1. Hybridization is a model that explains how atoms combine orbitals to form bonds in molecules. It involves mixing atomic orbitals of similar energies to form new hybrid orbitals used in bonding. 2. There are several types of hybridization depending on how many orbitals mix, including sp, sp2 and sp3 hybridization. This determines the geometry and bond angles of the molecule. 3. Hybridization also influences bond properties like bond length and bond strength. Polar bonds form when there is a large difference in electronegativity between the atoms, and the overall polarity of a molecule depends on whether individual bond dipoles cancel or reinforce.

1. HYBRIDIZATION IN ORGANIC
COMPOUNDS
Dr. Rajasekhar Reddy
K L COLLEGE OF PHARMACY,
KLEF DEEMED TO BE UNIVERSITY

2. • The atomic structures, from the Periodic Table, of atoms such as C, N, and O do not adequately
explain how these atoms use orbitals to form bonds
• A hybridization model has therefore been developed in order to explain real structures, for example
how all of the bond lengths and angles are equivalent in CH4 (methane)
HYBRIDIZATION:

3. HYBRIDIZATION:
Definition:
The phenomenon of mixing up of atomic orbitals of similar energies and formation of equivalent
number of entirely new orbitals of identical shape and energy is known as "hybridization" and the new
orbitals so formed is called as "hybrid orbitals".
Important points for understanding the hybridization:
i. The number of hybrid orbitals generated is equal to the number of pure atomic orbitals that
participate in hybridization process.
ii. Hybridization concept is not applicable to isolated atoms. It is used to explain the bonding scheme
in a molecule.
iii. Covalent bonds in polyatomic molecules are formed by the overlap of hybrid orbitals or of hybrid
orbitals with unhybridized ones.

4. Types of Hybridization
• Based on the types of orbitals involved in mixing, the hybridization
can be classified as
• sp Hybridization
• sp2 Hybridization
• sp3 Hybridization
• sp3d Hybridization
• sp3d2 Hybridization
A given number of atomic orbitals hybridize to form
an
equivalent number of hybrid orbitals.
• One 2s orbital and three 2p orbitals form four sp3 hybrid orbitals.
• One 2s orbital and two 2p orbitals form three sp2 hybrid orbitals.
• One 2s orbital and one 2p orbital form two sp hybrid orbitals.

5. Types of Hybridization

6. Carbon would form two different types of bonds: three with 2p orbitals and one with a 2s
orbital. But experimental evidence points to carbon forming four identical bonds in
methane.

8. Consider water:
Facts: O-H bond lengths are equivalent; lone pairs are equivalent

9. Looking at the atoms that make H2O
Each H atom has a single electron and is 1s1
The O atom has 8 total electrons and is 1s2 2s2 2px2 2py1 2pz1
The two lone pairs on O (2s2 and 2px2) here are not the same but
they are equivalent in H2O, therefore we cannot use this atomic
structure of O to make water – we have to modify it

10. Manipulating the Atomic Orbitals on O
We can translate the electronic structure to make it easier to see

11. The Hybridization Model for O
The lone pairs are not the same here so we need to modify the
ground state picture to better match how O bonds in H2O:

12. Building the Model
The blue horizontal lines represent the orbitals and the red arrows
are the electrons occupying these orbitals

13. Building the sp3 Model
Here we manipulate by mixing (hybridizing) the s and p orbitals
from the ground state configuration to give four sp3 orbitals:

14. The sp3 Model
Some things to notice about sp3 orbitals:

15. Populating the Orbitals
We now have two equivalent lone pairs (sp3) and two half-filled
orbitals (sp3) that will make sigma bonds with H atoms in H2O

16. The sp3 model in H2O
Remember that these are atomic orbitals on O and that they
must overlap with 1s orbitals from H to give H2O

17. Hybrid orbital patterns
There are only three orbital patterns that you need to know in the
Organic Chemistry sequence

18. The sp3 picture for C, N and O
If there are no pi bonds, sp3 hybrid orbitals are used

19. The sp3 picture forCarbon
The four sp3 orbitals from C project to the four corners of a
regular tetrahedron

20. Examples of sp3 hybrid atoms
As examples, each of the C, N and O atoms in these molecules
are sp3 hybridized – all single bonds!

21. Orbitals of sp2 hybrid atoms
The sp2 picture has to accommodate a pi bond by leaving onep
orbital unchanged

22. Hybrid orbitals contribute to sigmabonds
Notice that the hybrid (sp2) orbitals go to make single (sigma)
bonds and the left over p orbital goes to the pi bond

23. Overlap of sp2 hybrid atoms
Two sp2 hybrid C atoms overlap in ethylene,H2C=CH2

25. Examples of sp2 hybrid atoms
As examples, each of the highlighted C, N and O atoms in these
molecules are sp2 hybridized – 1 pibond!

26. The sp hybrid picture
When two pi bonds are formed by a C or N atom, sp hybrid
orbitals are used

27. The sp hybrid orbitals : sigma bonds
Notice that the hybrid (sp) orbitals go to make single (sigma)
bonds and the left over p orbitals go to the pi bonds

28. The sp hybrid orbitals : alkynes
Notice that the hybrid (sp) orbitals go to make single (sigma)
bonds and the left over p orbitals go to the pi bonds

30. Examples of sp hybrid atoms
As examples, each of the highlighted C, N and atoms in these
molecules are sp hybridized – 2 pi bonds!

