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. 

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
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
31 Jul 2017

Inorganic Nomenclature: Naming Coordination Compounds

Submitted by Gary L. Guillet, Armstrong State University
Evaluation Methods: 

For my course I grade this assignment as a problem set.  Upon collecting the assignment I do not exhaustively grade them.  I check them over for completness.  I tell the students when I hand it out that it is designed for them to learn and then test their own comprehension and if they are stuck they should bring issues to office hours. 

On the following exam I put two or three inorganic complex names and have the students draw the structures.  The test questions always incorporate isomerism in addition to combinations of common ligands and transition metals.

Evaluation Results: 

After completion of this assignment most students are able to draw straigthforward structures including some isomers on an exam.  They can identify common ligands from their names like water, ammonia, carbon monoxide.  They also understand the common conventions in naming including handling cis and trans isomers as well as fac and mer isomers.

In the most recent sample of ACS examinations (IN16D) 87% of my students answerd correctly on the question most directly related to this assignment, selecting the correct name of a given complex using a picture of the complex.  I do not have any comparative data from another teaching approach.

Description: 

I do not like to take a large amount of time in class to cover nomenclature of any kind though I want students to know the names of common ligands and the basic ideas of how coordination complexes are named.  Since it is a systematic topic I assign this guided inquiry worksheet.   The students complete it outside of class and can work at whatever pace they want.  If they are more familiar with the topics the can quickly complete it but if they are rusty or have not seen some of the material it gives them an easy entry point to ask questions to fill in any gaps in their knowledge.  This assignment covers determing charge on a metal in a complex with simple ligands, how to identify and name common isomers, and it is structured in a guided inquiry form. 

Learning Goals: 

Students will be able to identify and correctly name common ligands in a chemical structure or chemical name.

Students will be able to identify the charge on a metal or a ligand in a chemical structure.

Students will be able to identify common isomeric differences in a chemical structure or a chemical formula (cis, trans, fac, mer). 

Students will be able to use a chemical name to draw a chemical structure.

Equipment needs: 

None

Topics Covered: 
Corequisites: 
Prerequisites: 
Implementation Notes: 

I use this assignment to replace a lengthy lecture on the topic of nomenclature when covering coordination chemistry.  I have students complete this assignment outside of class.  I encourage them to work in pairs so students can jointly interpret the instructions and determine the patterns in naming complexes.  The assignment is constructed in a very straightforward manner and covers the basics of inorganic nomenclature.

Upon completion of the assignment I take about 15-20 minutes in class to quickly cover the main ideas of the assignment.  I field any questions that arose during the assignment and I do a few comprehension check type questions on the board. 

Time Required: 
1-2 hours
3 Jun 2017
Evaluation Methods: 

Evaluation methods could include grading as an in-class worksheet, trading with a partner for peer grading or turned in as an out-of-class graded homework assignment.

Evaluation Results: 

Currently, this activity has not been tested in a classroom.  Please post how your students did!

Description: 

This in-class activity is designed to assist students with the visualization of solid-state close-packed structures, using metal-sulfide nanocrystalline materials as a an example system.  Students will be asked to visualize and describe both hexagonal closest packed (hcp) and cubic closest packed (ccp) structure types, and isolate the tetrahedral and octahedral holes within each structure type.  Lasty, students will be asked to compare and contrast four metal-sulfide unit cells discussed in the paper below.

 

Powell, A.E., Hodges J.M., Schaak, R.E. Preserving Both Anion and Cation Sublattice Features during a Nanocrystal Cation-Exchange Reaction: Synthesis of a Metastable Wurtzite-Type CoS and MnSJ. Am. Chem. Soc. 2016, 138, 471-474.

http://pubs.acs.org/doi/abs/10.1021/jacs.5b10624

Learning Goals: 

In answering these questions, a student will…

  •  ...develop stronger visualaztion skills for extended, solid state materials;
  •  ...compare the packing sequence of close packed structures;
  •  ...locate tetrahedral and octahedral holes in close packed systems;
  •  ...count the number of tetrahedral / octahedral holes relative to the lattice ions; and
  •  …determine the number of atoms in a unit cell.
Equipment needs: 

The use of software - such as the demo version of CrystalMaker (http://www.crystalmaker.co.uk) or StudioViewer (Esko - app stores) - will be really helpful. StudioViewer can be run on cell phones, tablets, or MacOS devises. CrystalMaker is available for both Mac and PC. 

