Electrochemistry

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.
29 Jun 2015

Copper Oxide Crystal Growth

Submitted by Ellen Steinmiller, University of Dallas
Evaluation Methods: 

Student answers to the reading comprehension questions were collected at the beginning of class and graded out of 10 points.  An additional 15 points was based on on class participation during the discussion and answers to the in class questions. 

Evaluation Results: 

Overall, students did well on this paper.  During the group problems, students struggled the most with Miller indexes and drawing the layer diagrams of the Cu atoms.  In the future I would incorporate ICE models in the class discussion so that students can more clearly see the different crystal planes.  Students are often quite confused as to why copper oxide is a primitive cubic cell and I think see the models would help with the visualization that not all Cu atoms are created equally.

Description: 

Students in a 2nd year inorganic class read an article describing the effect of additives on the final morphology of copper oxide. (Siegfried, M.J., and Choi, K-S, “Elucidating the Effect of Additives on the Growth and Stability of Cu2O Surfaces via Shape Transformation of Pre-Grown Crystals”J. Am. Chem. Soc., 2006, 128 (32), pp 10356–10357.  dx.doi.org/10.1021/ja063574y). The authors describe a systematic method that exploits the preferential adsorption phenomenon to regulate crystals shapes by observing the shape transformation of pre-grown crystals over time (e.g cubic to rhobooctahedral to octahdral and back).  The authors start with seed crystals of specific morphology and then immerse the pre-grown crystals in a second solutions with additives to direct the crystal growth.    This strategy allowed them to develop a general scheme to determine the relative order of surface energies and form new crystal shapes containing planes that cannot be directly stabilized by preferential adsorption alone.  

Prerequisites: 
Corequisites: 
Learning Goals: 

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

-          Differentiate between notations describing planes, directions, and families of planes

-          Describe atomic surface terminations of different crystal faces of the same unit cell

-          Describe the effect of common additives on synthesis of crystals

-          Determine d-spacings of planes from XRD data

-          Determine lattice parameters from XRD data 

Implementation Notes: 

I used this article in the Spring of 2014 in a class of 9 (1 freshmen, 1 sophomore, 5 juniors, 2 seniors) as our conclusion of our discussion of solid state chemistry.   Students had a background in electrochemistry, crystal structures and x-ray diffraction before reading this paper.  Students were required to submit the first set of questions when they came to class and then they worked on the second set of questions in small groups.  During the class discussion, we reviewed electrochemistry, in particular the reaction of electrodeposition of Cu2+ to Cu2O and revisited Pourbaix diagrams briefly to discuss stability of different metal oxide species.  We also discussed preferential adsorption and how this impacts crystal growth.  For a good paper on preferential absorption, see Matthew J. Siegfried and Kyoung-Shin Choi, “Electrochemical Crystallization of Cuprous Oxide with Systematic Shape Evolution,” Adv. Mater. 2004, 16, 1743-1746. (dx.doi.org/ 10.1002/adma.200400177). Schematic 1 is particularly helpful and I used it to develop the concept preferential adsorption and the relative enrgies of planes. 

Time Required: 
50 minutes
12 Jun 2015

Materials Project

Submitted by Barbara Reisner, James Madison University
Description: 

The Materials Project is part of the Materials Genome Initiative that uses high-througput computing to uncover the properties of inorganic materials.

It's possible to search for materials and their properties

It employs high-throughput computation approaches and IT to create a system that can be used to predict properties and construct phase diagrams andPourbaix diagrams.

Prerequisites: 
Corequisites: 
23 Sep 2014

Five Slides about Spectroelectrochemistry (SEC)

Submitted by Kyle Grice, DePaul University
Description: 

This "Five slides about" is meant to introduce faculty and/or students to Spectroelectrochemistry (SEC), a technique that is used in inorganic chemistry research and other areas. SEC is a powerful tool to examine species that are normally hard to synthesize and isolate due to instability and high reactivity. Papers with examples of SEC techniques are provided on the last slide. 

