General Chemistry

26 Mar 2020

Handling Air Sensitive Reagents and Working with a Schlenk Line (the COVID19 version)

Submitted by Lori Watson, Earlham College

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:

General Chemistry

Subdiscipline:

Organometallic Chemistry

Science Skills, Practices, and Resources

Course Level:

Upper Division

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.

Corequisites:

No Corequisites

Topics Covered:

Organometallic chemistry

Professional skills development

Synthesis and reactivity

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

Additional Authors:

Lisa Bell-Loncella , University of Pittsburgh at Johnstown

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.

Topics Covered:

Bonding models: Discrete molecules

Descriptive chemistry

Electronic spectroscopy

Molecular structure

Organometallic chemistry

Physical methods / analytical techniques

Synthesis and reactivity

Visualization

Prerequisites:

First Semester Inorganic Chemistry / Foundation Course in Inorganic Chemistry

Course Level:

Corequisites:

Subdiscipline:

Molecular Structure and Bonding

Organometallic Chemistry

Spectroscopy and Structural Methods

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.

Web Resources:

A very lab focused video from the Univ. of Sheffield

Video focused more on background material

Bruker Topspin for academia

MestReNova

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" 3^rd Ed. (1986 pp 108-114) 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 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. I was extremely rushed given that the governor essentially closed the state down the evening I did this, so please forgive any errors. This also includes literature searching questions.

Topics Covered:

Acid-base chemistry

Bonding models: Discrete molecules

Coordination chemistry

Electronic spectroscopy

Molecular structure

Physical methods / analytical techniques

Synthesis and reactivity

Prerequisites:

Course Level:

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 determine the species present in solutions containing various mole fractions of ethylenediamine and Ni(II).

Subdiscipline:

Coordination Chemistry

Molecular Structure and Bonding

Spectroscopy and Structural Methods

Equipment needs:

Nothing

Implementation Notes:

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

Web Resources:

Diaqua bis-ethylenediamine and tetra aquaethylenediamine nickel(II) sulfate complexes

On the Possible Existence of Tetrahedral Ni(II) Complexes

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:

General Chemistry

Subdiscipline:

Bioinorganic Chemistry

Coordination Chemistry

Electrochemistry

Nanochemistry

Organometallic Chemistry

Solid State and Materials Chemistry

Course Level:

Upper Division

Learning Goals:

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

Corequisites:

No Corequisites

Topics Covered:

Bioinorganic chemistry

Catalysis

Communication skills

Nanoscience

Organometallic chemistry

Solids & solid state chemistry

Time Required:

1 hour

21 Jan 2020

Inorganic Chemistry 2020

Submitted by Adam R. Johnson, Harvey Mudd College

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:

No Corequisites

Subdiscipline:

Coordination Chemistry

Prerequisites:

General Chemistry

Topics Covered:

Catalysis

Coordination chemistry

Course Level:

Related activities:

Mechanisms of Mn-catalyzed water oxidation reactions

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

Web Resources:

Electronic Modification of the [RuII(tpy)(bpy)(OH2)]2+ Scaffold: Effects on Catalytic Water Oxidation

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:

General Chemistry

Subdiscipline:

Bioinorganic Chemistry

Prerequisites:

General Chemistry

Topics Covered:

Bioinorganic chemistry

Course Level:

Related activities:

Characterization and Investigation of a Binuclear Manganese(III)-Peroxo Metastable Intermediate

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

Web Resources:

Catalytic Oxygen Evolution by a Bioinorganic Model of the Photosystem II Oxygen-Evolving Complex

Electronic structure of the oxygen-evolving complex in photosystem II prior to O-O bond formation

Progress Toward a Molecular Mechanism of Water Oxidation in Photosystem II

8 Oct 2019

1FLO: Post-Synthetic Modifications for Tunneling Electrical Connection to the Interior of Metal-Organic Frameworks

Submitted by daniel kissel, Lewis University

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 JACS article on synthesizing conductive MOFs. This LO introduces students to Metal-Organic Frameworks and focuses on characterization techniques and spectroscopy.

Prerequisites:

General Chemistry

Corequisites:

No Corequisites

Topics Covered:

Coordination chemistry

Electron transfer

Electronic spectroscopy

Materials chemistry

Nanoscience

Course Level:

Second year

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

Subdiscipline:

Nanochemistry

Solid State and Materials Chemistry

Related activities:

Energy Nuggets: MOF’s for CO<sub>2</sub> Sequestration

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.

Web Resources:

Tunneling Electrical Connection to the Interior of Metal-Organic Frameworks

29 Jul 2019

Introduction to Drago's ECW Acid-Base Model

Submitted by Colleen Partigianoni, Ferris State University

Description:

This LO was created to introduce Drago’s ECW model, which is an important contribution to the discussion of Lewis acid-base interactions. Unlike the qualitative Pearson’s HSAB model (Hard Soft Acid-Base model,) the quantitative ECW model can be used to correlate and predict the enthalpies of adduct formation and to obtain enthalpy changes for displacement or exchange reactions involving many Lewis acids and bases. Unlike all other acid-base models, graphical displays of the ECW model clearly show that there is no one order of acid or base strengths, and illustrate that two parameters are needed for each acid and base to provide an order of acid or base strength. The ECW model can also provide a measure of steric strain energy or pi bonding stabilization energy accompanying adduct formation, which is not possible with any other acid-base model.

This set of slides is intended to provide a basic introduction to the model and several examples of predicting energy changes using the model. It also illustrates how to construct and interpret a graphical display of the model.

It should be noted that this LO is not in the PowerPoint format, but instead is a more extensive set of notes for instructors who are not familiar with the ECW model. It could be condensed and rewritten in the more standard PowerPoint format.

There is also an ECW problem set LO that can used to supplement this LO.

Prerequisites:

General Chemistry

Subdiscipline:

Main Group Chemistry

Molecular Structure and Bonding

Topics Covered:

Acid-base chemistry

Intermolecular interactions

Course Level:

Corequisites:

Learning Goals:

After viewing the slides, students, when provided with appropriate data, should be able to:

Calculate sigma bond strength in Lewis acid-base adducts using Drago’s ECW model.

Show how to deal with any constant energy contribution (W) to the reaction of a particular acid (or base) that is independent of the base (or acid) when an adduct is formed.

Garner information regarding steric effects and pi bond stabilization energy in Lewis acid-base adducts using the ECW model.

Show using a graphic display of ECW that two parameters for each acid and each base are needed in acid-base models to determine relative strengths of donors and acceptors.

Web Resources:

The ECW Model, J. Chem. Ed. 1996

The ECW Model, Wikipedia

Evaluation

Evaluation Methods:

This LO has not been used yet and evaluation information will be posted at a later date.