Transcript Hydrocarbon Derivatives:

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 of molecule in specific ways
– changes depend on type functional group added
Intermolecular Forces
• determine boiling point & solubility
• van der Waals (dispersion): weakest
– nonpolar molecules
• dipole-dipole: intermediate strength
– molecule has atoms with different
electronegativities
– molecules not symmetrical
• 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
see Table R
Halocarbons/Halogens/
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
Table R
• general formula halocarbons:
R-X
– R represents entire hydrocarbon part of
molecule
– X represents halogen (F, Cl, Br, or I)
Naming Halides
• figure out backbone name
• prefixes specify halogen:
fluoro, chloro, bromo, iodo
• di, tri, tetra if more than one same halogen
• state # C attached to in backbone
– gives location(s) of halogen(s)
0
Note: follow same basic rules learned so far
• # chain so halogen has lowest #
• halogen # takes precedent over multiple bonds and
branches
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
• lowest # goes to halogen alphabetically
first
•
Different Halogens
4
3
2
1
chlorine 1st alphabetically: 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 IMF
• CH4: hydrocarbon (non-polar)
bp = -162C
density = 0.423 g/ml
• CH3Cl: halogen (polar)
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, plastics
• examples:
– Teflon & PVC’s
– refrigerants (used to be chlorofluorocarbonsnow 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
Alcohols
• OH group replaces H in hydrocarbon
• OH group called hydroxyl group
H

HCH

H
OH
H

HCOH

H
Table R
• general formula Alcohols:
ROH
• R represents entire hydrocarbon part of
molecule
• OH is hydroxyl group
alcohols are non-electrolytes!
• hydroxyl group (hydroxide ion of bases)
- does not form ions in water! (no metal like bases)
• hydroxyl group is polar
– alcohols soluble in water
Naming AlcohOLs
• based on alkane name
• name parent chain
– drop –e ending & replace with –ol
• # C OH group(s) attached to (if 3+ carbons)
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
• use prefixes di-, tri-, tetra– put before -ol ending
– tell # of hydroxyl groups
Classifying Alcohols
1. by # of hydroxyl groups
2. by position of each hydroxyl
group on main carbon chain
# hydroxyl groups
• monohydroxy alcohol: 1 hydroxyl group
• dihydroxy alcohol:
2 OH groups
• trihydroxy alcohol:
3 OH groups
position of hydroxyl group:
monohydroxy alcohols
• primary alcohol:
-OH group attached to end C of chain
• secondary alcohol:
-OH group attached to C bonded to 2 other C’s
• tertiary alcohol:
-OH group attached to C at 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: higher bp than corresponding alkane
• ‘like dissolves like’
– alcohols tend to be very soluble in water
R
R
-
O
H
+
O
H
H-bond
+
-
Which compound has the
highest boiling point?
A.
B.
C.
D.
CH4
C 2H 6
C 3H 8
C3H7OH
Correct response = D
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 since polar
– bent, like H2O
• ethyl ether once used as anesthesia
Properties of Ethers
• compared to alkanes with same # C’s:
– higher bp’s than alkanes
(ethers have greater mass due to O)
– more soluble in water than alkanes
(ethers are polar, alkanes are not)
• compared to alcohols with same # C’s:
– lower bp’s than similar alcohols
(ethers don’t have H-bonds, alcohols do)
– much less soluble in water than alcohols
(ethers less polar than alcohols)
Naming Ethers
• if both hydrocarbon branches identical:
– name branch only once followed by ether
• if 2 branches are different:
– list names alphabetically followed by ether
H
H
HCOCH
H
H
methyl ether
(correct on Table R)
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