 

Corequisites: 
Course Level: 
Learning Goals: 

Students should be able to describe spectroelectrochemistry

Students should be able to conceptually explain how a spectroelectrochemical cell works 

Students should be able to explain the benefits of spectroelectrochemistry as compared to standard synthesis and spectroscopy approches

Implementation Notes: 

Ideally, the students would take this introduction and then go and examine specific instances of SEC in the literature. Alternatively, this can be used to help explain research papers that are being discussed that use SEC techniques. 

Students should already have an understanding of the basics of electrochemistry and spectroscopy prior to learning SEC, so this would be best suited for an upper division, special topics course in Inorganic Chemistry or Spectroscopy. There are some nice LO's on these techniques already on Ionic Viper (see related activities). 

There are some good images of the specifics of SEC cell designs on company websites or journal articles (the Organometallics article shown in the web resources is one such article). 

IR-SEC is included in the paper that is the focus of the "Dissection Catalysts for Artificial Photosynthesis" LO. 

Time Required: 
15 min
Evaluation
Evaluation Methods: 

This LO was made as a followup to the 2014 Ionic Viper workshop and has not been implemented yet. However, I plan on implementing it in a "Special Topics in Inorganic Chemisry" course in the future. 

Evaluation Results: 

None yet, will be provided upon implementation. 

4 Aug 2014

Suite of LOs on Biomimetic Modeling

Submitted by Sheila Smith, University of Michigan- Dearborn

This suite of activities can be used as a unit exploring the use of small molecule models and biophysical techniques to illuminate complicated biomolecules.  The Parent LO:  Modeling the FeB center in bacterial Nitric Oxide reductase is a short, data-filled and well-written article that is approachable with an undergraduate's level of understanding.

Course Level: 
17 Jul 2014

Introduction to Photoinduced Electron Transfer

Submitted by Robert Holbrook, Northwestern University
Description: 

This 5 slides about will introduce students to the concept of photoinduced electron transfer. These slides go over the energics of photoinduced electron transfer, which implements basic concepts of photochemistry and electrochemistry. The photoinduced electron transer properties of ris-(2,2'-bipyridine)-ruthenium(II) is used as an example. 

Prerequisites: 
Course Level: 
Learning Goals: 

Students will be introduced to photoinduced electron transfer and how to determine the driving force between an electron acceptor/donor pair. Students will be able to incororapte photochemistry and electrochemistry to inorganic complexes. Tris-(2,2'-bipyridine)-ruthenium(II) is used as an example. Students should learn the basic concept of photoinduced electron transfer and how to determine the thermodynmics for determining the driving force for PET. This maybe an interesting way to merge concepts of photochemistry and electrochemistry. The excited state of a molecule effects its reduction potentials dramatically (a 2.12 V shift in reduction potential for Ru(bpy)3). This concept is used in a wide variety of research topics from dye-sensitized solar cells to electron transfer in photosystem II.

Implementation Notes: 

These slides can be used in a lecture or a reference to introduce the concept of photoinduced electron transfer. Students must have had an introduction to basics of photochemistry and electrochemistry prior to these notes. 

Evaluation
Evaluation Methods: 

This LO has been developed for the 2014 VIPER workshop and has yet to be tested in the classroom.

17 Jul 2014

Principles and imaging applications of CEST

Submitted by Justin Massing, Northwestern University
Description: 

This five slides about chemical exchange transfer (CEST) discusses the magnetic properties of paramagnetic metal ions and their use as MR imaging agents. This includes tranditional contrast agents that affect the relaxation rate of nearby water protons and paramagnetic shift reagents suitable for CEST imaging applications. A recent redox-active cobalt complex is presented as an innovative agent for mapping redox imbalances in vivo.

Note: slides 2 and 3 are hidden. These slides present the basis of MR signal (slide 2) and relaxation mechanisms pertinent to T1 and T2 contrast agents (slide 3). This information is relevant to CEST agents since kex must be equal to or less than the frequency difference between the exhangeable protons and bulk water. Increasing the frequency difference between these two signals permits faster exchange, which may then outcompete T1 and Trelaxation mechanisms.

