabetically

• # C’s so lowest number goes to halogen alphabetically first

Different Halogens

Chlorine 1st alphabetically: determines numbering

4 3 2 1

2-chloro-4-fluoro-3-iodobutane

BrCH3CH2CHCHCH3

I

Name:

3-bromo 2-iodo pentane

F ClHCCH F Cl

1,1-dichloro-2,2-difluoroethane

Properties of Halocarbons

• alkane & alkyl halide of similar size & shape:– alkyl halide has higher bp & higher density

Why?

• CH4: bp = -162C

density = 0.423 g/ml

• CH3Cl: bp = -24C

density = 0.911 g/ml

Stronger intermolecular forcesStronger intermolecular forces

1.516155CH3CH2CH2CH2CH2I

1-iodopentane

1.218130CH3CH2CH2CH2CH2Br

1-bromopentane

0.882108CH3CH2CH2CH2CH2Cl

1-chloropentane

0.79163CH3CH2CH2CH2CH2F

1-fluoropentane

0.62636CH3CH2CH2CH2CH3

pentane

Density

(g/ml)

Boiling Point

(C)

Inc Inc

Uses of Alkyl Halides

• Cleaners & solvents

• Examples: – Teflon & PVC’s – Refrigerants (used to be chlorofluorocarbons-

now hydrofluorocarbons)

Halogen Derivatives

• CH3Cl = local anesthetic (chloromethane)

• CHCl3 = solvent, general anesthetic (trichloromethane)

• CHI3 = antiseptic (tri-iodomethane)

• CCl4 = dry cleaning solvent (tetrachloromethane)

• CF2Cl2 = refrigerant (dichloro,difluoromethane)

• Fluorocarbons = teflon, lubricants, synthetic blood

• Chlorofluorocarbons = aerosol propellants,

refrigerants

Table R

• General Formula halocarbons: R-X

– R represents entire hydrocarbon part of molecule

– X represents halogen (F, Cl, Br, or I)

Alcohols

• OH group replaces H in hydrocarbon

• OH group called: hydroxyl group

HHCH H

OHOH HHCOHOH H

Alcohols are non-non-electrolytes!

• hydroxyl group = hydroxide ion of bases - does not form ions in water!

• hydroxyl group is polar – alcohols soluble in water

Naming AlcohOLOLs

• Based on alkane name

• Name parent chain– drop –e ending & add –olol

• If parent chain has 3+ C’s, # which C

OH group(s) attached to

Naming

H H H HHCCCCH OH H H H

1-Butanolbp = 100C

H H H HHCCCCH H OH H H

2-ButanolBp = 115C

Note: Never more than one OH group per C

More than 1 hydroxyl group

• Prefixes di-, tri-, tetra- – used before -ol ending – tell # of hydroxyl groups

Classifying Alcohols

• By # of hydroxyl groups

–Monohydroxy: 1 hydroxyl group

–Dihydroxy: 2 OH groups

–Trihydroxy: 3 OH groups

• By position of each hydroxyl group on main carbon chain

Monohydroxy Alcohols

• PrimaryPrimary: OH group attached to end C of chain or branch

• SecondarySecondary: OH group attached to chain C bonded to 2 other C’s

• TertiaryTertiary: OH group attached to C at branch point (C bonded to 3 other C’s)

H H H HH-C-C-C-C-O-H H H H H

1-butanol(primary)

H H H HH-C-C-C-C-H H H O H H

2-butanol(secondary)

H H-C-H H HH-C-C-C-H H O H H

2-methyl 2-propanol(Tertiary)

H HH-C─C-H O O H H

H H HH-C─C─C-H O O O H H H

Dihydroxy Trihydroxy

Properties of Alcohols

• Contain: H bonded to O atom

– Hydrogen Bonding Hydrogen Bonding

• Alcohols: higher bphigher bp than corresponding alkane

• ‘‘Like dissolves LikeLike dissolves Like’’ – Alcohols tend to be very soluble in water

OR

H

OR

H-

++

+

-

H-bond

Which compound has the highest boiling point?

A. CH4

B. C2H6

C. C3H8

D. C3H7OH

Correct response = D

Table R

• General Formula Alcohols: ROH• R represents entire hydrocarbon part of

molecule

• OH is hydroxyl group

Ethers

• General formula ROR – where R may or may not be same as R

• R and R are hydrocarbon branches

• O is oxygen bridge

• Ethers are not linear – they are bent, like water

Properties of Ethers

• PurePure ether: no hydrogen bonding – weak dipole-dipole interactions

– bent, like H2O

• Ethyl ether once used as anesthesia

Properties of Ethers

• Compared to alkanes (same # C’s):– Higher bp’s than similar alkanes– More soluble in water than alkanes

• Compared to alcohols (same # C’s):– Lower bp’s than similar alcohols– Much less soluble in water than alcohols

Naming Ethers

• If both hydrocarbon branches are identical:– name the branch (once) & add the word

ether

• If 2 branches are different: – list them in alphabetical order followed by

the word ether

H HHCOCH H H

Methyl Ether

H H H H H HHCCCOCCCH H H H H H H

Propyl Ether

H H H HHCOCCCH H H H H

Methylpropyl Ether