types of bonds and intermolecular bonding

1. Types of Bonds
By
Mr. Ganesh Bhadole
M Pharm I st
University Department of Pharmaceutical Sciences,
R.T.M. Nagpur University, Nagpur-440033
2017-2018

2. CONTENT
• Introduction
• The octet rule
• Types of Chemical Bonds
• Intermolecular forces of bonding
• References

3. INTRODUCTION
Chemical Bonds-
• Force of attraction that holds Two or more elements together.
• Has a significant effect on chemical and physical properties
of compounds
• involves the valence electrons
Valence Electrons – the electrons in the outermost
energy level of an atom
11-11-2017 3

4. The Octet Rule –
• Atoms will combine to form compounds in order
to reach eight electrons in their outer energy level.
• Atoms with less than 4 electrons tend to lose
electrons.
• Atoms with more than 4 electrons tend to gain
electrons.
• Be aware that there are some exceptions!

5. Types of Chemical Bonds
• IONIC BOND
• COVALENT BOND
• METALLIC BOND
• CO-ORDINATE BOND
11-11-2017 5

6. IONIC BOND –
Bond formed between two ions by the transfer of
electrons from a metal to a non-metal.
-Metals give up valence
electrons (to see 8 in
lower shell.
-Nonmetals
receive electrons
(enough to see 8
valence e’s
The result is the formation
of positive and negative
ions that are bonded by
electrostatic attraction11-11-2017 6

7. 11-11-2017 7

8. Ionic Compounds
-High melting and boiling pts.
-Crystal lattice
-Form electrolytes when dissolved in water (conduct
electricity)
-solid at room temp.
Examples
11-11-2017 8

9. COVALENT BOND
bond formed by the mutual sharing of electrons between
two or more non-metals.
Example.
Oxygen Molecule (O2)
Oxygen Atom Oxygen Atom
11-11-2017 9

10. 11-11-2017 10

11. Ionic Compounds Covalent Compounds
High m.p., b.p Low m.p., b.p.
Solid at room temp Solid, liquid, gas at room
temp.
Dissolved in water:
electrolytes
Dissolved in water: non-
electrolytes
11-11-2017 11

12. 11-11-2017 12
Two types of bonds are formed
• Either sigma bonds • Or pi bonds
Sigma bonds
Three possible ways for a sigma bond to be formed-
• Overlapping of two S-orbital
• Overlapping of an S and a P- orbital
• Head to head overlapping of two P- orbital

13. 11-11-2017 13

14. 11-11-2017 14
Pi bonds
• The side to side overlapping of two P-orbital.
• Electrons in this bond are delocalized
• The electron density is above and below the plane of the
sigma bond.
• These bonds make a compound reactive
• Example in alkenes with the c-c double bond.

15. Types of Covalent Bonds
• Different covalent bond types share a different
number of electrons.
+
+
+
+
+
++
+
++
-
-
-
-
-
-
-
-
+
+-
-
+
+
+
+
+
+
++
+
++
-
-
-
-
-
-
-
+
-
+
+
+
+
++
+
++
-
-
- -
+
+
+
+
+
++
+
++
-
-
-
-
-
-
-
-
+
- - +
+
+
+
+
++
+
++
-
-
-
-
-
-
-
+
+
+
+
+
++
+
++
-
-
-
-
-
-
-
Single Bonds
Share 2
Electrons
Double Bonds
Share 4
Electrons
Triple Bonds
Share 6
Electrons
Water (H2O) Carbon Dioxide (CO2) Nitrogen (N2)
11-11-2017 15

16. NON-Polar covalent bonds
• Electrons shared evenly in the bond.
• Electronegativity difference is zero.
Examples: bonds between same non-metals.
Between identical atoms
Diatomic molecules
Polar covalent bond
• Electrons unevenly shared
• Electronegativity difference greater than zero
Examples.:
• HCl
• CH4
• CO2
• NH3 11-11-2017 16

17. METALLIC BOND
• Force of attraction between positively charged metal ions
and the electrons in a metal.
• Formed between atoms of metallic elements
• Electron cloud around atoms
• Good conductors at all states, lustrous, very high melting
points
• Examples; Na, Fe, Al.
Metallic Bond,
A Sea of
Electrons
11-11-2017 17

18. Metallic bonds forms alloys
which is a solution of a metal in a metal.
Examples are
Brass – mix of Cu and Zn
Bronze – mix of Cu and tin, or Al.
11-11-2017 18

19. 11-11-2017 19
CO-ORDINATE (DATIVE COVALENT)
BOND –
• A bond is formed by two atoms sharing a pair of
electrons.
• The atoms are held together because the electron pair is
attracted by both of the nuclei.
• Example –
• 1.Ammonium Ion

20. 11-11-2017 20
2. Aluminium Tetrachloride
3. Hydroxonium Ion

21. 11-11-2017 21
Intermolecular Forces of bonding :
Forces between molecules or ions they are generally
weak forces of bonding.
Responsible for the states of matter.
• Hydrogen Bonding
• Ion-dipole
• Dipole-dipole
• Dipole-Induced Dipole
• Induced Dipole- Induced Dipole

22. 11-11-2017 22
To study the intermolecular forces of bonding
we should know the following terms
Dipolar molecule-
A substance with both a positive and negative ends.
Dipole- Separation of charge within molecules
Inductive forces-
Arise from distortion of the charge cloud induced by
the presence of another nearby molecule.
Distortion arises from the electric field produced by the
charge distribution of the nearby molecule.

23. 11-11-2017 23

24. 11-11-2017 24
References:
1. Morrison R.T., Boyd R.N., ” Text Book Of Organic
Chemistry” published by Pearson, sixth edition Page
No: 40-41.
2. Bahl A., Bahl B.S., “Text Book Of Organic Chemistry”
published by S. Chand, 22th edition Page No: 88-94.

25. 11-11-2017 25
THANK
YOU….