31. Examples of hybridization : 1
Which atom and hybridization pattern does this picture represent?

32. Examples of hybridization : 1 answer
Which atom and hybridization pattern does this picture represent?
sp2 hybrid Nitrogen

33. Examples of hybridization : 2
Which atom and hybridization pattern does this picture represent?

34. Examples of hybridization : 2 answer
Which atom and hybridization pattern does this picture represent?
sp hybrid Carbon

35. Examples of hybridization : 3
Which atom and hybridization pattern does this picture represent?

36. Examples of hybridization : 3 answer
Which atom and hybridization pattern does this picture represent?
sp3 hybrid Oxygen

37. Examples of hybridization : 4
Indicate the sp hybrid atom in the following molecule

38. Examples of hybridization : 4 answer
Indicate the sp hybrid atom in the following molecule

39. Examples of hybridization : 5
Indicate the sp3 hybrid atom in the followingmolecule

40. Examples of hybridization : 5 answer
Indicate the sp3 hybrid atom in the followingmolecule

41. Examples of hybridization : 6
Indicate the sp2 hybrid atoms in the followingmolecule

42. Examples of hybridization : 6 answer
Indicate the sp2 hybrid atoms in the followingmolecule

43. sp Hybridization
sp hybridization is observed when one s and one p orbital in the same main shell of an
atom mix to form two new equivalent orbitals. The new orbitals formed are called sp
hybridized orbitals. It forms linear molecules with an angle of 180°
• This type of hybridization involves the mixing of one ‘s’ orbital and one ‘p’ orbital
of equal energy to give a new hybrid orbital known as an sp hybridized orbital.
• sp hybridization is also called diagonal hybridization.
• Each sp hybridized orbital has an equal amount of s and p character, i.e., 50% s and
p character.

44. sp2 Hybridization
sp2 hybridization is observed when one s and two p orbitals of the same shell of an atom
mix to form 3 equivalent orbital. The new orbitals formed are called sp2 hybrid orbitals.
• sp2 hybridization is also called trigonal hybridization.
• It involves mixing of one ‘s’ orbital and two ‘p’ orbital’s of equal energy to give a new
hybrid orbital known as sp2.
• A mixture of s and p orbital formed in trigonal symmetry and is maintained at 1200.
• All the three hybrid orbitals remain in one plane and make an angle of 120° with one
another. Each of the hybrid orbitals formed has 33.33% s character and 66.66% ‘p’
character.
• The molecules in which the central atom is linked to 3 atoms and is sp2 hybridized have a
triangular planar shape.

45. sp3 Hybridization
When one ‘s’ orbital and 3 ‘p’ orbitals belonging to the same shell of an atom mix together
to form four new equivalent orbital, the type of hybridization is called a tetrahedral
hybridization or sp3. The new orbitals formed are called sp3 hybrid orbitals.
• These are directed towards the four corners of a regular tetrahedron and make an angle of
109°28’ with one another.
• The angle between the sp3 hybrid orbitals is 109.280
• Each sp3 hybrid orbital has 25% s character and 75% p character.
• Example of sp3 hybridization: ethane (C2H6), methane.

46. Bond Angle:

47. Bond Length and Bond Strength

48. Bond Lengths and Bond Strengths for Ethane, Ethylene and Acetylene

49. A Comparison of Carbon–Hydrogen
BondsThe length and strength of a C – H bond vary slightly depending on the
hybridization of the carbon atom.

51. Electronegativity and Bond Polarity:
• Electronegativity is a measure of an atom’s attraction for electrons in a bond.
• Thus, electronegativity indicates how much a particular atom “wants” electrons.

52. Electronegativity and Bond Polarity:
• Electronegativity values are relative, so they can be used for comparison purposes
only.
• When comparing two different elements, one is more electronegative than the
other if it attracts electron density toward itself.
• One is less electronegative—more electropositive—if it gives up electron density
to the other element.

53. Electronegativity and Bond Polarity:
• Electronegativity values are used as a guideline to indicate whether the electrons in
a bond are equally shared or unequally shared between two atoms.
• The bond is polar, or polar covalent. The bond is said to have a dipole; that is, a
separation of charge.
• The direction of polarity in a bond is often indicated by an arrow, with the head of
the arrow pointing toward the more electronegative element.

54. Electronegativity and Bond Polarity:
• Usually, a polar bond will be one in which the electronegativity difference between
two atoms is ≥ 0.5 units.
• The distribution of electron density in a molecule can be shown using an
electrostatic potential map.
• Electron-rich regions are indicated in red, and electron-deficient sites are indicated
in blue. Regions of intermediate electron density are shown in orange, yellow, and
green.

55. Polarity of Molecules:
• To determine whether a molecule has a net dipole, use the following two-step
procedure:
[1] Use electronegativity differences to identify all of the polar bonds and the
directions of the bond dipoles.
[2] Determine the geometry around individual atoms by counting groups, and
decide if individual dipoles cancel or reinforce each other in space.