Transcript Hybridisation

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/nonbonded 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/nonbonded 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 OH bonds slightly closer together forming a
bond angle of 105 º
sp3 hybridisation in water
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
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
sp2
From: http://www.neiu.edu/~ncaftori/eng/propene.GIF
sp3
sp2