Or functional groups. Functional groups Functional groups are parts of molecules that result in characteristic features. Many functional groups exist,

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