General Chemistry

10 Jun 2020

A copper "Click" catalyst for the synthesis of 1,2,3-triazoles

Submitted by Chip Nataro, Lafayette College
Evaluation Methods: 

I have not used this in class yet, but anticipate updating this after the fall 2020 semester. This comes as a result of the June 9th LO party.

Description: 

This paper (Gayen, F.R.; Ali, A.A.; Bora, D.; Roy, S.; Saha, S.; Saikia, L.; Goswamee, R.L. and Saha, B. Dalton Trans2020, 49, 6578) describes the synthesis, characterization and catalytic activity of a copper complex with a ferrocene-containing Schiff base ligand. The article is relatively short but packed with information. However, many of the details that are assumed knowledge in the article make for wonderful questions some of which I hope I have captured. The LO includes electron counting using the CBC method, d-orbital splitting, Latimer diagrams and interpretation of catalytic results. There are also opportunities to discuss green chemical practices.

Corequisites: 
Prerequisites: 
Course Level: 
Learning Goals: 

A student should be able

determine the electro count and metal valence in the catalyst

use group theory to determine the number of IR active vibrations in the catalyst

discuss green chemical principles in relation to this article

interpret data from tables and draw conclusions from that data

suggest an additional catalytic experiment that could be performed

Implementation Notes: 

I like the question invoking a Latimer Diagram to get students to rationalize why the copper(I) active catalyst was not isolated. I also enjoyed sneaking in a group theory question. But my favorite quesiton is the last one in which students are asked to go beyond what it presented in the paper and suggest another catalytic reaction to perform. There are some aspects of the paper that were not covered in-depth. In particular the XPS seemed to be a rabbit hole I opted not to go down. The authors do not go into great detail on this topic and perhaps there is a question that could be included, but I opted not to. I also opted not to include anything about the bonding in ferrocene which can be found in many of my other LOs. Also on this list one might include UV-Vis spectroscopy and the computational studies.

Time Required: 
50 minutes
18 May 2020
Evaluation Methods: 

I have not yet implemented this LO. As with other literature discussions, instructors could collect the completed worksheets (by an individual student or in groups of students) for evaluation.

Evaluation Results: 

I have not yet implemented this LO so there are currently no evaluation results to share.

 

 

Description: 

This literature discussion focuses upon the Science article by Coates and Waymouth reporting the synthesis of thermoplastic elastomeric polypropylene by an unbridged zirconocene. This article was the basis for the work done for my PhD thesis in the Waymouth group. The LO was written in May 2020 in honor of Bob Waymouth's 60th birthday. See the BITeS post announcing the LO here

Course Level: 
Corequisites: 
Subdiscipline: 
Learning Goals: 

After completing this literature discussion, students will be able to:

  • describe a thermoplastic elastomer
  • describe the stereochemistry of polypropylene
  • describe the relationship between catalyst structure and polypropylene stereochemistry
  • apply covalent bond classification electron counting to a zirconocene
  • interpret data from figures and tables
  • describe the methods used by the authors to support the synthesis of isotactic-atactic stereoblock polypropylene
Implementation Notes: 

As usual, instructors may wish to mix-and-match questions to suit their learning goals and time constraints.

This article addresses a part of the ACS list of inorganic chemistry macromolecular, supramolecular and nanoscale (MSN) topics:

  • Ziegler-Natta, metallocene catalysts for olefin polymerization - impact on industrial/materials development
Time Required: 
depends upon implementation; minimum of 20-30 minutes for the literature discussion if students read and answer questions outside of class
26 Mar 2020
Evaluation Methods: 

Student learning is assessed by answers to simple scenario based questions accompanying this resouce.

Description: 

One of the features of the laboratory associated with my Inorganic chemistry course is learning to do some air sensitive chemistry using Schlenk lines (and sometimes gloveboxes).  Of course, COVID19 is keeping us out of the lab this year!  This is a collection of short web based resources (text and video) detailing begining use of a Schlenk line, something about drying and degassing solvents, and transferring liquids to a reaction flask.  It is accompanied by questions I am having students answer as part of the alternate lab I am creating in place of our usual organometallic lab experiemnt.  If you have a favorite resource that might be better/supplement the ones I found, please add to the comments!

Prerequisites: 
Corequisites: 
Course Level: 
Learning Goals: 

A student will be able to explain the basic operation of a Shlenk line and how to add reagents and solvents to a flask under inert atmosphere.