Corequisites: 
Course Level: 
Learning Goals: 

Following presentation of these five slides, students will be able to:

  • Discuss MR signal origin and why Gd(III)-based agents improve image contrast.
  • Identify magnetic properties relevant to relaxation and shift agents.
  • Rationalize the CEST phenomenon and why paramagnetic transition metals are suitable for developing CEST agents.
Implementation Notes: 

This LO was developed at the 2014 VIPEr Workshop: Bioinorganic Applications of Coordination Chemistry, and therefore has yet to be implemented in a classroom setting.

Evaluation
Evaluation Methods: 

This LO was developed at the 2014 VIPEr Workshop: Bioinorganic Applications of Coordination Chemistry, and therefore has yet to be graded or assessed.

16 Jul 2014

A Redox-Activated MRI Contrast Agent that Switches Between Paramagnetic and Diamagnetic States

Submitted by Vivian Ezeh, Clemson University, Department of Chemistry
Evaluation Methods: 

The success of the discussion will be evaluated by completing the take home study and the quality of the in-class discussion

Description: 

Students are asked to read an article detailing the development of a cobalt-based MRI contrast agent ("A Redox-Activated MRI Contrast Agent that Switches Between Paramagnetic and Diamagnetic States", Tsitovich, P. B.; Spernyak, J. A.;  Morrow, J. R. Angew. Chem. Int. Ed. 201352, 14247-14250,  DOI: 10.1002/anie.201306394). Before coming to class the students are asked to answer a series of questions designed to guide them through the first half of the article, and to be prepared to discuss their answers in class. During class, the answers of the questions are briefly reviewed before addressing a second set of questions in class.

Course Level: 
Corequisites: 
Learning Goals: 

1) Students explore the coordination geometry of a hexadentate N-donor ligand
2) Students pratice deriving a crystal field orbital diagram from the  magnetic properies of Co(II)/Co(III) complexes
3) Student recognize and understand the origin of the differences of 1H-NMR spectra for paramagnetic and diamagnetic complexes
4) Students understand the basic principles of how a paraCEST contrast agent works, and develop a sense of how to decide on the suitability of a metal complex as a paraCEST contrast agent based on experimental data.
5) Students become more adept at interpreting representations of data

Implementation Notes: 

This reading guide accompanies A Redox-Activated MRI Contrast Agent that Switches Between Paramagnetic and Diamagnetic States, Tsitovich, P. B.; Spernyak, J. A.;  Morrow, J. R. Angew. Chem. Int. Ed. 201352, 14247-14250,  DOI: 10.1002/anie.201306394

The LO is designed to help guide students through the reading of a scholarly article and prepare them for in-class discussion after completing the reading. 

Time Required: 
50 mins
10 Jun 2014

Protein Electrochemistry 3rd Bioinorganic Workshop

Submitted by Sheila Smith, University of Michigan- Dearborn
Description: 

This is a 90 minute talk by Fraser Armstrong of Oxford University (http://armstrong.chem.ox.ac.uk) explaining the electrochemistry of proteins immobilized on surfaces.  The talk was presented at the 3rd Bioinorganic Workshop in 2014 at Pennsylvania State University.  The talk contains an excellent basic tutorial on simple electron transfer on immobilized substrates using simple iron sulfur proteins as the primary example.  Talk continues on to more complicated subject matter including trumpet plots, electrocatalysis by enzymes focusing on the hydrogenases as an example.  The talk concludes with case studies presented on NiFe Hydrogenases, FeFe hydrogenases, and CO dehydrogenase.

Course Level: 
Corequisites: 
Learning Goals: 

The student should be able to explain the information available from electrochemistry on immobilized proteins.

Implementation Notes: 

This is an excellent presentation by the developer of many of the modern techniques for electrochemistry on immobilized proteins.  

Time Required: 
90 minute

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