Instructions on using Studio Viewer to visualize structures on mobile devices are available in the learning object, Visualizing solid state structures using CrystalMaker generated COLLADA files.

 

Corequisites: 
Prerequisites: 
Implementation Notes: 

This learning object was developed at the 2017 MARM IONiC workshop on VIPEr and Literature Discussions. It has not yet been implemented.

This could be assigned for homework, but would likely work better in class with guidance. 

Time Required: 
This will probably take 50 minutes depending on how much work with models you do.
3 Jun 2017

Literature Discussion of "A stable compound of helium and sodium at high pressure"

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

Students could be evaluated based on their participation in the in-class discussion or on their submitted written answers to assigned questions.

Evaluation Results: 

This LO has not been used in a class at this point. Evaluation results will be uploaded as it is used (by Spring 2018 at the latest).

Description: 

This paper describes the synthesis of a stable compound of sodium and helium at very high pressures. The paper uses computational methods to predict likely compounds with helium, then describe a synthetic protocol to make the thermodynamically favored Na2He compound. The compound has a fluorite structure and is an electride with the delocalization of 2e- into the structure.

This paper would be appropriate after discussion of solid state structures and band theory.

The questions are divided into categories and have a wide range of levels.

Dong, X.; Oganov, A. R.; Goncharov, A. F.; Stavrou, E.; Lobanov, S.; Saleh, G.; Qian, G.-R.; Zhu, Q.; Gatti, C.; Deringer, V. L.; et al. A stable compound of helium and sodium at high pressure. Nature Chemistry 2017, 9 (5), 440–445 DOI: 10.1038/nchem.2716.

Corequisites: 
Learning Goals: 

After reading and discussing this paper, students will be able to

  • Describe the solid state structure of a novel compound using their knowledge of unit cells and ionic crystals
  • Apply band theory to a specific material
  • Describe how XRD is used to determine solid state structure
  • Describe the bonding in an electride structure
  • Apply periodic trends to compare/explain reactivity
Implementation Notes: 

The questions are divided into categories (comprehensive questions, atomic and molecular properties, solid state structure, electronic structure and other topics) that may or may not be appropriate for your class. To cover all of the questions, you will probably need at least two class periods. Adapt the assignment as you see fit.

CrystalMaker software can be used to visualize the compound. ICE model kits can also be used to build the compound using the template for a Heusler alloy.

Time Required: 
2 class periods
3 Jun 2017

An ion exchange method to produce metastable wurtzite metal sulfide nanocrystals

Submitted by Janet Schrenk, University of Massachusetts Lowell
Evaluation Methods: 

Evaluation methods are at the discretion of the instructor. For example, you may ask students to provide written answers to the questions, evaluate whether they participated in class discussion, or ask students to present their answers to specific questions to the class.

Description: 

In this literature discussion, students use a paper from the literature to explore the synthesis, structure, characterization (powder XRD, EDS and TEM) and energetics associated with the production of a metastable wurtzite CoS phase. Students also are asked define key terms and acronyms used in the paper; identify the goal of the experiments and determine if the authors met their goal. They examine the fundamental concepts around the key crystal structures available.  

 

Preserving Both Anion and Cation Sublattice Features during a Nanocrystal Cation-Exchange Reaction: Synthesis of a Metastable Wurtzite-Type CoS and MnS

Powell, A.E., Hodges J.M., Schaak, R.E. J. Am. Chem. Soc. 2016, 138, 471-474.

http://pubs.acs.org/doi/abs/10.1021/jacs.5b10624

 

There is an in class activitiy specifically written for this paper. 

Corequisites: 
Prerequisites: 
Learning Goals: 

In answering these questions, a student will be able to…

  • define important scientific terms and acronyms associated with the paper;

  • describe the rocksalt, NiAs, wurtzite, and zinc blende in terms of anion packing and cation coordination;

  • differentiate between the structure types described in the paper;

  • explain the difference between thermodynamically stable and metastable phases and relate it to a free energy diagram; and

  • describe the structural and composition information obtained from EDS, powder XRD, and TEM experiments.

