Hybridization PDF / PPT

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Lecture No. 03



• Hybridisation

• SP2

• Sp3

• Sp

• Bong angles

• Geometry


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Learning Objectives

At the end of this lecture, student will be able to

• Explain different types of hybridisation

• Relate hybridisation to geometry of molecules


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• Hybrid orbital- An orbital formed by the combination of two or
more atomic orbitals

• Hybridization- The combination of atomic orbitals of different types

• Number of hybrid orbitals formed is equal to the number of atomic
orbitals combined

• sp3 Hybrid Orbitals—Bond Angles of Approximately 109.5°

• Combination of the 2s atomic orbital and three 2p atomic orbitals
forms four equivalent sp3 hybrid orbitals

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• Mixing of orbitals

• To attain equal energy and stability

• Sp3

• Sp2

• Sp

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Sp3 hybridization

• Axes of the four sp3 hybrid orbitals are directed toward the corners
of a regular tetrahedron

• sp3 hybridization results in bond angles of approximately 109.5°

• Each sp3 orbital has 25% s-character and 75% p-character

• Because those are the percentages of the orbitals combined when
constructing them

• one 2s orbital, three 2p orbitals

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Sp3 Hybridisation Contd…


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Sp3 Hybridisation Contd…

The four orbitals are directed toward the
corners of a tetrahedron, causing each
bond angle to be 109.5°

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Sp2 hybridization

• Bond angles of approximately 1200

• combination of one 2s atomic orbital wave function and two 2p
atomic orbital

• forms three equivalent sp2 hybrid orbital

• Axes of the three sp2 hybrid orbitals lie in a plane and are directed
toward the corners of an equilateral triangle

• three equivalent sp2 orbitals along with the remaining unhybridized
2p atomic orbital

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Sp2 hybridization

• Each sp2 orbital has 33% s-character and 67% p-character

• one 2s orbital, two 2p orbitals


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Borane (BH3)
• Sp2 hybridization

• Exception to octet rule

• According VSEPR theory, trigonal planar with bond angle 1200


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Sp2 Hybridisation


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Sp2 Hybridisation Contd…


Trigonal planar carbon, 120o
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sp hybridization

• Bond angle of approximately 1800

• combination of one 2s atomic orbital and one 2p atomic orbital

• produces two equivalent sp hybrid orbital

• axes of the unhybridized 2p atomic orbitals are perpendicular to
each other and to the axis of the two sp hybrid orbitals

• Each sp orbital has 50% s-character and 50% p-character


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Sp Hybridisation


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Sp Hybridisation


Linear molecule


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• Sp3, sp2 and sp hybridisation

• Example for Sp3 hybridisation is methane and ethane

• Four Sp3 hybridized orbitals

• All bonds are sigma bonds

• Geometry of methane is tetrahedral and bond angle is 109.5°

• Example for sp2 hybridisation is ethene

• Three Sp2 hybridized orbitals

• One unhybridised p- orbital oriented perpendicular to the plane

• One π bond is formed
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Summary Contd…

• Geometry of ethene is trigonal and bong angle is 120°

• Example for sp hybridisation is ethyne

• Two Sp hybridized orbitals

• Two unhybridised P- orbitals oriented pependicular to the plane

• Two π-bonds are formed

• Geometry of ethyne is linear and bond angle is 180°


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• Has two linear sp carbon atoms (C2 and C3)

• Two trigonal sp2 carbon atoms (C5 and C6)

• Two tetrahedral sp3 carbon atoms (C1 and C4)


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Thank You