Second year

10 May 2018

3D Sym Op

Submitted by Caroline Saouma, University of Utah
Evaluation Methods: 

None

Description: 

This is a great app that helps students see the symmetry in molecules. It allows you to choose a molecule (by name, structure, or point group) and display a 3D rendition of it. You can then have it display the symmetry elements, and/or apply all the symmetry operations. 

It is available for both android and apple phones: (probably easier to just search for it)

apple: https://itunes.apple.com/us/app/3d-sym-op/id1067556681?mt=8

android: https://play.google.com/store/apps/details?id=com.nus.symmo&hl=en_US

Topics Covered: 
Prerequisites: 
Learning Goals: 

A student should be able to find symmetry elements in molecules. 

Corequisites: 
Implementation Notes: 

In class I project my phone screen so they can see it, and I encourage the students to work along with their phones. I prefer this to models, as it is hard to remember what things looked like before you did the transformation, and moreover, my students have a hard time finding the symmetry elements. 

 

I encourage the students to play with it anytime they have a few spare moments- waiting for the bus, in line for food, etc. 

8 May 2018

Developing Effective Lab Report Abstracts based on Literature Examples

Submitted by Katherine Nicole Crowder, University of Mary Washington
Evaluation Methods: 

I use a rubric that I have developed (see attached).

They are graded out of 50 points: 5 points per category on the rubric.

Evaluation Results: 

Most students score between 40-49 on this assignment. They mostly lose points for grammar, including things that they shouldn't (which hits them in two categories - conciseness and only relevant information included), and forgetting to write a title.

Description: 

For inorganic lab, I have my students write their lab reports in the style of the journal Inorganic Chemistry. The first week of lab, we spend time in small groups looking at several examples of recent articles from Inorganic Chemistry, focusing mainly on the experimental section and the abstract (as these are included in every lab report). We then come back together as a class to have a discussion of each of the sections in the articles. We discuss what was included in each section, what wasn’t included, and the style, tone, tense, and voice of each section. I keep a running list of what we discuss to post on our CMS. It is a great opportunity to discuss the expectations for lab reports for this course (and they feel like they have a say in what they will be expected to include), and it is also a time to highlight what may be done slightly differently in inorganic versus some of the other sub-disciplines.

Following this discussion, I provide them with another current article from Inorganic Chemistry, except this time I have removed the abstract and all identifying information (authors, title, volume, page numbers, etc.) using editing (white boxes over the information) in pdf. Their assignment is to read through the article and then write their own title and abstract, keeping in mind the elements of our discussion as they write.

Since this is very early in the semester, I try to choose an interesting article that won’t be completely over their head. I also stress that they don’t have to completely understand the results to write about them, as they are usually summarized nicely in the conclusions section. Since I expect them to focus mainly on their results in their lab report abstracts, I try to choose articles that have a lot of numerical and spectral data to incorporate.

This year I chose

Systematic Doping of Cobalt into Layered Manganese Oxide Sheets Substantially Enhances Water Oxidation Catalysis

Ian G. McKendry, Akila C. Thenuwara, Samantha L. Shumlas, Haowei Peng, Yaroslav V. Aulin, Parameswara Rao Chinnam, Eric Borguet, Daniel R. Strongin, and Michael J. Zdilla

Inorganic Chemistry 2018 57 (2), 557-564

DOI: 10.1021/acs.inorgchem.7b01592

The students are evaluated based on their inclusion of the aspects of abstracts that we discussed, their summarization of the main findings of the article, and their grammar.

Corequisites: 
Prerequisites: 
Learning Goals: 

A student should be able to:

  • Identify common aspects of sections of literature article examples, namely the abstract and experimental section
  • Read a current literature article from Inorganic Chemistry and identify the main findings in order to write their own abstract for the article
  • Use these experiences to guide their writing for lab reports for the inorganic lab course
Equipment needs: 

None.

