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 Groups1.Halocarbons2.Alcohols3.Ether4.Aldehydes5.Ketones6.Carboxylic Acid7.Ester8.Amines9.Amide10.Amino Acid

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)• Give location(s) of halogen(s)

– tell # 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

H Cl Cl H H

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

2,2,3-trichlorotrichlorobutanebutane

C4H7Cl3

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 is 1st alphabetically, so it 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

1.516155CH3CH2CH2CH2CH2I1-iodopentane

1.218130CH3CH2CH2CH2CH2Br1-bromopentane

0.882108CH3CH2CH2CH2CH2Cl1-chloropentane

0.79163CH3CH2CH2CH2CH2F1-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

• CHCl3 = solvent, general anesthetic

• CHI3 = antiseptic

• CCl4 = dry cleaning solvent

• CF2Cl2 = refrigerant

• 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 nonnonelectrolytes!

• hydroxyl group = hydroxide ion of inorganic 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 the –e and 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: hydroxyl group attached to end C of chain or branch

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

• TertiaryTertiary: hydroxyl group attached to C at a 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)22

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 have higher bphigher bp than corresponding alkane

• ‘‘Like dissolves Like’Like 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