hybridization 1
DESCRIPTION
jjbTRANSCRIPT
7/18/2019 Hybridization 1
http://slidepdf.com/reader/full/hybridization-1 1/37
Copyright©2000 by HoughtonMifflin Company. All rights reserved.
1
Covalent Bonding: OrbitalsChapter 09
7/18/2019 Hybridization 1
http://slidepdf.com/reader/full/hybridization-1 2/37
Copyright©2000 by HoughtonMifflin Company. All rights reserved.
2
The four bonds around C are of equal length and Energy
7/18/2019 Hybridization 1
http://slidepdf.com/reader/full/hybridization-1 3/37
Copyright©2000 by HoughtonMifflin Company. All rights reserved.
3
Can you explain this based on your knowledge
of electron energy levels?
6C
1s2 2s2 2p2
Bonding from s is
Different from bondingFrom p. In addition the
Angles should be within
900!
7/18/2019 Hybridization 1
http://slidepdf.com/reader/full/hybridization-1 4/37
Copyright©2000 by HoughtonMifflin Company. All rights reserved.
4
How to generate four equal orbitals?
7/18/2019 Hybridization 1
http://slidepdf.com/reader/full/hybridization-1 5/37
Copyright©2000 by HoughtonMifflin Company. All rights reserved.
5
Hint:
A key to wave mechanics is
superposition
Which is creating new waves from interference of old ones
7/18/2019 Hybridization 1
http://slidepdf.com/reader/full/hybridization-1 6/37
Copyright©2000 by HoughtonMifflin Company. All rights reserved.
6
An energy-level diagram showing the
formation of four sp
3
orbitals.
7/18/2019 Hybridization 1
http://slidepdf.com/reader/full/hybridization-1 7/37
Copyright©2000 by HoughtonMifflin Company. All rights reserved.
7
Hybridize at n=2 sp3 sp3 sp3 sp3
s px py pz
s px py pz
Hybridization
sp3 sp3 sp3 sp3
Four sp3 orbitals of equal length, energy and in tetrahedral shape
Ground state of C 1s2 2s2 sp2
Promote electron at n=2 2s1
2p3
7/18/2019 Hybridization 1
http://slidepdf.com/reader/full/hybridization-1 8/37
Copyright©2000 by HoughtonMifflin Company. All rights reserved.
8
Hybridization
The mixing of atomic orbitals to formspecial orbitals for bonding.
The atoms are responding as needed to givethe minimum energy for the molecule.
7/18/2019 Hybridization 1
http://slidepdf.com/reader/full/hybridization-1 9/37
Copyright©2000 by HoughtonMifflin Company. All rights reserved.
9
Valence Bond Theory and NH3
N – 1s22s22p3
3 H – 1s1
If use the
three 2p orbitals
predict 900
Actual H-N-H bond angle is 107.30
How do you explain this?
2s 2px 2py 2pz
7/18/2019 Hybridization 1
http://slidepdf.com/reader/full/hybridization-1 10/37
Copyright©2000 by HoughtonMifflin Company. All rights reserved.
10
2s 2px 2py 2pzOriginal
Mix 1s and 3pAnd generate four
Equivalent sp3
Hybridized orbitals
sp3 sp3 sp3 sp3
3 bonding orbitals
Which can accommodate
The 1s1 electron from
hydrogen
1 sp3
lone
pair
Consider the n=2 for N
7/18/2019 Hybridization 1
http://slidepdf.com/reader/full/hybridization-1 11/37
Copyright©2000 by HoughtonMifflin Company. All rights reserved.
11
The nitrogen atom in ammonia is sp3
hybridized.
7/18/2019 Hybridization 1
http://slidepdf.com/reader/full/hybridization-1 12/37
Copyright©2000 by HoughtonMifflin Company. All rights reserved.
12
7/18/2019 Hybridization 1
http://slidepdf.com/reader/full/hybridization-1 13/37
Copyright©2000 by HoughtonMifflin Company. All rights reserved.
13
An orbital energy-level diagram for sp2
hybridization. Note that one p orbital
remains unchanged.
7/18/2019 Hybridization 1
http://slidepdf.com/reader/full/hybridization-1 14/37
Copyright©2000 by HoughtonMifflin Company. All rights reserved.
14
7/18/2019 Hybridization 1
http://slidepdf.com/reader/full/hybridization-1 15/37
Copyright©2000 by HoughtonMifflin Company. All rights reserved.
15
When an s and two p orbitals are mixed to form a set
of three sp2 orbitals, one p orbital remains unchanged
and is perpendicular to the plane of the hybrid orbitals.
7/18/2019 Hybridization 1
http://slidepdf.com/reader/full/hybridization-1 16/37
Copyright©2000 by HoughtonMifflin Company. All rights reserved.
16
7/18/2019 Hybridization 1
http://slidepdf.com/reader/full/hybridization-1 17/37
Copyright©2000 by HoughtonMifflin Company. All rights reserved.
17
Figure 9.13: (a) The orbitals used to form
the bonds in ethylene. (b) The Lewis
structure for ethylene.
7/18/2019 Hybridization 1
http://slidepdf.com/reader/full/hybridization-1 18/37
Copyright©2000 by HoughtonMifflin Company. All rights reserved.
18
7/18/2019 Hybridization 1
http://slidepdf.com/reader/full/hybridization-1 19/37
Copyright©2000 by HoughtonMifflin Company. All rights reserved.
19 Sigma bond (s) –
electron density between the 2 atomsPi bond (p) – electron density above and below plane of nuclei
of the bonding atoms
7/18/2019 Hybridization 1
http://slidepdf.com/reader/full/hybridization-1 20/37
Copyright©2000 by HoughtonMifflin Company. All rights reserved.