Implementation Notes: 

I bring 3-4 examples of articles that have abstracts that incorporate elements that I want them to include in their lab report abstracts. I bring 3-4 examples of articles that are mainly synthetic for their experimental sections, as that is what their labs will be mostly. I post these examples to our CMS after lab.

I split students into groups of 3-4 to look over the articles, then we come back together as whole class for the discussion. It is interesting to see what the different groups pick up on.

I bring my tablet to take notes on during the discussion, then post that on the CMS as well.

I have posted the discussion summary from this spring.

Links to the article I used for the abstract writing assignment and the articles I used for the in-class discussion are below.

Time Required: 
30-45 minutes
26 Mar 2018

Identifying Isomers

Submitted by Anne Bentley, Lewis & Clark College
Evaluation Methods: 

I did not require students to turn in their worksheets, but I did circulate to answer questions and confirm their pairings.

Evaluation Results: 

All my groups were able to identify the pairs.  I think learning the labels is harder.

Description: 

This in-class activity can be used to teach structural (or constitutional) isomers. This worksheet presumes that students have already had some experience with transition metal complexes such as determining metal oxidation state, recognizing the coordination sphere, and converting between formulas and structures.

Learning Goals: 

A student should be able to

  • recognize pairs of ionization, coordination, and linkage isomers
  • describe the difference between ionization, coordination, and linkage isomers
Subdiscipline: 
Equipment needs: 

none

Prerequisites: 
Corequisites: 
Topics Covered: 
Implementation Notes: 

I developed this short in-class activity this spring to take the place of a lecture on the topic. The students had already spent a couple of days learning about coordination complexes and stereoisomers. I handed out the in-class activity and asked them to work in groups of 2-3.  I circulated to answer questions, and after about 5-10 minutes of work, I brought everyone back together and summarized the categories. I chose not to give them any introduction to structural isomers in the hopes that by working through the activity, the students would develop their own understanding of the types of isomers.

Time Required: 
10-15 minutes
22 Jan 2018

Streamlining Lab Report Grading: Errors Checklists

Submitted by Sabrina G. Sobel, Hofstra University
Evaluation Methods: 

Errors Checklists are most effective when you list the most common errors with explanations. You will see if you are successful if you use the items on the checklist repeatedly in your grading. Students will better understand their grades because of the clear communication of their errors. You should see a reduction of student inquiries as to why a certain grade was assigned on lab work.

Evaluation Results: 

My students really appreciate the errors checklists because my expectations and my grading choices are made clear. I have found that the formulation of Errors Checklists cause me to focus on and articulate the most common students errors; I subsequently pay more attention to the items in my pre-lab lectures, and student misunderstanding has decreased.

Description: 

I present a format for more effective communiction of errors in lab reports to students that I term Errors Checklists. Grading lab reports are one of the banes of our existence as professors. They are endless, unremitting papers that need to be scrutinized for accuracy, precision and understanding. Instead of tearing your hair out at the fifteenth report in which the student failed to use to proper number of significant figures, or failed to produce a readable graph, why not just breezily check a box on your Errors Checklist (in which you have provided a complete and thoughtful explanation), and staple to the student report?

I have created and used Errors Checklists for General Chemistry and Foundations of Inorganic Chemistry lab classes for almost two decades. I have passed them on to junior colleagues in my department, which they have modified to suit their needs. Errors Checklists lower my anxiety and anger when grading multiple lab reports, and provide clearer communication with students.

Corequisites: 
Prerequisites: 
Topics Covered: 
Learning Goals: 

1. More effective communication of student errors on lab reports.

2. Streamline lab report grading to enable quick turnaround to students.

3. Better communicate expectations on lab reports to enable students to improve performance during the semester.

Equipment needs: 

None.

Implementation Notes: 

You need to develop your own Errors Checklists customized for the experiments in your curriculum. A template is provided. I have included two example checklists; the first is for a Chemical Kinetics lab in which students determine the orders WRT iodide and peroxide for the iodine clock reaction. The second is for the synthesis of potassium alum from aluminum foil, with supplemental analysis of the unit cell (available online).