Time Required: 
2 hours, if all videos are watched and resources read.
21 Mar 2020

Ferrocene acylation - The Covid-19 Version

Submitted by Chip Nataro, Lafayette College
Description: 

This is the classic Chromatography of Ferrocene Derivatives experiment from "Synthesis and Technique in Inorganic Chemistry" 3rd Ed. (1986 pp 157-168) by R. J. Angelici. There are no significant changes from the experiment published in the book so details will not be provided. What is provided are links to some excellent videos showing the experiment and characterization data for students to work with. For the time being this will be a living document. Currently it has 1H, 13C{1H}, COSY, DEPT, HMBC, HSQC IR, UV-Vis, GC-MS and Cyclic Voltammetry raw data files for all compounds for students to work with. It also includes processed 1H, 13C{1H}, COSY, DEPT, HMBC, HSQC, IR, GC-MS and Cyclic Voltammetry data for all compounds. If anyone has any additional means of characterization they would like to include (say Mossbauer) please feel free to contact the author.

Corequisites: 
Learning Goals: 

A student should get an appreciation for what doing this lab would be like by watching videos. In addition, the student will analyze the data provided and learn about the characterization of ferrocene, acetylferrocene and 1,1'-diacetylferrocene.

Equipment needs: 

Nothing.

The NMR data comes from a Bruker instrument and can be opened with TopSpin, MestReNova and perhaps other programs.

Implementation Notes: 

Like most everyone at this time this is going to be a trial by fire.

19 Mar 2020

Job's Method - The Covid-19 Version

Submitted by Chip Nataro, Lafayette College
Evaluation Methods: 

Students are generally asked to write a full lab report including an abstract, brief introduction, experimental and results/discussion. I will likely not ask them to do that in this virtual lab. However, they will be asked to determine the value for n for the various [Ni(en)x] solutions as well as questions 1 and 2 from Angelici's book. In addition, I typically ask them to do some literature searching questions, but I am not sure if they will have access to SciFinder so I may have to bypass that or provide them the original papers I have them look at. Links to those papers are included.

Evaluation Results: 

I'll use this in a few weeks and see how it goes.

Description: 

This is the classic Job's Method experiment from "Synthesis and Technique in Inorganic Chemistry" 2nd Ed. (1977 or 1986 pp 108-114) by R. J. Angelici. There are slight changes from the experiment published in the book but they just include running solutions with ethylenediamine mole fractions of 0.67 and 0.75, so details will not be provided. What is provided are a series of pictures and videos showing the experiment being performed. Also included are the raw files of the absorbance spectra in EXCEL. It is not perfect but given the situation many of us are facing at the time this is published, it is better than nothing.Note that this lab was updated on 4/4/2020. The previous data was terrible. New solutions using a fresh bottle of ethylenediamine were prepared. The two solutions mentioned previously were also included. The data is much better. The worked up data has also been included in the instructor only files.

My apologies to my coauthors who spent way too much time looking over the original data set and trying to make sense of it. Their thoughts and insight led to this update. My sincere apologies to anyone else that scuffled over the original data.

Prerequisites: 
Corequisites: 
Course Level: 
Learning Goals: 

A student should get an appreciation for what doing this lab would be like by watching videos. In addition, the student will analyze the data provided and determine the species present in solutions containing various mole fractions of ethylenediamine and Ni(II).

Equipment needs: 

Nothing

Implementation Notes: 

Like most everyone at this time this is going to be a trial by fire.

19 Mar 2020

Online Seminar Talks

Submitted by Amanda Reig, Ursinus College
Evaluation Methods: 

Student summaries are simply graded as complete/incomplete and are checked to see that they did in fact watch the video. If student summaries are felt to be lacking substance or incomplete, we will indicate areas they can improve on future summary reports.

Description: 

In an attempt to find a substitute for our chemistry seminar program, I have found a number of YouTube videos of chemists giving seminar lectures, mostly between 2017-2020. The topics span a range of chemistry disciplines, and are all around 1 hour in length (typical seminar length).  I have not watched them, so I cannot vouch for video quality. Feel free to add additional links in the comments below if you know of or find any great talks.

We will ask students to select and watch a certain number of lectures from the list and then write and submit a one-page summary of the talk.

Prerequisites: 
Course Level: 
Learning Goals: 

A student should be able to summarize the key points of a lecture presented by a seminar speaker.

Corequisites: 
Time Required: 
1 hour
17 Jan 2020

Formal oxidation states in Ru-catalyzed water oxidation

Submitted by Margaret Scheuermann, Western Washington University
Evaluation Methods: 

I did not grade this activity.

Evaluation Results: 

Three students out of 14 explicitly mentioned that this activity was helpful on the free response section of the course evaluations.

