Page 8 - Pharm.Org.Chem-I 02-06-05-101

3- Coordination Bond (Semi-ionic Bond)

F Acceptor F F
FB has vacant orbital FF

F F F B
-B

N +N H N H

H Donor H H
H H H
H has lone pair

of electrons

11

4- Hydrogen Bond (H.B.)

Types of Hydrogen Bonds:

a- Intermolecular hydrogen bond

− + − +
OH
OH

HH

H.B. is due to electrostatic
attraction between + and −

Association hydrogen bond leads to increase in boiling point
Ethanol (C2H5OH, 780C), and diethyl ether (C2H5-O-C2H5, 320C)

12

6