Coordination Chemistry

22 Aug 2015

Antibacterial Reactivity of Ag(I) Cyanoximate Complexes

Submitted by Kari Young, Centre College
Evaluation Methods: 

We assessed student learning using formal reports, informal reports, and oral presentations. 

Evaluation Results: 

In general, students are able to prepare and characterize the complexes.  IR spectroscopy is especially useful in this lab because 1H NMR spectroscopy is not very diagnostic. One difficulty is removing excess solvent from the ligand, and we recommend using a mechanical vacuum pump after rotovapping. 

Some students are uncomfortable managing the amount of data this project generates when students share data for more than one compound. This project is a good opportunity to discuss using tables effectively.

Additionally, evaluating the "best" complex requires students to weigh a variety of parameters including heat stability and cost in addition to the antimicrobial activity.

Some students are also uncomfortable sharing data with their classmates or using others' data. This project provides a good opportunity to talk about the ways in which scientists collaborate.

Some but not all students report that they really enjoy the microbiology/biomedicine application.  

Description: 

In this experiment, students will synthesize and characterize one of three Ag(I) cyanoximate complexes as potential antimicrobial agents for use in dental implants. This experiment combines simple ligand synthesis, metalation and characterization, and a biomedical application. The complexes are both air and light stable. Students apply the Kirby-Bauer disk diffusion test, a common microbiology assay, to determine the antibacterial properties of their complexes. Students will also perform a simple cost analysis as part of the evaluation of the complexes.  This experiment was designed during the June 2015 “Improving Inorganic Chemistry Pedagogy” workshop funded by the Associated Colleges of the South.

Prerequisites: 
Learning Goals: 

A student should be able to:

  • Prepare one of a series of Ag(I) cyanoximate complexes and perform appropriate characterization of identity and purity
  • Measure antimicrobial activity in a semi-quantitative way using the Kirby-Bauer assay, including design and implementation of appropriate control experiments.
  • Evaluate a series of complexes as potential antimicrobials for dental applications based on the criteria of heat stability, water insolubility, and antibacterial activity.
  • Identify most cost effective complex.
Equipment needs: 

FT-IR spectrometer

NMR spectrometer

Melting point apparatus

Microbiology equipment

Implementation Notes: 

In this experiment, students connect organic synthesis, inorganic synthesis, and applications in microbiology in a multiweek experiment.

 

Students synthesize one of three possible derivatives of a cyanoxime ligand, coordinate Ag(I), and test the antimicrobial properties of their compound. The antimicrobial assay requires supplies not commonly found in a chemistry laboratory, and instructors are encouraged to collaborate with a colleage in microbiology.

 

This experiment has been tested several times since it was first developed in 2015. Additional notes were added in January 2020. We welcome others in the VIPEr community to help us test this experiment. If you do try it, please consider posting your comments or filling out our evalution survey:

 

Time Required: 
Four 3-hour lab sessions
10 Aug 2015

A Demonstration to Segue Between d to d and CT Transitions

Submitted by Marion E. Cass, Carleton College
Evaluation Results: 

Students easily associate intensity of color with the concentration of a solute from their work in previous general chemistry and analytical chemistry courses.  My goal in this exercise is to have them learn that the magnitude of the molar extinction coefficient is a measure of the intensity of the absorption and a function of the quantum mechanical allowedness of the transition. Physically observing the relative intensity of three solutions of the same concentration forces them to struggle with the concept of intensity of an absorption in contrast to the concept of the color that results from the energy of that absorption(s).  In the faculty only files I have included an exam question I have given to evaluate student comprehension of this concept.  This is a question I aspire for 100% perfect scores, however my data show that 3 students in a class of 15 (so around 20%) did not get a perfect score on this problem.