Time Required: 
not applicable
18 Jan 2018

Isomerism in Coordination Complexes

Submitted by Anthony L. Fernandez, Merrimack College
Evaluation Methods: 

Although students submit their answers in the spreadsheet, I do not grade their answers becuase they worked on this exercise in groups. I usually move through the class and interact with the groups to see how they are progressing.

Evaluation Results: 

This is a relatively simple exercise and students have little trouble coming up with the correct answers for these structures. They sometimes have an issue determining the names of the linkage isomers, especially for the SCN- ligand.

Description: 

Students are confronted with a number of new types of isomerism as they move from organic chemistry into inorganic chemistry. This can be confusing and students often have trouble visualizing structures and differentiating between isomers. In this exercise, students are asked to examine a number of different crystal structures from the Teaching Subset (distributed with Mercury version 3.10, early 2018) of the Cambridge Structural Database. Students have to identify the type of isomerism (geometric, linkage, or optical) exhibited by a complex and then identify the specific isomer (cis/trans, mer/fac, R/S, etc.) observed in the structure.

Learning Goals: 

After completing this exercise, students should be able to:

  • access structures from the CCDC using their web-based form,
  • visualize the structures using Mercury or other viewer,
  • identify the type of isomerism observed in a structure, and
  • determine the correct form of the isomer (e.g. cis or trans).
Corequisites: 
Equipment needs: 

A computer is required to access the Teaching Subset of the Cambridge Structural Database in one of the following ways.

  1. The freely available viewer (Mercury) can be downloaded from the CCDC [https://www.ccdc.cam.ac.uk/Community/csd-community/FreeMercury/]. The CSD Teaching Subset is included with this download.
  2. Students may also access the structures online from the Cambridge Crystallographic Date Centre. Structures can be accessed via a web-based form [https://www.ccdc.cam.ac.uk/structures/] or via the Teaching Subset page on the CCDC website [https://www.ccdc.cam.ac.uk/structures/search?compound=Teaching%20Subset]. These pages also work on a tablet.
Prerequisites: 
Implementation Notes: 

I have used this exercise as an in-class exercise and and out-of-class assignment and it works equally well in both formats. If this is one of the first times that your students will be using Mercury, then I would suggest employing this as an in-class activity. While in class, I have students work in pairs to complete this exercise.

I usually send out the spreadsheet and have students enter their responses and then return the spreadsheet to me. I have also pushed this out as a Google Sheet and had them fill it out online. I find that it is easier to keep track when using the Google Sheet. (We are a Google campus so I am guaranteed that all of my students have a Google account and can access the G Suite of programs.) If you would like the Google Sheet version of this exercise, please contact me and I will share it with you.

In the spreadsheet, there is a sheet titled "Drop-down list info" and the information on this sheet populates the drop-down lists in the "Isomerism" sheet. This sheet needs to be present for the drop-down lists to work.  I usually hide this sheet before distributing the file to my students and I have included instructions how to do this on the sheet.

Time Required: 
30 minutes
17 Jan 2018

Metal Tropocoronand Complexes

Submitted by Anthony L. Fernandez, Merrimack College
Evaluation Methods: 

I assess the student learning by the quality of the discussion generated by this exercise.

Evaluation Results: 

I have used this exercise several times, but I am reporting the results from the Fall 2017 semester.

Students accessed the structures, measured the bond angles using Mercury, and calculated the tau4' values without any difficulties (questions 1 and 2).

When they got to the third question, they could describe what they observed, but struggled with the language. They were very concerned about how to name the observed structures. They were not satisfied with using the terms "distorted square planar" and "distorted tetrahedral" to describe the structures. (This then led into the discussion of the tau4' values and why focusing on the names of the strucutres was limiting.)

