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Organic Compounds
hydrocarbons (C,H) heteroatomic (O, N, P, S, X, etc.)
aliphatic (fatty) aromatic (pleasant smelling)
alkane alkene alkyne cyclic
C C C CC C
or functional groups
Functional groups
• Functional groups are parts of molecules that result in characteristic features.
• Many functional groups exist, we will focus on about 4.
Organic compounds having functional groups
• Alcohols• Carboxylic acids• Amino acids• carbohydrates
1. Alcohols
• a class of organic compounds with an –OH (hydroxyl ) functional group.
• thus R-OH is the formula (The symbol “R” is used to represent any carbon chains or rings).
Alcohols• condensed structural IUPAC
commonformula formula name name
H – C – O – H
H
H
CH4O methanol Methyl alcohol
C2H6O H – C – C - O – H
H
H H
Hethanol Ethyl alcohol
Alcohols
• condensed structural IUPAC commonformula formula name name
HC2H6O2 ethanediol Ethylene glycol
C3H8O3 propanetriol glycerol
H – C – C – H
OH OH
H
H – C – C - C – H
H
OH OH
H H
OH
Naming alcohols
• For IUPAC:–drop the -e ending of the parent
alkane name; add the ending -ol.–Ethane ethanol
H – C – C - O – H
H
H H
H
Naming alcohols
• Alcohols containing 2, 3, and 4 of the -- OH groups are named diols, triols, and tetrols respectively.
H – C – C - C – H
H
OH OH
H H
OH
propanetriol
Naming alcohols
• Common names:–name the alkyl group, then followed
by the word alcohol.–One carbon alcohol = methyl
alcohol
H – C – O – H
H
H
Properties of alcohols
• Much like water, alcohols are capable of forming hydrogen bonding between molecules. This means–they will boil at a higher temp. than
alkanes with a comparable number of C atoms.–Alcohols of up to 4 carbons are
soluble in water in all proportions.
2. Carboxylic acids
• Functional group: - COOH or (carboxyl group)
• General formula: R-COOH • weak acids (ionize slightly)
- C – OH
O
Carboxylic acids
• Named by replacing the -e ending of the corresponding alkane name with -oic and followed by the word acid• methanoic acid; ethanoic acid.
Carboxylic acids
• condensed structural IUPAC commonformula formula name name
CH2O2 methanoic acid
Formic acid
C2H4O2 Ethanoic acid Acetic acid
H - C – OH
O
H – C -C – OH
O H
H
3. Amino acids
• Functional groups: - NH2 (amino) and
- C – OH
O(carboxyl).
Amino acids
• condensed structural commonformula formula name
C2H5NO2 glycine
alanine
H2N - C - C – OH
O
H
H
H2N - C - C – OH
O H
CH3
C3H7NO2
4. Carbohydrates
• The functional group is
or
- C –
O(carbonyl)
-C – H
O
(aldehyde).
Carbohydrates
fructose
HO – C – H
C = O
H – C – OH H – C – OH
H – C – O H
H – C – OH H
H
HO – C – H
H – C – OH
H – C – OH H – C – OH
H – C = O
H – C – OH H
Glucose, C6H12O6
Hydrophilic groups
• Hydrophilic means “water loving.”• Hydrophilic groups are electrically polarized.
This makes the substances including a hydrophilic group soluble in polar solvents like water.
• Examples: - OH, - COOH, - NH2
Hydrophobic groups
• Hydrophobic means “water hating.” Hydrophobic groups are not electrically polarized. Therefore, hydrophobic substances are not soluble in water but soluble in non-polar solvents like benzene.
• Examples: alkanes, ethylene, acetylene, CCl4, oils, and fats.
Hydrophilic and hydrophobic groups
• The common soap is the Na salt of stearic acid. Its formula is: CH3(CH2)16COONa.
• When it dissolves in water, it produces Na+ and CH3(CH2)16COO- ions.
–CH3(CH2)16 COO-Hydrophobic tail Hydrophilic head
Hydrophilic and hydrophobic groups
oil oil
MicelleHydrophobic tails dissolve oil. Hydrophilic heads stay away from oil but attracted by water molecules. So, the oil is washed away by soap and water.
Micelle
oil
References
• www.chalkbored.com/lessons/chemistry-12/functional-groups.ppt
• www.cottonchemistry.bizland.com/.../Chapter%2023%20Functional%20Groups.ppt
• http://www.hastings-on-hudson-firedept.org/F500/images/f500_micelle.jpg