First Semester Inorganic Chemistry / Foundation Course in Inorganic Chemistry

27 Jun 2019

Porphyrin-Based Metal-Organic Frameworks

Submitted by Amanda Bowman, Colorado College
Evaluation Methods: 

Students completed this activity in small groups, then turned in individual worksheets. Student learning and performance were assessed through 1) in-class group discussion after they had worked on the activity in small groups, and 2) grading the individual worksheets. Participation was most important in the small-group portion.

Evaluation Results: 

In general, students really enjoyed this exercise and felt that it was helpful for visualizing metal-organic frameworks (particularly the extended 3D structure). They also generally felt that it was helpful in visualizing the bonding sites of metal vertices, particularly for thinking about how that influences potential reactivity. We used Mercury as a visualization software for this discussion, and the majority of students felt very comfortable using Mercury and looking at cifs on their own after this activity.

 

The biggest challenge for students seemed to be in relating the 3D structure in the cif to the images and chemicals formulas in the article. They also tended to need some hints about question 5 – to think about what information Mössbauer can provide about oxidation state of the metal, or that you can tell whether or not there are two distinct iron environments. In our class, we do brief units on X-ray crystallography including how to use and interpret cifs, and Mössbauer spectroscopy before this literature discussion. If those topics are not already addressed in a particular class it might be helpful to add them in or directly address those topics for the students as an introduction to the literature discussion.

Description: 

This literature discussion explores the physical structures, electronic structures, and spectroscopic characterization of several porphyrin-based metal-organic frameworks through discussion of “Iron and Porphyrin Metal−Organic Frameworks: Insight into Structural Diversity, Stability, and Porosity,” Fateeva et al. Cryst. Growth Des. 2015, 15, 1819-1826, http://dx.doi.org/doi:10.1021/cg501855k. The activity gives students experience visualizing and interpreting MOF structures, and gives students exposure to some of the methods used to characterize MOFs.

Corequisites: 
Course Level: 
Learning Goals: 

Students will be able to:

  • Interpret and describe the bonding and structural characteristics of MOFs
  • Apply knowledge of ligand field strength to electronic structure of MOFs
  • Analyze X-ray crystallographic data to gain information about structural characteristics of MOFs
  • Interpret Mössbauer spectra to gain information about electronic structure of MOFs
Implementation Notes: 

This literature discussion was designed for use in an advanced (upper-level) inorganic chemistry course, but could be used in a foundational inorganic course if students have already been introduced to d-splitting diagrams and are given some coverage of Mössbauer spectroscopy and X-ray crystallography. When covering MOFs in class, students frequently expressed that visualizing and understanding the bonding sites and extended 3D structures was very challenging. So, this literature discussion was developed specifically to address that. Students completed this activity in small groups. It is very helpful to advise students ahead of time to bring laptops (or instructor should have some available) and to have the cifs from the paper downloaded and ready to go. We used Mercury as a visualization software for this activity. This activity can easily be completed in one class period. It is also helpful if students have been provided with the article ahead of time and encouraged to look it over – otherwise the most time-consuming part of this activity was allowing time for students to examine the MOF structure images in the paper before being able to discuss and answer the questions with their groups.

Note on visualization of MOFs using Mercury: To answer the discussion questions, we used the ‘stick’ or the ‘ball and stick’ style. We also used the default packing scheme (0.4x0.4x0.4) and the 1x1x1 packing scheme. The packing scheme can be changed by selecting Packing/Slicing… in the Calculate menu. I also had students view the 3x3x3 packing scheme – while this is not necessary to answer the discussion questions, it was interesting for students to be able to visualize the extended structure of the MOFs.

 

9 Jun 2019

Chem 165 2018

Submitted by Adam R. Johnson, Harvey Mudd College

This is a collection of LOs that I used to teach a junior-senior seminar course on organometallics during Fall 2018 at Harvey Mudd College. There were a total of 9 students in the course. The Junior student (there was only one this year) was taking 2nd semester organic concurrently and had not takein inorganic (as is typical).

Subdiscipline: 
Corequisites: 
Course Level: 
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.

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
Description: 

This Literature Discussion is based on the article “Square-planar Co(III) {O4} coordination: large ZFS and reactivity with ROS” by Linda Doerrer et. al.   It includes a reading guide that will direct students to specific sections of the paper that highlight some of the key results and analytical techniques that lead to them.

Corequisites: 
Course Level: 
Learning Goals: 
  1. Interpret results in high-level scientific papers, which will help them gain confidence in their abilities to read papers.

