1. Sigma and Pi Bonding
SWBAT: Draw Quantum Mechanical models of molecules using sigma and pi bonding

2. Number of hybrid orbitals formed Number of atoms bonded to the C
Carbon Hybridization
Type of hybrid
Atomic orbitals used
Number of hybrid orbitals formed
Number of atoms bonded to the C
Aufbau Chart
sp3
s, p, p, p 4
sp2
s, p, p 3 sp
s, p 2

3. Number of hybrid orbitals formed Number of atoms bonded to the C
Carbon Hybridization
Type of hybrid
Atomic orbitals used
Number of hybrid orbitals formed
Number of atoms bonded to the C
Aufbau Chart
sp3
s, p, p, p 4
sp2
s, p, p 3 sp
s, p 2

4. sp3 Hybridization

5. Number of hybrid orbitals formed Number of atoms bonded to the C
Carbon Hybridization
Type of hybrid
Atomic orbitals used
Number of hybrid orbitals formed
Number of atoms bonded to the C
Aufbau Chart
sp3
s, p, p, p 4
sp2
s, p, p 3 sp
s, p 2

6. sp2 Hybridization
C2H4

7. Number of hybrid orbitals formed Number of atoms bonded to the C
Carbon Hybridization
Type of hybrid
Atomic orbitals used
Number of hybrid orbitals formed
Number of atoms bonded to the C
Aufbau Chart
sp3
s, p, p, p 4
sp2
s, p, p 3 sp
s, p 2

8. sp Hybridization
C2H2

9. Covalent Bonds
The formation of a covalent bond involves the overlapping of half filled atomic orbitals
The two different categories of covalent bonds are Sigma and Pi covalent bonds

10. Sigma bonding
Bond is formed by the axial overlapping of half filled atomic orbitals
The electron cloud formed is cylindrically symmetrical about inter nuclear axis
The electrons constituting sigma bonds are called sigma electrons

11. 3 Types of Sigma Bonding
s-s overlap
s-p overlap
p-p overlap

12. sp-overlaps
Example: CH4

13. Strength of Sigma Bonds
The strength of three types of sigma bonds varies as follows
p-p > p-s > s-s
A p-p overlap is greater than an s-s overlap allowing it to be stronger

14. Pi Bonding
This type of covalent bond is formed by the lateral or sidewise overlap of the atomic orbitals
The orbital overlap takes place in a way that their axes are parallel to each other but perpendicular to the internuclear axis
The pi bond consists of two charge clouds above and below the plane of the atoms involved in the bond formation
The electrons involved in the p bond formation are called pi electrons

15. Pi Bonding

16. Sigma and Pi Bonding
Sigma bonds are stronger than pi bonds (greater overlap between orbitals occurs)
Pi bonding between the two atoms is formed only in addition to a sigma bond (Sigma first then Pi)
Atoms rotate around sigma bonds but not pi bonds
The shape of the molecule is controlled by the orientations of sigma bonds around the central atom. Pi bonds are superimposed on sigma bonds.

17. Sigma and Pi bonding with Oxygen (O2)
1s22s22p4
s orbitals are filled and the 2px orbital is filled
The 2py and 2pz orbitals are partially filled
An O=O molecule has one sigma and one pi bond (connect both lobes of a p orbital for a pi bond…. Draw two lines for one pi bond)

18. Oxygen (O2)
Nitrogen (N2)

19. Carbon Hybridization Review