Implementation Notes: 

This learning object was created at the 2017 IONiC Workshop on VIPEr and Literature Discussion. It has not yet been used in class.

Time Required: 
50 minutes
3 Jun 2017
Evaluation Methods: 

This LO was craeted at the pre-MARM 2017 ViPER workshop and has not been used in the classroom.  The authors will update the evaluation methods after it is used.

Description: 

This module offers students in an introductory chemistry or foundational inorganic course exposure to recent literature work. Students will apply their knowledge of VSEPR, acid-base theory, and thermodynamics to understand the effects of addition of ligands on the stabilities of resulting SiO2-containing complexes. Students will reference results of DFT calculations and gain a basic understanding of how DFT can be used to calculate stabilities of molecules.

 
Prerequisites: 
Corequisites: 
Learning Goals: 

Students should be able to:

  1. Apply VSEPR to determine donor and acceptor orbitals of the ligands

  2. Identify lewis acids and lewis bases

  3. Elucidate energy relationships

  4. Explain how computational chemistry is beneficial to experimentalists

  5. Characterize bond strengths based on ligand donors

Course Level: 
Implementation Notes: 

Students should have access to the paper and have read the first and second paragraphs of the paper. Students should also refer to scheme 2 and table 2.

 

This module could be either used as a homework assignment or in-class activity. This was created during the IONiC VIPEr workshop 2017 and has not yet been implemented.

 
Time Required: 
50 min
3 Jun 2017

Quantum Dot Growth Mechanisms

Submitted by Chi Nguyen, United States Military Academy
Evaluation Methods: 

The question document attempted by students in preparation for the literature discussion will be due prior to the in-class discussion. In particular, students' performance on the particle-in-a-box question will be evaluated to assess retention from the previously covered course material. The next exam following the discussion will contain specific question(s) (data/figure analysis) addressing these topics. Students' performance difference between the two will be evaluated. The extent to which students improve their post-discussion understanding of the concepts will direct future implementation.

Evaluation Results: 

To be determined. This is a newly proposed literature discussion.

Description: 

This literature article covers a range of topics introduced in a sophomore level course (confinement/particle-in-a-box, spectroscopy, kinetics, mechanism) and would serve as a an end-of-course integrated activity, or as a review activity in an upper level course. The authors of the article employ UV-vis absorption spectroscopy of CdSe quantum dots as a tool to probe the growth mechanism of the nanoparticles, contrasting two pathways.

 

Reference:  DOI 10.1021/ja3079576 J. Am. Chem. Soc. 2012, 134, 17298-17305

 
Corequisites: 
Prerequisites: 
Learning Goals: 

Apply the particle in a box model to interpret absorbance spectra with respect to nanoparticle size.

 

Analyze the step-growth and living chain-growth mechanisms proposed in this paper.

 

Evaluate the kinetics as it applies to the step-addition.

 

Recognize and apply multiple scientific concepts in an integrative manner.
Implementation Notes: 

Sophomore level implementation:  Recommend focusing on select portions (e.g. Figures 1b, 2, 5 with corresponding text) of the paper rather than having students read the entire document.  The learning objects focus on select topics, such as particle-in-a-box, reaction mechanism, and kinetics in conjunction with absorbance spectroscopy.  This would be a good literature discussion resource for an end-of-course integrative experience that encompasses multiple topics from general chemistry and inorganic chemistry.  

 

Advance level implementation:  For an upper division course, incorporate the paper in its entirety early in the course as an assessment on students’ ability to integrate multiple concepts that they should have learned in general chemistry, organic chemistry, and physical chemistry.  To enhance the experience, accompanying the literature discussion on this paper with a laboratory experience by repeating the experimental and characterization procedures presented in the paper, and having students' compare their results with published results.  This also serves to enhance students’ scientific literacy by critically assessing the quality of the paper.

 

Excerpts of the paper and questions can be used on a graded event, or as lesson preparation for in class discussion.

 
Time Required: 
In-class discussion takes approximately 50 minutes with students having already read the paper and submitted their responses to the questions.

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