All of my students were also able to calculate the LFSE values for the Ni(II) center in the four geometries. They asked about the spin state, but I prodded them to talk it through themselves and think back to previous discussions. They quickly realized that for some of the geometries there is no difference between the HS and LS configurations. They decided to calculate the LFSE for both configuations when they were different. Once their calculations were complete, the students determined that square planar should be the preferred geometry based upon the LFSE.

The last question is the one that threw a monkey wrench into what they thought they knew. They were surprised that a d8 metal center would adopt a tetrahedral geometry since this was contrary to what they had originally learned. I then asked about what other influences would impact the observed geometry. About half of my students said that the steric repulsion of the four donor atoms (and other atoms in the tropocoronand ligand) in a square planar arrangement was greater than that in a tetrahedral arrangement. These students were then able to make the connection to the fact that this must outweigh the LFSE value and favor the geometric transition of  the nickel center.

Description: 

This exercise looks at the metal complexes of tropocoronand ligands, which were first studied by Nakanishi, Lippard, and coworkers in the 1980s. The size of the metal binding cavity in these macrocyclic ligands can be varied by changing the number of atoms in the linker chains between the aminotroponeimine rings, similar to crown ethers. These tetradentate ligands bind a number of +2 metal centers (Cd, Co, Cu, Ni, and Zn) and the geometry of the donor atoms around the metal center changes with the number of atoms in the linker chains. This exercise focuses on the tropocoronand complexes of Ni(II) and students are asked to quantitatively describe the geometry around the metal using the tau4' geometric parameter. This then leads to a discussion of the factors that influence the geometric arrangement of ligands adopted by a metal center. This exercise is used to introduce the concept of flexible metal coordination geometries in preparation of the discussion of metal binding to biological macromolecules and the entatic effect.

Learning Goals: 

After completing this exercise, a student should be able to:

  • access structures from the CCDC using their online form,
  • measure bond angles in a crystal structure using appropriate tools,
  • calculate the tau4' value for a four-coordinate metal center,
  • calculate the ligand field stabilization energy for a complex in a number of different geometries,
  • identify the factors that influence the geometry arrangment of ligands around a metal center, and 
  • explain how the interplay of these factors favor the observed geometry. 
Equipment needs: 

Students will need to have access to the CIF files containing the structural data. These files are part of the Cambridge Structural Database and can be accessed through that if an institutional subscription has been purchased. 

Students can also access these CIF files by requesting the structures from the Cambridge Crystallographic Data Centre (CCDC). The identifiers provided in the faculty-only files can be submitted using the "Access Structures" page (https://www.ccdc.cam.ac.uk/structures/) and the associated CIF files can be viewed or downloaded. Students can then measure the bond angles in the JSmol viewer or in Mercury (which is freely available from the CCDC) after downloading the files.

The CIF files for the copper complexes were not available in the CSD, so I created those CIF files from data found in the linked article.

Prerequisites: 
Corequisites: 
Subdiscipline: 
Implementation Notes: 

I have used this activity in a two different ways.

  • In the past, I have assigned this as a homework assignment and have had students complete questions 1-4 outside of our class meeting time. They requested the structures from the CCDC or used our copy of the CSD on their own time. I then facilitated a dicussion of their answers before discussing the last question as a group in class. This approach worked well.
  • This year, I decided to use this exercise as an in-class group activity. I began class with a discussion of geometric indices using the presentation that is also available on the VIPEr site and is included in the "Related activities" section. I then broke my class up into groups of three students and had each group work through the activity. After the students completed the exercise, I then shared the calculations that I did for the zinc complexes so that they could remove the complication of the LFSE values from the discussion. I was much happier with this approach because I was able to focus the discussion a bit more and use the zinc data to reinforce the overall point of the exercise.

Note that in the original articles, the dihedral angle "between the two sets of planes defined by the nickel and two nitrogen atoms of the troponeiminate 5-membered chelate rings" was reported. I have decided to use the more current tau4' parameter in this exercise.

Time Required: 
45-60 minutes

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