Molecular Structure and Bonding

25 Jul 2019

1FLO: One Figure Learning Objects

Submitted by Chip Nataro, Lafayette College
Corequisites: 
9 Jun 2019

An improved method for drawing the bonding MO for dihydrogen

Submitted by Adam R. Johnson, Harvey Mudd College
Evaluation Methods: 

When I do this correctly, the students don't accidentally see something which may make immature students giggle.

Evaluation Results: 

I have had multiple colleagues tell me that this technique worked for them and saved them from repeating an embarassing classroom event.

Description: 
Most of us have probably been there. Discussing homonuclear diatomic MO diagrams and on the first day you want to put up the sigma bonding molecular orbital for H2. If you teach it like me, you emphasize the LCAO-MO approach, so you draw a hydrogen atom with its 1s orbital interacting with a hydrogen atom with its 1s orbital...and then you notice giggling from the less mature audience members. My technique will help to prevent this from happening. The technique is in the "faculty only" files section.
Learning Goals: 

The instructor will draw the bonding MO of dihydrogen without accidentally causing laughter in the class or self embarassment.

Corequisites: 
Equipment needs: 

chalkboard or whiteboard

ability to adjust quickly just in case

Prerequisites: 
Implementation Notes: 

I have come close to accidentally drawing the incorrect version of this diagram and I am able to stop myself quickly as illustrated in the instructions. 

Time Required: 
a minute to learn, a lifetime to master.
8 Jun 2019

VIPEr Fellows 2019 Workshop Favorites

Submitted by Barbara Reisner, James Madison University

During our first fellows workshop, the first cohort of VIPEr fellows pulled together learning objects that they've used and liked or want to try the next time they teach their inorganic courses.

7 Jun 2019

Guideline for drawing chemical structures

Submitted by Bradley Wile, Ohio Northern University
Description: 

This is the set of guidelines provided for authors by Nature Research. A 6-page PDF gives explicit guidance about rendering molecules using chemical drawing software, and a downloable ChemDraw template (.cds) is provided.

Prerequisites: 
Corequisites: 
Related activities: 
Implementation Notes: 

I give this to all of my research students as part of the welcome to the group package.

6 Jun 2019

VSEPR: Flash Review

Submitted by Christopher Durr, Amherst College
Description: 

This presentation is meant to be a review of applying VSEPRup to steric number 6. It's designed to be viewed as a powerpoint and printed out to keep for the student's notebook.

It can be used at multiple levels: as a review immediately after learning VSEPR in general chemistry, or as a refresher before starting upper level inorganic chemistry. The instructor could add text or voice over the slides to add more detail or leave the presentation as is for students.

If you'd like .psd or .pdf files of the drawings in these presentation, please contact me directly.

Prerequisites: 
Corequisites: 
Learning Goals: 

After reviewing this material students should be able to:

Draw the correct VSEPR predicted structure of a molecule based on steric number and lone pair count.

Name VSEPR structures with their appropriate geometry.

Avoid common VSEPR mistakes, particularly those with steric number 5 and 6.

Recognize how lone pairs distort bond angles from ideal geometry in molecules like ClF3

 

Implementation Notes: 

I plan on uploading this flash review (along with others) to my class site before students arrive to my upper level inorganic course. I will voice over the slides, explaining the concepts, so they're ready to apply molecular orbital theory on the first day of class.

Time Required: 
10 - 15 Minutes
Evaluation
Evaluation Methods: 

I will compare student preparedness between this class and a previous one that did not receive a review.

Evaluation Results: 

This will be updated in the future.

6 Jun 2019

Molecular Orbital Theory: Flash Review

Submitted by Christopher Durr, Amherst College
Description: 

This presentation is meant to be a review of constructing and utilizing an MO diagram, in this case O2. It's designed to be viewed as a powerpoint and printed out to keep for the student's notebook.

It can be used at multiple levels: as a review immediately after learning MO theory in general chemistry, or as a refresher before starting upper level inorganic chemistry. The instructure could add text or voice over the slides to add more detail or leave the presentation as is for students.

If you'd like .psd or .pdf files of the drawings in these presentation, please contact me directly.

 

 

Prerequisites: 
Corequisites: 
Learning Goals: 

After reviewing this material students should be able to:

Recall the shape, size and appropriate nodes of atomic orbitals.

Note the appropriate electron configuration of a given atom.

Draw molecular orbitals with the appropriate sign and node position.

Apply the Aufbau Principle to molecular orbitals to determine the ultimate spin state of a molecule.

Determine the bond order of a molecule from a completed MO diagram.

Manipulate the bond order of a molecule with Reduction/Oxidation.

 

Implementation Notes: 

I plan on uploading this flash review (along with others) to my class site before students arrive to my upper level inorganic course. I will voice over the slides, explaining the concepts, so they're ready to apply molecular orbital theory on the first day of class.

Time Required: 
10 - 15 Minutes
Evaluation
Evaluation Methods: 

I will compare student preparedness between this class and a previous one that did not receive a review.

Evaluation Results: 

This will be updated in the future.

6 Jun 2019
Evaluation Methods: 

The guided reading questions may be graded using the answer key. 

Evaluation Results: 

These questions have not yet been assigned to students.

Description: 

Guided reading and in-class discussion questions for "High-Spin Square-Planar Co(II) and Fe(II) Complexes and Reasons for Their Electronic Structure."