Description: 

The following is a simple in-class “demonstration” that I use to segue between d to d and charge transfer transitions.  After teaching about d to d transitions and Tanabe-Sugano Diagrams, I show my students three solutions that I have put in large test tubes before class. The three solutions I place in the test tubes are:

a.  10 ml of 0.1M Co(H2O)62+

b.  10 ml of 0.1M Cu(H2O)62+

c.  10 ml of a freshly prepared 0.1 M KMnO4 solution

We review what we have learned about using Tanabe Sugano diagrams to predict the maximum number of possible d to d transitions that could  be observed for a given metal ion (with a given oxidation state, d electron configuration, and proposed high or low spin state) in the visible spectrum that give rise to color.   

We then use observations of the KMnO4 solution to segue to the discussion of a different type of electronic transition: Charge Transfer.

I have also included an exam question that could be used to evaluate student understanding of the concept highlighted in the demonstration.

 
Learning Goals: 

Demonstration to Segue Between d to d and CT Transitions

 

Learning Objectives:  Going into this exercise:

1.  Students should be able to determine the oxidation state and d electron count for a given set of metal complexes.

2.  Students should be able to propose whether a metal complex should be high or low spin (or state whether high and/or low spin are irrelevant designations) for a given metal d electron configuration.

3.  If they have learned about Tanabe-Sugano diagrams, students should be able to propose the maximum number of d à d transitions that could be observed for a given metal ion with a given d electron configuration and a given LS or HS designation.

3.  Students should be able to visually compare three solutions of different metal complexes with the same concentration and recognize that they vary in color as well as intensity.

 

Following the Demonstration:

Students should be open minded and prepared to learn about why many transition metal complexes have the beautiful and intense colors that they do (over and beyond the color imparted by d to d transitions that fall in the visible).

Course Level: 
Corequisites: 
Time Required: 
20 minutes to prepare the demonstration, 10 minutes in class before beginning a section on CT transitions
2 Jul 2015
Evaluation Methods: 

Students can hand in tthe first set of questions as homework which may be evaluated.  Class participation and group work may also be graded appropriately.

Evaluation Results: 

This is an untested LO.

Description: 

This learning object is based on discussion of the literature, but it follows a paper through the peer review process.  Students first read the original submitted draft of a paper to ChemComm that looks at photochemical reduction of methyl viologen using CdSe quantum dots.  There are several important themes relating to solar energy storage and the techniques discussed, UV/vis, SEM, TEM, electrochemistry, and catalysis, can be used for students in inorganic chemistry.

Unlike a typical literature LO where students discuss only the current science, this LO contains the actual reviewer comments to the original submitted manuscript as well as a link to the final version that was published in Journal of Materials Chemistry A.

DOI: 10.1039/C5TA03910J

Prerequisites: 
Learning Goals: 

Students will be able to...

·  Communicate the main ideas of a scientific research paper to classmates.

·  Identify the research area, importance of the research, and background information provided in a scientific paper.

·  Discuss areas of a paper that may be improved through revision.

·  Compare their views of necessary revisions with actual anonymous reviewers on a scientific paper and the eventual publication.

·  Understand the importance and shortcomings of the peer review process using an actual publication from the literature.

Implementation Notes: 

The LO has multiple sections which may be discarded or edited depending on the particular learning goals desired.  While the chemistry may be difficult for lower level students, the discussion of the peer review process may be valuable to students across multiple levels and even in writing courses.  Also provided are the authors' actual responses to the reviewers comments.  It should also be noted that the original article was submitted to ChemComm, but the subsequent revised article was submitted and accepted to Journal of Materials Chemistry A.

Time Required: 
Homework Assignment + 1 h in class
2 Jul 2015
Evaluation Methods: 

Options for assessment include:

  • Students can complete the questions and submit their responses which are then evaluated for clear understanding of the concepts (For example: Is the student able to describe clearly the purpose behind the paper?)
  • Students can be evaluated for the quality of their contributions to in-class discussion (Is it evident that the student read the paper?)
  • Students can be asked follow up questions on a later exam (Can the student recall the basic principles discussed in the activity?)
Evaluation Results: 

We have no results at this time for this newly created activity.  If you use this object in Fall 2015, please post comments to this LO so we can include yours results!

