Chemical Bonding and Molecular Structure Part - 13 | Class 11th

      ·      sp³d Hybridisation: It is the process of inter mixing of one s-orbital, three p-orbitals and one d-orbital to form five new orbitals having equivalent energy and shape. The 5 new orbitals formed are called sp³d hybrid orbitals. These are directed to the five corners of a regular trigonal bipyramid with bond angles 120⁰ and 90⁰.

        

     In PCl₅, three P-Cl bonds lie in one plane, at an angle of 120⁰. These three bonds are called equatorial bonds. The other two P-Cl bonds lie one above and one below this plane. They are called axial bonds. The axial bond pairs suffer more repulsion from the equatorial bond pairs. So, the axial bond length is greater than the equatorial bond length. So PCl₅ is highly unstable and is very reactive.

             

     ·       sp³d² Hybridisation: It is the process of inter mixing of one s-orbital, three p-orbitals and two d-orbitals to form six new orbitals having equivalent energy and shape. The 6 new orbitals formed are called sp³d² hybrid orbitals. These are directed to the six corners of a regular octahedron with bond angle 90⁰. For example, formation of SF₆.