Download alkohol-eter

25/05/2017
1
Alcohols and Ethers can be regarded as
derivatives of water in which one or two of the
H atoms has been replaced by an alkyl group
Methanol, CH3OH
Water, H2O
H
O
0.96 Ao
o
0.96 A
H C
H
O
H
H H
104.5o
108.5o
Methoxymethane, CH3OCH3
1.43 Ao
H C
O
C H
H H H H
109.5o
111.7o
1.43 Ao
1.10 Ao
Saturated
molecules
are sp3
hybridized



Rantai utama adalah rantai karbon
terpanjang yang mengandung –OH
Nama alkohol dinamai dengan nama alkana
dengan mengganti akhiran -a dengan -ol
Posisi gugus –OH diberi nomor

CH3OH
CH3CH2OH
CH3CH2CH2OH

CH3CH CH3


: metanol = metil alkohol
: etanol = etil alkohol
: 1-propanol = n-propil alkohol
: 2-propanol = isopropil alkohol
OH

: 2-metil-1-propanol = isobutil alkohol
 Letak
gugus -OH menunjukkan derajat
alkoholnya



ALKOHOL 1
ALKOHOL 2
ALKOHOL 3
CH3
H
H3C C OH
H3C C OH
H
H
CH3
H3C C OH
CH3
Secondary (2o) Alcohol
Primary (1 ) Alcohol
Tertiary (3o) Alcohol
o
Polyhydroxy alcohols are alcohols that
possess more than one hydroxyl group
CH2
HO
CH2
HO
CH2
CH CH2
HO
OH
1,2,3-Propanetriol (glycerol)
OH
1,2-Ethanediol (ethylene glycol)
CH3
CH CH2
HO
OH
1,2-Propanediol (propylene glycol)
Extremely Toxic
Harmless
H
R
O 
H

H
O
O
R
Electronegativity of
oxygen causes an
unsymmetrical
distribution of charge
Methanol and Ethanol
are classed as Polar
Molecules (Hydrophilic)
Alcohols are found to have
much higher boiling point than
those of alkanes or haloalkanes
in homologues series
H
H
H
O 
H

H
O
O
H
They are Soluble in Water
Hydrogen Bonding
R
Ethanol
H H
1-Pentanol
H C C O
H C C C C C O
H H
Hydrophilic end
H H H H H
H
H H H H H
H
Hydrophobic end
As R-group increases in size, so does the solubility
in non-polar solvents
As the number –OHs increases so does solubility in
water
Bpt increase with chain length and number of –OHs
Ethanol, CH3OH
-Drinking Alcohol
- 50% Ethanol is flammable
Methanol, CH3OH
- Solvent in varnishes, paint
- Racing Car Fuel (easy to put
out flames)
- Highly Toxic
Alcohols are very weak Acids
H
R O H
  
Alcohol
H
+
R O
Alkoxide
O H
Relative Acidity ; H2O > ROH > R
2 CH3CH2OH + 2 Na
2 CH3CH2
Vigorous Reaction
H O H
C C H > RH
O
Na
+ H2
 Hidrasi
katalisis dari alkena
(proses industri)
 Fermentasi gula menggunakan katalis
enzim
H
H
H
H2O
H H3PO4 , 300C
CH3CH2OH
 Beer,
3-9%
 Wine, 11-13%
 Whisky, 40-45%
 Vanilla Extracts, 35%
 Night Nurse, 25%
 Listerine, 25%
Phenols are stronger acids than alcohols
OH
pKa = 18
H O
O
OH
pKa = 10
O
O
Resonance Stabilised Phenoxide anion
ETHERS, RO-OR
CH3CH2
O CH2CH3
Diethyl Ether
Methoxy group
H3C O
Ethoxy group
CH3CH2 O
H3CO
Methoxycyclohexane
O
1-Propoxypropane
OCH 3
Methoxybenzene (anisole)
O
Furan
O
Tetrahydrofuran (THF)
Cyclic Ethers
O
Pyran
 Boiling
point are similar to alkanes
 No H-bonding to one another
 Soluble in water (H-bonding to water)
 Polar
 Flammable – Ether can cause flash
fires
 Low Reactivity – Make Good Reaction
Solvents