Description: 

This literature discussion is meant to give students an understanding of both the key concept-driven and more “meta” information of a literature paper.  Students will use Jillian Dempsey’s paper, “Electrochemical hydrogenation of a homogeneous nickel complex to form a surface-adsorbed hydrogen-evolving species,” to investigate paper authorship, how the scientific method is used in research, and how to understand the important findings of a research article.

 

Reference: Chem. Commun., 2015, 51, 5290-5293

DOI:10.1039/C4CC08662G

 

For a general chemistry course, questions 1-4, 7, and 10 could be utilized to expose students to the format of literature articles without diving too deeply into content.

 

For an advanced inorganic course, all questions could be used to include some introductory content to the discussion.

 

This learning object was developed at the 2015 NSF sponsored cCWCS VIPEr workshop at University of Washington where we were fortunate to hear Prof. Jillian Dempsey present this research. It is worth mentioning that the first author of this paper was an undergraduate student at UNC-CH. The Dempsey’s research lab focuses on developing new technology to support a solar energy economy through catalysis.

Corequisites: 
Prerequisites: 
Learning Goals: 

After completing this activity, the student will be able to:

  • access different parts of a paper and its supplementary information for different levels of understanding.
  • use information in a paper to determine the intent behind published research and how it fits into a larger purpose.
  • see that chemical research builds on earlier work and is an iterative process in which direction can change based on new information.
  • understand the difference between homogenous and heterogeneous catalysis
  • identify and define inorganic chemistry related terms
Implementation Notes: 

The first author of this publication, Daniel J. Martin is an undergraduate student!  It may be worth mentioning this fact to the students and to help them understand that in the academic world publications are the “currency” needed for career advancement.  We envision that the students will receive a copy of the article as well as the student handout containing the discussion questions several days prior to the discussion.  The faculty member may also choose to omit one or more questions from the student handout and only ask them during the discussion period.

Time Required: 
0.5-1.5 hours
2 Jul 2015
Evaluation Methods: 
Options for assessment include: 
  • Students can complete the questions and submit their responses, which are then evaluated for clear understanding of the concepts. (Is the student able to describe clearly the chemistry in the paper?) 
  • Students can be evaluated for the quality of their contributions to in-class discussion. (Is it evident that the student has read the paper?)
  • Students can be asked follow up questions on a later exam. (Can the student recall and apply the principles discussed in the activity to a similar problem?) 
Evaluation Results: 

We have no results at this time for this newly created activity.  If you use this object in Fall 2015, please post comments to this LO so we can include your results!

Description: 
The paper entitled “Electrochemical hydrogenation of a homogeneous nickel complex to form a surface adsorbed hydrogen-evolving species” explores the discovery, characterization and catalytic activity of a film that deposited on the electrode while studying a nickel complex under electrocatalytic conditions.
 
This literature discussion includes several sets of questions that address different aspects of the paper, as described in the implementation notes. Discussion questions cover the structure and electron configuration of the compounds used to form catalysts, their synthesis and reactivity, the formation and activity of the catalytic film, electrocatalysis using cyclic voltammetry, and the characterization of the catalytic film.  The list of questions is extensive, but we encourage you to review them and select the ones that will best fit the goals of your lesson. 
 
This learning object was developed at the 2015 NSF sponsored cCWCS VIPEr workshop at University of Washington where we were fortunate to hear Prof. Jillian Dempsey present this research. It is worth mentioning that the first author of this paper was an undergraduate student at UNC-CH. The Dempsey’s research lab focuses on developing new technology to support a solar energy economy through catalysis. 
 
