HYBRIDISATION : HYBRIDISATION sp3
Slide 2 : Hybridization is an imaginary mixing process in which the orbitals of an atom rearrange to form new atomic orbitals called hybrid orbitals. In forming the hybrid orbitals, if possible, shared pairs of electrons will be promoted so that all electrons are unpaired. The promotion will occur between the s, p, d, and f orbitals in order to maximize the number of unpaired electrons
Slide 3 : In 1931, Linus Pauling proposed that the wave functions for the s and p atomic orbitals can be mathematically combined to form a new set of equivalent wave functions called hybrid orbitals.
The mathematical process of replacing pure atomic orbitals with
reformulated atomic orbitals for bonded atoms is called hybridization.
Slide 4 : Hybridization – mixing of two or more atomic
orbitals to form a new set of hybrid orbitals Number of hybrid orbitals is equal to number ofpure atomic orbitals used in the hybridizationprocess. Mix at least 2 nonequivalent atomic orbitals (e.g. sand p).Hybrid orbitals have very different shapefrom original atomic orbitals.
Slide 5 : SHAPE OF ATOMIC ORBITALS
Slide 6 : Hybridization is a major player in this approach to bonding.
There are two ways orbitals can overlap to form bonds between atoms. Sigma () Bonds –Formed by s-s ,s-p and axial overlap of p-p orbitals Sigma bonds are characterized by Head-to-head overlap.
Cylindrical symmetry of electron density about the internuclear axis. s BOND s BOND s BOND
Slide 7 : Pi () Bonds Pi ( bonds are characterized by
Side-to-side or lateral, or unsymmetrical overlap of atomic orbitals
Electron density above and below the internuclear axis. )
Slide 8 : BOND FORMATION Overlapping of atomic orbitals s and p bond formation
Slide 9 : BONDING IN METHANE Sp3 HYBRIDIZATION ground state excited state hybridized state CARBON The formation of four sp3 hybrid orbitals by combination of an atomic s orbital with three atomic p orbitals. Each sp3 hybrid orbital has two lobes, one of which is larger than the other. The four large lobes are oriented toward the corners of a tetrahedron at angles of 109.5°. The carbon atom is sp3 hybridized to obtain tetrahedral geometry
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Slide 11 : 11 4 sp3 orbitals s + 3 p
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Slide 13 : The bonding in methane. Each of the four C-H bonds results from head-on (s) overlap of a singly occupied carbon sp3 hybrid orbital with a singly occupied hydrogen 1s orbital. Sigma bonds are formed by head-to-head overlap between the hydrogen s orbital and a singly occupied sp3 hybrid orbital of carbon. BONDING IN METHANE
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