Course Level: 
Learning Goals: 

1.  Bring together ligand field theory and symmetry.

  1. Students should be able to identify symmetry of novel molecules in the literature.

  2. Students should be able to explain d-orbital ordering in a coordination complex using ligand field theory.

  3. Students should be able to identify donor/acceptor properties of previously unseen ligands.

  4. Students should be able to apply your knowledge of electronic transitions to the primary literature.

  5. Students should be able to become more familiar with 4-coordinate geometries.

  6. Students should be able to predict magnetic moments of high-spin and low-spin square-planar complexes.

  7. Students should be able to identify properties of ligands that favor formation of the highly unusual high-spin square planar complexes.

2.  Students should comfortable with reading and understanding primary literature.


 

Related activities: 
Implementation Notes: 

You do not have to assign all of the guided reading questions at once.  You may consider assigning questions as they pertain to where you are in your inorganic chemistry class.

Time Required: 
this has not been used yet for in-class discussion.
6 Jun 2019
Evaluation Methods: 

The classroom discussion (participation, answers, etc) may be assessed by the instructor, or alternatively, these questions could be given to students to turn in.

Evaluation Results: 

None yet available.  Please leave yours in the comments!

Description: 

This literature discussion aims to have students in an advanced inorganic chemistry course interpret reaction schemes and electronic spectra, relate chemical formulae to molecular structure, and gain an understanding of how inorganic synthesis is planned and executed.  Students should gain an understanding of how counterions and crown ethers affect structure. Question 7 may be expanded to ask students to why pi-donor ability affects ligand field splitting, or as an introfuction to this topic.

An associated 1FLO based on this paper is linked in the related content.

 

Corequisites: 
Course Level: 
Learning Goals: 
Students will be able to:
  • Interpret reaction schemes and write balanced equations.
  • Rationalize the position of a ligand in the spectrochemical series based upon its π-donor/acceptor properties
  • Relate the electronic structure of tetrahedral d8 complexes to their magnetic properties
  • Analyze the impact of countercations on the geometry and electronic properties of the complexes.
Implementation Notes: 

This LO is intended for an advanced inorganic chemistry course.  Students should read the communication before class with questions above as guidance.  A classroom discussion should insue, in which students gain an insight into inorganic synthesis, and recognize how minor differences between compounds, such as counterions, have significant effects on electronic structure.

 

Time Required: 
50 minutes
6 Jun 2019

1FLO: Relating Electronic Spectra and Ligand Field Strength of [NiX4]2- Anions

Submitted by Wesley S. Farrell, United States Naval Academy
Evaluation Methods: 

Evaluate students' comprehension based on verbal in-class answers and ensuing discussion.

Evaluation Results: 

None yet available.

Description: 

This 1FLO asks students to interpret an electronic spectrum of 5 NiX42- anions.  Students will determine the relative ligand field strength, (re)familiarize themselves with terms such as "redshift" and "blueshift", and consider possible metal complex geometries.

Learning Goals: 
  1. Students (re)familiarize themselves with relationship between wavelength (λ) and wavenumber (cm-1).

  2. Students recall 4-coordinate geometries.

  3. Students define the terms “redshift” and “blueshift.”

  4. Students analyze data to construct a partial spectrochemical series.

Corequisites: 
Course Level: 
Equipment needs: 

None

Implementation Notes: 

This activity could be used as either a guided introduction to the spectrochemical series, or as an in-class activity to review after introduction.  If used as an introduction, question 4 may need modification.

Time Required: 
15 - 20 Minutes
5 Jun 2019

Zinc-Zinc Bonds (Expanded and Updated)

Submitted by Wesley S. Farrell, United States Naval Academy
Evaluation Methods: 

Performance and participation in the discussion will be assessed 

Evaluation Results: 

None collected yet. Evaluation data will be added in the future.

Description: 

This paper in Science reports the synthesis of decamethyldizincocene, a stable compound of Zn(I) with a zinc-zinc bond. In the original LO, the title compound and the starting material, bis(pentamethylcyclopentadienyl)zinc, offer a nice link to metallocene chemistry, electron counting, and different modes of binding of cyclopentadienyl rings as well as more advanced discussions of MO diagrams. More fundamental discussion could focus on the question of what constitutes the evidence for a chemical bond, in this case, the existence of a zinc-zinc bond. In this updated LO, these topics are still covered, however additional topics, such as point group idenitifaction, details regarding the reaction mechanism, electronic structure, and  searching the literature using SciFinder are covered.  Additionally, electron counting is divided into both the covalent and ionic models.

Corequisites: 
Course Level: 
Learning Goals: 
  1. Students should become more confident reading the primary literature

  2. Students should be able to apply existing knowledge to interpret research results.

  3. Students should be able to apply electron counting formalisms to organometallic compounds.

  4. Students should be able to use 1H NMR spectroscopy data to rationalize structure.

  5. Students can rationalize bond distances based on periodic trends in atomic radii

  6. Students use SciFinder to put this work into a larger context.

  7. Students identify redox reactions based on oxidation changes.

  8. Students identify molecular point groups based upon structures.

  9. Students should be able to connect d electron count to observed colors of compounds. 

Related activities: 
Implementation Notes: 

Students are asked to read the paper and the accompanying Perspectives article before class as well as answer the discussion questions. The questions serve as a useful starting point for class discussion. 

Time Required: 
50 minutes

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