Reference: Chem. Commun., 201551, 5290-5293 DOI: 10.1039/c4cc08662g
 
Several questions of the discussion focus on data found in the supporting information. 
Corequisites: 
Learning Goals: 
By completing this activity, the student will be able to:
  • Identify the difference between facial and meridional geometries.
  • Apply 18 electron counting rules to a transition metal complex.
  • Apply electrochemical concepts to describe qualitative features of a cyclic voltammogram trace.
  • Apply knowledge of redox chemistry to understand electrocatalysis.
  • Demonstrate an understanding of reduction and oxidation reactions as they relate to transition metal complexes.
  • Use retrosynthetic analysis to determine which starting materials are needed for a Schiff base product.
  • Understand what a hydrogenation reaction is and show what happens to a double bond when it is hydrogenated.
  • Understand the use of SEM (Scanning Electron Microscopy) and TEM (Transmission Electron Microscopy) images to characterize a film. 
  • Understand the use of XPS (X-ray Photoelectron Spectroscopy) and EDS (Electron Dispersion Spectroscopy) to elucidate the elemental composition of a film.
Implementation Notes: 
It may help to split this activity and assign portions to groups of students. Or it may be better to spread the questions out over several weeks of the course, as relevant topics present themselves in the course content. For reference, the questions are split into groups below. You may also choose to eliminate certain groups of questions if they do not align with the covered content of your course. Also, a suggested exam question is included separately.
 
Questions 1-3. The structure and electronic configuration of two octahedral nickel(II) complexes. Includes basic concepts on coordination chemistry like isomerism, coordination geometry, oxidation state, and the 18 electron rule.
 
Questions 4-9. Synthesis and reactions of the organic ligands coordinated to nickel. Includes imine chemistry and the concepts of hydrogenation, hybridization, and aromaticity.
 
Questions 10-15. Electrochemical deposition of a film and its catalytic activity to produce hydrogen. Electrocatalysis and hydrogen evolution. Includes topics of cyclic voltammetry, overpotential, reversible and irreversible reductions. 
 
Questions 16-17. Discussion of methods used in the paper: CV, imaging (SEM and TEM) and spectroscopic techniques (XPS and EDS) and how XPS was used to characterize the film . Question 16 is particularly amenable to division among groups of students.
 
Suggestions for exam questions (faculty handout only). The provided exam question would be used to assess students after they have completed the in-class discussion. If very specific details about the mechanism behind the voltammetric response are desired then students may benefit from access to a clean version of the paper during the exam, 
 
This activity has not yet been tested. If the in-class discussion is to fit within 50 minutes, then several questions need to be left out of the discussion, though the students still need to do them to prepare for the discussion. Also, closely related questions can be addressed together. For example, questions 1, 2, and 6 are primarily intended to review concepts that the students need to answer questions 3, 4-5,  and 7-8. Question 9 deals with organic retrosynthetic analysis and is not essential for the questions that follow. Questions 10-13 deal with the heart of the paper, and questions 14-17 deal with controls and characterization of the system. The instructor's priorities should determine whether only the most critical questions (such as 3-5, 7-8, 10-13, and perhaps 14 and 15) are each briefly discussed in one fifty class period, or if at least half of two class periods are used for a more extensive discussion.
 
 
The activity uses some figures from the paper itself. The paper was published under a Creative Commons Attribution-NonCommercial 3.0 Unported (CC BY-NC 3.0) license as described below:
 
Time Required: 
Untested. A selection of key questions could be discussed in one 50 minute session (see implementation notes). Otherwise, the activity could take over 90 minutes.
1 Jul 2015

Advanced Inorganic Chemistry Course Videos

Submitted by Kathryn Haas, Saint Mary's College, Notre Dame, IN
Evaluation Methods: 

3 x 1 hour exams, ACS INorganic Chemistry Final Exam.

Description: 

At this website, you will find a link to the syllabus and all lecture videos for a "flipped" version of an Advanced Inorganic Chemistry Course taught at Saint Mary's College (Notre Dame, IN).  I used Shiver & Atkins for this course, and the format is based off of Dr. Franz's course at Duke.  If anyone is interested in the problem sets, I will be happy to share, although much of the material I used is from VIPEr.  

