Unit 6: Symmetry in Molecular Structures In order to better understand the spectroscopy portion of this course (Units 7–9), you need to learn about molecular symmetry and some point group theory. Symmetrical molecules behave very differently with respect to unsymmetrical ones when it comes to interaction with light.
Unit 6 Time Advisory
This unit will take you 9 hours to complete.
☐ Subunit 6.1: 4 hours
☐ Subunit 6.2: 3 hours
☐ Subunit 6.3: 2 hours
Unit6 Learning Outcomes
Upon successful completion of this unit, the student will be able to:
- List and explain the symmetry elements.
- Apply the symmetry to wavefunctions.
- Compute mathematical operations involving symmetry elements and wavefunctions.
- Identify the symmetry in molecular structures.
- Assign symmetry labels using character tables.
6.1 Symmetry and Group Theory
- Reading: University of California-Davis: UC Davis ChemWiki’s
“Group Theory”
Link: University of California-Davis: UC Davis ChemWiki’s “Group
Theory”
(HTML)
Instructions: Click on the link above to the UC Davis ChemWiki, and read the entire webpage to learn about group theory. Pay close attention to the symmetry elements of each molecule and how they are used to derive the point group. Studying this resource should take approximately 4 hours to complete.
Terms of Use: Please respect the copyright and terms of use displayed on the webpage above.
6.2 Symmetry in Molecular Structures
- Reading: Reading: University of California-Davis: UC Davis
ChemWiki’s “Group Theory and its Application to Chemistry”
Link: University of California-Davis: UC Davis ChemWiki’s “Group
Theory and its Application to
Chemistry”
(HTML)
Instructions: Click on the link above to the UC Davis ChemWiki, and read the entire webpage to learn about the chemical applications of group theory. Studying this resource should take approximately 3 hours to complete.
Terms of Use: Please respect the copyright and terms of use displayed on the webpage above.
6.3 Character Tables and Symmetry Labels
-
Reading: University of California-Davis: UC Davis ChemWiki’s “Character Table” and “Understanding Character Tables of Symmetry Groups” Links: University of California-Davis: UC Davis ChemWiki’s “Character Table” and “Understanding Character Tables of Symmetry Groups” (HTML)
Instructions: Click on the links above and read through the entire webpages to learn about character tables and their applications to spectroscopy. Studying these resources should take approximately 2 hours to complete.
Terms of Use: Please respect the copyright and terms of use displayed on the webpage above. -
Assessment: The Saylor Foundation’s “Assessment 10” Link: The Saylor Foundation’s “Assessment 10” (DOC)
Instructions: Complete the attached assessment questions to check your understanding of the material covered thus far. Once you have completed the assessment, you may check your answers against the “Answer Key” (DOC).
Completing this assessment should take approximately 1 hour.