  2. Identify conclusions from the text of a paper, given an indicated scheme and data set.

  3. Synthesize multiple conclusions from different sections of a paper into an overall understanding of the conclusions of a paper

  4. Relate oxidation state to bond lengths in real examples

  5. Compare low- and high-spin d-orbital splitting diagrams.

  6. Identify unpaired electrons in a splitting diagram.

  7. Relate electron-density to acidity and ligand field strength.

  8. Recognize that science is collaborative and involves experts in many fields.

Implementation Notes: 

These questions are drawn from key conclusions in the text of the paper. It could be useful to highlight the specific areas of the text, or to include a statement like the following:

 

"For the following questions, specific figures and acronyms are mentioned. Often, authors will include a reference to a specific figure in the text when they are drawing conclusions from the data, and so it can be useful to find those specific sentences in the text of the paper when you are analyzing their data and conclusions."

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
6 May 2019
Evaluation Methods: 
  • The instuctor walked around the classroom to help students individually as needed for immediate assessment.
  • At the end of the class period, students submitted their work to Blackboard for grading.
  • Assignments were graded based on accuracy and quality of the drawings.
Evaluation Results: 

Students generally were able to determine the molecular formula and generate connectivity drawings of the displayed 3-D structures, but really struggled with 3-D drawing. Although this was developed for a course with second year students who had completed general chemistry, even older students in the course struggled with this component. However, by the end of class, all students greatly improved in their ability to understand, interpret, and convey 3-D structure. 

Many students were surprised and many jokes were made about this being a chemistry art class. Although some students didn't particularly enjoy drawing, all understood the value and felt like they had learned something useful. At the end of the semester, many students remarked that the chemical drawing section was the most useful or interesting. 

Description: 

This in-class activity was designed for a Chemical Communications course with second-year students. It is the first part of a two-week segment in which students learn how to use Chemdraw (or similar drawing software) to create digital drawings of molecules.

In this activity, students are given a blank worksheet and 5 models of molecules were placed around the classroom. Students interpreted the 3-D models to determine molecular formulas, connectivity, and generate drawings that convey the 3-D elements. Once students completed the worksheet by hand, they generated the whole worksheet using Chemdraw.

Learning Goals: 

Students will be able to:

1.    Write the formula for a molecule based on a 3-D structure.

2.    Draw a molecule based on a 3-D structure.

3.    Convey 3-D structure of a molecule in a drawing.

4.    Translate molecular connectivity to a drawing that conveys 3 dimensions.

5.    Create digital drawings of molecules using Chemdraw or similar chemical drawing software.

Equipment needs: 
  • Molecular model set for the instructor to prepare structures before class.
  • One computer per student with chemical drawing software such as Chemdraw.
Course Level: 
Implementation Notes: 

Prior to the activity, students were given a brief presentation with an introduction to basic Chemdraw elements using the Chemdraw manual and existing tutorials (see links provided). VSEPR was also reviewed.

For the activity, students were given 3-D models of molecules, and the color key for atom identity was written on the board (eg. blue = oxygen, black = carbon...). The activity was conducted in a class of 24 students, in which each student had access to a computer. The entire class period was 1 hour 50 min, but the activity could be shortened if fewer molecules are included.

Before class, the instructor built models of molecules using a molecular model kit. It is helpful to have multiple copies of each molecule, especially for a larger class, but not critical. The molecules used for the acitvity can be seen in the faculty-only key, and were chosen to have a range of 3-D structures, but other molecules could be chosen. For example, a coordination chemistry or upper division course could have 3-D printed models of crystal structures used as the starting point. 

Time Required: 
60 min
26 Mar 2019

Redox-switch polymerization catalysis

Submitted by Chip Nataro, Lafayette College
Evaluation Methods: 

I am really unsure at this point. I may use the 1FLO version of this as a series of exam quesitons, or I may have the students work on this literature discussion in class. Either way, I am excited to see what they will do with it.

Description: 

This is the full literature discussion based on a communicaiton (J. Am. Chem. Soc. 2011133, 9278). This paper describes a redox-switch yttrium catalyst that is an active catalyst for the polymerization of L-lactide in the reduced form and inactive in the oxidized form. The catalyst contains a ferrocene-based ligand that serves as the redox active site in the catalyst. This full literature discussion is an extension of the one figure literature discussion that is listed below. In addition to presenting all of the same questions as that learning object, this includes interpretation of the XANES spectra presented in the paper. It also asks the students to identify the monomer and polymer in the reaction of interest. A possible extension of this learning object would be to have students examine and take measurements from the crystal structure presented in the paper in order to support the apparently low electron count on the yttrium catalyst. The Covalent Bond Classification system for counting electrons is used in this learning object.

Corequisites: 
Course Level: 
Learning Goals: 

A student should be able to apply their knowledge to 

  1. describe and interpret a plot of conversion vs. time
  2. count electrons and determine valence states in organometallic compounds
  3. determine if an organometallic compound is an oxidizing or reducing agent
  4. decipher a first-order kinetic plot
  5. interpret XANES spectra to determine the valence of iron in the catalyst
Subdiscipline: 

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