HL Bonding

Hybridisation

• Hybridization is a model which is used to explain the behavior of atomic orbitals during the formation of covalent bonds.

• When an atom forms a covalent bond with another atom, the orbitals of the atom become rearranged.

• This rearrangement results in the "mixing" of orbitals.

From: http://www.bookrags.com/Orbital_hybridisation

Hybridisation

• When atoms join together to form molecules, their atomic orbitals interact with each other to form hybrid orbitals

Hybridisation

• When atoms join together to form molecules, their atomic orbitals interact with each other to form hybrid orbitals

• This process is called hybridisation

Hybridisation

• When atoms join together to form molecules, their atomic orbitals interact with each other to form hybrid orbitals

• This process is called hybridisation• The orbitals formed in this process are of the

same energy

Hybridisation

• When atoms join together to form molecules, their atomic orbitals interact with each other to form hybrid orbitals

• This process is called hybridisation• The orbitals formed in this process are of the

same energy• The orbitals are symmetrically arranged

Hybridisation

• When atoms join together to form molecules, their atomic orbitals interact with each other to form hybrid orbitals

• This process is called hybridisation• The orbitals formed in this process are of the

same energy• The orbitals are symmetrically arranged• 3 types - sp3, sp2 and sp

Hybridisation

• When atoms join together to form molecules, their atomic orbitals interact with each other to form hybrid orbitals

• This process is called hybridisation• The orbitals formed in this process are of the

same energy• The orbitals are symmetrically arranged• 3 types - sp3, sp2 and sp• Hybridisation doesn’t just occur in carbon

sp3 hybridisation

• E.g. methane, ammonia, water

sp3 hybridisation

• E.g. methane, ammonia, water

• Methane contains 4 equal C - H bonds, therefore the outer shell electrons (2s2 2p2) have merged to form 4 hybrid sp3 orbitals of equal energy

sp3 hybridisation

• E.g. methane, ammonia, water

• Methane contains 4 equal C - H bonds, therefore the outer shell electrons (2s2 2p2) have merged to form 4 hybrid sp3 orbitals of equal energy

• One electron is in each of the hybrid orbitals and can form a sigma bond with a hydrogen atom

sp3 hybridisation in methane

From http://ibchem.com/IB/ibnotes/full/bon_htm/14.2.htm

sp3 hybridisation

• The four hybrid orbitals arrange themselves to be as far apart as possible because of the repulsion between the electrons

• This produces the tetrahedral shape of methane and a bond angle of 109.5º

sp3 hybridisation in methane

From http://www.mhhe.com/physsci/chemistry/carey5e/Ch02/ch4hybrid2.gif

sp3 hybridisation in water

• A similar thing occurs in water - 4 sp3 hybridised orbitals are formed around the oxygen and spread out in a tetrahedral shape

sp3 hybridisation in water• A similar thing occurs in water - 4 sp3

hybridised orbitals are formed around the oxygen and spread out in a tetrahedral shape

• Two of these orbitals contain lone/non-bonded pairs of electrons, and the other two form sigma bonds with the hydrogen atoms

sp3 hybridisation in water• A similar thing occurs in water - 4 sp3

hybridised orbitals are formed around the oxygen and spread out in a tetrahedral shape

• Two of these orbitals contain lone/non-bonded pairs of electrons, and the other two form sigma bonds with the hydrogen atoms

• As the non-bonded pairs are closer to the centre of the molecule, they force the two O-H bonds slightly closer together forming a bond angle of 105 º

From: http://www.rjc.edu.sg/subjects/chemistry/resources/simulations-hybridisation/lecture28.html

sp3 hybridisation in water

From: http://www.rjc.edu.sg/subjects/chemistry/resources/simulations-hybridisation/lecture28.html

sp3 hybridisation in water

sp2 hybridisation

• E.g. ethene - C2H4, BF3

sp2 hybridisation

• E.g. ethene - C2H4, BF3

• In ethene, one 2p orbital from each carbon atom forms a pi bond - this is not involved in hybridisation

sp2 hybridisation

• E.g. ethene - C2H4, BF3

• In ethene, one 2p orbital from each carbon atom forms a pi bond - this is not involved in hybridisation

• The remaining 2s orbital and two 2p orbitals hybridise to form three sp2 orbitals, which form sigma bonds - two with hydrogen atoms and one between the C atoms

sp2 hybridisation in ethene

From: http://www.rsu.ac.th/science/chem/yupa/Arjarnyupa/1historyorganic/sp2.htm

Hybridisation in BF3

From: http://www.rjc.edu.sg/subjects/chemistry/resources/simulations-hybridisation/lecture28.html

sp hybridisation

• E.g. ethyne (C2H2), BeF2

sp hybridisation• E.g. ethyne (C2H2), BeF2

• The 2s orbital hybridises with just one of the 2 p orbitals

sp hybridisation• E.g. ethyne (C2H2), BeF2

• The 2s orbital hybridises with just one of the 2 p orbitals

• In BeF2 this is because there are only 2 electrons in the 2nd shell (1s2 2s2)

sp hybridisation• E.g. ethyne (C2H2), BeF2

• The 2s orbital hybridises with just one of the 2 p orbitals

• In BeF2 this is because there are only 2 electrons in the 2nd shell (1s2 2s2)

• In ethyne this is because two pi bonds are formed between the carbons leaving only 2 electrons on each carbon to form sigma bonds - one with a H atom and one with the other C atom

sp hybridisation in ethyne

From: http://www.citycollegiate.com/hybridization2.htm

sp hybridisation in BeF2

From: http://www.rjc.edu.sg/subjects/chemistry/resources/simulations-hybridisation/lecture28.html

Question

• Identify the type of hybridisation in each of the carbon atoms in propene

From: http://www.neiu.edu/~ncaftori/eng/propene.GIF

Answer• Identify the type of hybridisation in each of the carbon atoms in propene

From: http://www.neiu.edu/~ncaftori/eng/propene.GIF

sp3

sp2

sp2