Transcript Hydrocarbon Derivatives:

Hydrocarbon Derivatives:
Halocarbons, Alcohols, & Ethers
Hydrocarbons
• Contain only carbon & hydrogen
• But 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
– atoms 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. Amines
9. Amide
10.Amino Acid
Organic Halides
• One (or more) hydrogen atoms in alkane
is replaced with halogen atom
(F, Cl, Br, or I)
• No 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
H

H–C–Cl
H
chloromethane
CH3CHFCH3
H H H
  
H–C–C–C–H
 

H F H
2-fluoropropane
C3H7F
Naming Halides
CH3CCl2CHClCH3
H Cl H H
H–C–C–C–C–H
H Cl Cl H
2,2,3-trichlorobutane
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
4
3
2
1
Chlorine is 1st alphabetically, so it determines
numbering:
2-chloro-4-fluoro-3-iodobutane
Name:
Br
CH3CH2CHCHCH3
I
3-bromo 2-iodo pentane
F Cl
HCCH
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?
Stronger intermolecular forces
• CH4:
bp = -162C
density = 0.423 g/ml
• CH3Cl: bp = -24C
density = 0.911 g/ml
CH3CH2CH2CH2CH3
pentane
CH3CH2CH2CH2CH2F
1-fluoropentane
CH3CH2CH2CH2CH2Cl
1-chloropentane
CH3CH2CH2CH2CH2Br
1-bromopentane
CH3CH2CH2CH2CH2I
1-iodopentane
Boiling Point
(C)
36
Density
(g/ml)
0.626
63
0.791
Inc
108
0.882
130
1.218
155
1.516
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
H

HCH

H
OH
H

HCOH

H
Alcohols are nonelectrolytes!
• hydroxyl group = hydroxide ion of inorganic
bases
- does not form ions in water!
• The hydroxyl group is polar
– alcohols soluble in water
Naming AlcohOLs
• Based on alkane name
• Name parent chain
– Drop the –e and add –ol
• If parent chain has 3+ C’s, # which C
OH group(s) attached to
Naming
H H H H
HCCCCH
OH H H H
1-Butanol
bp = 100C
H H H H
HCCCCH
H OH H H
2-Butanol
Bp = 115C
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
• Primary: hydroxyl group attached to end
C of chain or branch
• Secondary: hydroxyl group attached to C
in chain bonded to 2 other C’s
• Tertiary: hydroxyl group attached to C at a
branch point (C bonded to 3 other C’s)
HHHH
H-C-C-C-C-O-H
HHHH
HHHH
H-C-C-C-C-H
HHO H
H
1-butanol
(primary)
2-butanol
(secondary)
H
H-C-H
H H
H-C-C-C-H
HO H
H
2-methyl 2-propanol
(Tertiary)
H H
H-C─C-H
O O
H H
H H H
H-C─C─C-H
O O O
H H H
Dihydroxy
Trihydroxy
Properties of Alcohols
• Contain: H bonded to O atom
– Hydrogen Bonding
• Alcohols have higher bp than
corresponding alkane
• ‘Like dissolves Like’
– Alcohols tend to be very soluble in water
R
R
-
O
H
+
O
H
+
-
Which compound has the highest
boiling point?
A.
B.
C.
D.
CH4
C 2H 6
C 3H 8
C3H7OH
Correct response = D
Table R
• General Formula Alcohols:
ROH
• R represents entire hydrocarbon part of
molecule
• OH is hydroxyl group
Ethers
• General formula
ROR
– 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
• Pure 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
H
HCOCH
H
H
Methyl Ether
H H H
H H H
HCCCOCCCH
H H H
H H H
Propyl Ether
H
H H H
HCOCCCH
H
H H H
Methylpropyl Ether