20
The s bonds in ethylene. Note that for each bond the
shared electron pair occupies the region directly between
the atoms.
7/18/2019 Hybridization 1
http://slidepdf.com/reader/full/hybridization-1 21/37
Copyright©2000 by HoughtonMifflin Company. All rights reserved.
21
A sigma (s
) bond centers along theinternuclear axis.
A pi (p) bond occupies the space above and
below the internuclear axis.
CC
H H
HH
s
p
7/18/2019 Hybridization 1
http://slidepdf.com/reader/full/hybridization-1 22/37
Copyright©2000 by HoughtonMifflin Company. All rights reserved.
22
(a)The orbitals used
to form the bondsin ethylene.
(b) The Lewis
structure forethylene.
7/18/2019 Hybridization 1
http://slidepdf.com/reader/full/hybridization-1 23/37
Copyright©2000 by HoughtonMifflin Company. All rights reserved.
23
The orbital energy-level diagram for the
formation of sp hybrid orbitals on carbon.
7/18/2019 Hybridization 1
http://slidepdf.com/reader/full/hybridization-1 24/37
Copyright©2000 by HoughtonMifflin Company. All rights reserved.
24
7/18/2019 Hybridization 1
http://slidepdf.com/reader/full/hybridization-1 25/37
Copyright©2000 by HoughtonMifflin Company. All rights reserved.
25
When one s orbital and one p orbital are
hybridized, a set of two sp orbitals oriented at
180 degrees results.
7/18/2019 Hybridization 1
http://slidepdf.com/reader/full/hybridization-1 26/37
Copyright©2000 by HoughtonMifflin Company. All rights reserved.
26
The orbitals of an sp hybridized
carbon atom.
7/18/2019 Hybridization 1
http://slidepdf.com/reader/full/hybridization-1 27/37
Copyright©2000 by HoughtonMifflin Company. All rights reserved.
27
7/18/2019 Hybridization 1
http://slidepdf.com/reader/full/hybridization-1 28/37
Copyright©2000 by HoughtonMifflin Company. All rights reserved.
28
The orbital arrangement for an sp2hybridized
oxygen atom to form CO2.
8O 1s22s22p4
7/18/2019 Hybridization 1
http://slidepdf.com/reader/full/hybridization-1 29/37
Copyright©2000 by HoughtonMifflin Company. All rights reserved.29
The hybrid orbitals in the CO2 molecule.
7/18/2019 Hybridization 1
http://slidepdf.com/reader/full/hybridization-1 30/37
Copyright©2000 by HoughtonMifflin Company. All rights reserved.30
(a) The orbitals used to form the bonds in carbon dioxide. Note
that the carbon-oxygen double bonds each consist of one s bond
and one p bond. (b) The Lewis structure for carbon dioxide.
2sp orbitals from C to form two double bonds
( ) A h b idi d i (b) h b d i h
7/18/2019 Hybridization 1
http://slidepdf.com/reader/full/hybridization-1 31/37
Copyright©2000 by HoughtonMifflin Company. All rights reserved. 31
(a) An sp hybridized nitrogen atom. (b) The s bond in the N2
molecule. (c) The two p bonds in N2 are formed when electron
pairs are shared between two sets of parallel p orbitals. (d) The
total bonding picture for N2.
7/18/2019 Hybridization 1
http://slidepdf.com/reader/full/hybridization-1 32/37
Copyright©2000 by HoughtonMifflin Company. All rights reserved. 32
Sigma (s) and Pi Bonds (p)
Single bond1 sigma bond
Double bond 1 sigma bond and 1 pi bond
Triple bond 1 sigma bond and 2 pi bonds
How many s and p bonds are in the acetic acid
(vinegar) molecule CH3COOH?
C
H
H
CH
O
O Hs bonds = 6 + 1 = 7
p bonds = 1
10.5
7/18/2019 Hybridization 1
http://slidepdf.com/reader/full/hybridization-1 33/37
Copyright©2000 by HoughtonMifflin Company. All rights reserved. 33
How to generate more than 4
bonds?
Remember the PCl5, SF6, etc…
The s and 3p can generate 4 orbitals
Include d orbitals to generate more!
7/18/2019 Hybridization 1
http://slidepdf.com/reader/full/hybridization-1 34/37
Copyright©2000 by HoughtonMifflin Company. All rights reserved. 34
s p p p d d d d d
Hybridize 1s and 3p and 1d
Result in 5 dsp3 orbitals
dsp3 dsp3 dsp3 dsp3 dsp3
1 2 3 4 5
A f d 3 h b id bi l h h
7/18/2019 Hybridization 1
http://slidepdf.com/reader/full/hybridization-1 35/37
Copyright©2000 by HoughtonMifflin Company. All rights reserved. 35
A set of dsp3 hybrid orbitals on a phosphorus atom.
Note that the set of five dsp3 orbitals has a trigonal
bipyramidal arrangement. (Each dsp3 orbital also has a
small lobe that is not shown in this diagram.)
(a) The PCl5 molecule (b) The orbitals used to form the bonds in
7/18/2019 Hybridization 1
http://slidepdf.com/reader/full/hybridization-1 36/37
Copyright©2000 by HoughtonMifflin Company. All rights reserved. 36
(a) The PCl5 molecule. (b) The orbitals used to form the bonds in
PCl5. The phosphorus uses a set of five dsp3 orbitals to share
electron pairs with sp3 orbitals on the five chlorine atoms. The
other sp3 orbitals on each chlorine atom hold lone pairs.
f 6 bi l ?