Acid-Base Chemistryy
Sept 16
Chapter 6:177, 180-183
HW: 1, 2, 3, 4, 5, 6, 8ac, 9, 10b, 11, 12
Goals: Contrast Lewis acid/base with
B
Bronsted;
t d Use
U frontier
f
ti orbitals
bit l to
t construct
t
t
dative bonds
2 ... - 6 6 6UMass
6 6 Amherst
Created by Karsten Theis
Frontier Orbitals are the key (HOMO and LUMO)
- 6 6 6 6 6 2 ... 2
Which statement(s) are true?
1. A Lewis base donates electrons from its LUMO
2 A Lewis acid donates electrons from its LUMO
2.
3. A Lewis base donates electrons from its HOMO
4. A Lewis acid accepts electrons into its LUMO
A) 1, 4 are usually true
B) 1, 4 are always true
C) 3, 4 are always true
D) 3, 4 are usually true
E) 2, 4 are always true
- 6 6 6 6 6 2 ... 3
ƒ BF3OEt2 is used as a Lewis acid catalyst. Explain
how it works
- 6 6 6 6 6 2 ... 4
Molecular Orbitals for dative bonds
Which letter corresponds to the
antibonding LUMO of the
Lewis acid?
Can you explain the phases in
the resultant MOs?
- 6 6 6 6 6 2 ... 5
Which two adducts will form stable dative
bonds with H2O?
Which two adducts
will form stable
dative bonds
with H2O?
A)
B)
C)
D)
E)
- 6 6 6 6 6 2 ... 6
Examples of Coordinate bonds (AKA dative) (AKA
Lewis acid/base adducts)
- 6 6 6 6 6 2 ... 7
Example of CO as a Lewis Base (REALLY!)
- 6 6 6 6 6 2 ... 8