Learning Goals: 

Students will be able to apply fundimental principles of Group Theory, M.O. Theory, Acid/Base Theory, Crystal Field Theory, Kinetic & Thermodynamic trends, and 18e- rule  to understand spectroscopic (Absorption, Vibrational) and magnetic properties and to understand bonding and reactivity of metals.

 

Implementation Notes: 

This was the first iteration of a flipped model, I appologise for any mistakes & innacuracies, but if you spot issues, I'm happy to know about them.  The videos are rather long, and I will say that if I do this again, I will certainly design shorter videos!  Students really like it when the videos are 10-15 min or less.  But, perhaps these can help some beginning teachers prepare for class.  (And if that's you, good luck!)

Time Required: 
1 semester, 3 credit hour course
30 Jun 2015
Evaluation Methods: 

Using Automated Response System with questions inserted in PowerPoint lectures and exam questions related to the topic.

Evaluation Results: 

Since using the original questions, I have edited choices.  However, I have used earlier versions in 2011 and 2013.

 

In 2011 (15 students), I used Method 3 for instruction.  The questions that I asked were Q6, and Q11 as written and Q8, Q9 and Q10 with fewer choices.  The results (percentage of students with correct answers, most common answer when it wasn’t the correct one):

preview questions:  Q6 (80), Q8 (60), Q9 (47), Q10 (7, choice #1), Q11 (33).

review questions:  Q6 (92), Q8 (92), Q9 (62).

additional review (after finishing entire chapter):  Q8 (87), Q10 (33, choice #2).

 

I had fewer questions in 2013 (8 students) due to time constraints, but did it in a similar fashion.

preview:  Q9 (0, choices 1&5 tied), Q10 (14, choice #1)

review:  Q8 (100), Q10 (17, choice #1)

Note:  percentages may vary from expected values due to student attendance on a given day.

 

Finally, in 2013, the ACS Inorganic Chemistry Exam was given.  Only ONE question related to the topic.  4 out of 8 students correctly selected the correct answer on the exam.

Description: 

A set of questions to intersperse in lectures OR to use as a means of student guided learning of nomenclature.

Learning Goals: 

In answering these questions, a student will:

review naming and formulas for simple salts;

name coordination complexes;

determine formulas from names of complexes.

Subdiscipline: 
Equipment needs: 

If you do not have a method of polling students online, you can use index cards for answers OR just have students write down answers.

Prerequisites: 
Corequisites: 
Topics Covered: 
Implementation Notes: 

There are a few methods of using polling in classes:

 

1)  As an end of chapter “quiz”  --  this would replace giving a paper quiz;

2)  As a preview set of questions to see what you need to discuss more in a lecture format, followed by lecture and recap questions to see what was learned.  (The recap questions do NOT have to be different questions, but not all of your recap questions need to be used in your preview.)

3)  Ask the question; give students one minute to answer without discussion; show results and have students discuss the question/answer for a few minutes and ask the question again.  If students are still not all correct, discuss what and why the correct answer.

Time Required: 
Method 1 above: 10 - 15 minutes; Method 2: 20 - 30 minutes; Method 3: 50 - 75 minutes (a full class)
29 Jun 2015

Synthesis of Aspirin- A Lewis Acid Approach

Submitted by Kathleen Field, WGU
Evaluation Methods: 

Data sheet for intro level courses along with supplemental questions.  

Lab Reports and supplemental questions for uppper classes.  

 

 

Description: 

This is the procedure for a Fe(III) catalyzed synthesis of aspirin, an alternative to the traditionally sulfuric acid catalyzed synthesis of aspirin.  The prep compares and contrasts the Bronsted acid catalyzed esterification reaction with a Lewis acid iron (III) catalyzed pathway.  This can be used in different courses at different levels, but is it written for a general/intro level chemistry course.    