Description: 

This LO is an in-class assignment to prepare students for literature readings involving catalytic cycles in which multiple protons and electrons are transferred. Students practice assigning oxidation states to complexes with aquo, oxo, superoxo, and hydroperoxo ligands then use this information to analyze a proposed water oxidation mechanism from the literature.

Students are asked to add in the substrates and products entering and leaving the catalytic cycle. While this is, at its heart, a stoichiometry excercise, it helps calibrate students for the level of attention to detail needed to effectively engage with reading about multi-electron catalytic mechanisms.

Learning Goals: 

After completing this activity:

A student should be able to assign formal oxidation states to monometallic complexes with aquo, oxo, hyrdoperoxo, and superoxo ligands

A student should be able to apply their knowledge of formal oxidation states to the analysis of a proposed mechanism of a catalytic water oxidation reaction

Corequisites: 
Subdiscipline: 
Prerequisites: 
Implementation Notes: 

I used this activity during a lab lecture before an inorganic laboratory experiment in which students would be preparing and testing the Ru-based OEC mimic. 

I began the class period with a brief review of L/X type ligands and formal oxidation states. 

Students then worked in groups to complete this activity. 

 

Other implementation options:

While I used this activity as part of a lab lecture it could also be used in a lecture setting or as part of a problem set.

It could also be modified for use as an equation balancing excercise in a majors or honors general chemistry course.

Time Required: 
10-20 minutes
18 Oct 2019

Mechanisms of Mn-catalyzed water oxidation reactions

Submitted by Margaret Scheuermann, Western Washington University
Evaluation Methods: 

I did not grade this activity. 

Evaluation Results: 

Three students out of 14 explicitly mentioned that this activity was helpful on the free response section of the course evaluations.

 

Description: 

This LO is an in-class assignment to prepare students for literature readings involving catalytic cycles in which multiple protons and electrons are transferred. Two catalytic mechanisms, a proposed OEC mechanism and the proposed mechanism of a biomimetic OEC complexes are included. The intermediates are drawn including all charges and oxidation states, details which are sometimes omitted in the primary literature but can be helpful to students who are not accustomed to looking at multistep catalytic cycles. Students are then asked to add in the substrates and products entering and leaving the catalytic cycle. While this is, at its heart, a stoichiometry excercise, it helps calibrate students for the level of attention to detail needed to effectively engage with reading about bioinorganic catalytic mechanisms.

Learning Goals: 

After completing this activity:

A student will be able to follow along with each step in  proposed water oxidation mechanims in the literature.

A student will be able to apply their knowledge of stoichiomety to complex catalytic cycles involving electron transfer.

A student will be able to analyze and compare the details of catalytic cycles.

Corequisites: 
Subdiscipline: 
Prerequisites: 
Implementation Notes: 

I used this activity during a lab lecture before an inorganic laboratory experiment in which students would be preparing and testing an OEC mimic. The procedure we used was roughly based on a published procedure (J. Chem Ed. 2005, 82, 791) linked in web resources. 

I began the class period with a brief introduction to the chemistry of photosynthesis and where water oxidation and PSII fit in the broader picture. I then introduced the mimic that students would be preparing and the chemistry of the Oxone (R) triple salt. 

Students then worked in groups to complete this activity and discuss their structural and mechanistic observations. After the activity they were encouraged to read the papers referenced in the activity and to think about the evidence that supports the proposed mechanism.

 

Other implementation options:

While I used this activity as part of a lab lecture it could also be used to stimulate a discussion comparing structure/mechanism of biological and biomimetic systems in a lecture setting without the accompaning laboratory work.

This could also be modified for use as an equation balancing excercise in a majors or honors general chemistry course.

Time Required: 
10-20 minutes
8 Oct 2019
Evaluation Methods: 

assessment of students will be preformed by grading their answers to the questions in the activity.

Description: 

This is a 1 Figure lit discussion (1FLO) based on a Figure from a 2015 JACarticle on synthesizing conductive MOFs. This LO introduces students to Metal-Organic Frameworks and focuses on characterization techniques and spectroscopy. 

Prerequisites: 
Corequisites: 
Course Level: 
Learning Goals: 

As a result of completing this activity, students will be able to...

  • define what metal-organic Frameworks and Post-synthetic Modifications are
  • understand MOF terminology and notation
  • discover how mass transport and electron mobility effect conductivity
  • calculate energies of electronic transitions in electron volts
  • make connections betweeen diagrams and material sturctures
  • compare optical and microscopy techniques
  • discover the concept of photocurrect and how it could be used in different applications
Implementation Notes: 

Students should be able to complete the activity without any prior knowledge of MOFs, although some introduction to MOFs and UV-vis absorption spectroscopy would be nice.

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