Prerequisites: 
Learning Goals: 

Intro Chemistry

  • Students will be able to compare and contrast Lewis Acids/Bases with Bronsted Acids/Bases
  • Students will be able to calculate the moles of each reactant, the aspirin product, and the percent yield of product.  
  • Students will be able to determine the limiting reagent and calculate amount of excess material

Organic Chemistry

  • Students will characterize aspirin using melting point determination, IR and NMR spectroscopy and be able to distinguish the different structural elements between the starting material (salicylic acid) and the product (aspirin)
  • Students will be able to differentiate between the Fe(III) catalyzed mechanism and the sulfuric acid catalyzed esterification mechanism

Inorganic Chemistry/upper level

  • Students should be able to relate experimental observations (color) to the d-orbital splitting of Fe(III) complexes
  • Students will be able to draw plausible intermediates and propose a mechanism for the iron catalyzed reaction in relation to the observed reaction colors
Equipment needs: 

Erlenmeyer Flasks, Hot Plate, Balance, Vacuum Filtration, NMR and IR spectroscopy

Chemicals: Acetic Anhydride, FeCl3, Salicylic Acid, Water

Implementation Notes: 

Some notes have been included in the uploaded instructor notes.  

We are interested to submit this to the Journal of Chemical Education, so we (the authors) would be very interested in examining any student data that anyone receives if using the procedure as written in addition to any modifications to the procedure for both general/intro level classes and upper level classes/labs.  

Time Required: 
1-3hr class for intro class, 4 hour class for organic, or longer for upper level classes.
29 Jun 2015

Gummies and Toothpicks Point Group Determination Activity

Submitted by Darren Achey, Kutztown University
Evaluation Methods: 

This activity is graded as a homework assignment.  Full credit is awarded for the correct point group assignment.  If the student misses the point group assignment, partial credit is awarded for the symmetry elements the student found correctly, with an identification of where they deviated from the correct symmetry assignment.

In addition, the exam following this assignment typically has two unique (not one from this assignment) molecules that the students are asked to assign symmetry elements and the point group for. (These vary by semester to ensure that the test questions have not been passed down to the students from prior years)

Evaluation Results: 

Students tend to have trouble recognizing improper rotations without first seeing several examples of this.

Description: 

In this activity, students will use gummies and toothpicks to construct models of molecules that will then be analyzed for their symmetry elements, and ultimately placed into the correct point group and the models can then be consumed.

Learning Goals: 
  • Construct the molecules with the correct VSEPR geometry
  • Observe the symmetry elements present within each molecule
  • Classify each molecule with the correct point group
Subdiscipline: 
Equipment needs: 
  • (Relatively) round, small, and multicolored gummies
  • Toothpicks
Prerequisites: 
Corequisites: 
Course Level: 
Implementation Notes: 

I typically use this as an in-class activity (50 minutes) for a senior level, Advanced Inorganic Chemistry course that has between 10-15 students.  This activity is undertaken immediately after the symmetry elements are introduced and the students have had limited exposure to observing the symmetry elements themselves.  As such, the beginning is often a little slow as they gain confidence in classifying symmetry elements.

I allow the students to work in pairs or at most groups of three and have found this to be an effective way for students to show each other symmetry elements that their partner(s) do not see.  I also encourage students to consider not making a model for some of the molecules so that they can practice their visualization of the molecules in three dimensions.

The students usually cannot finish all of the molecules within the class period so the unfinished molecules become homework.  The final point groups are graded as a homework score for the course.

Alternatively, this exercise could also be completed in a laboratory session of approximately 2 hours.

Time Required: 
50 minutes in class, roughly another hour outside of class.
10 Jun 2015

Web Resources from the 2013 Inorganic Curriculum Survey

Submitted by Barbara Reisner, James Madison University

 

In the 2013 Inorganic Curriculum Survey, respondents were asked about the resources they used when they teach inorganic chemistry. About 20% of respondents selected "other" and provided information about these resources. A number of people mentioned specific websites. This collection consists of the websites submitted in the survey.

Prerequisites: 
Corequisites: 

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