VIPEr

First Semester Inorganic Chemistry / Foundation Course in Inorganic Chemistry

Prerequisites:

General Chemistry

Corequisites:

Subdiscipline:

Polypropylene Stereochemistry and Identification by 13C NMR Spectroscopy

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

Topics Covered:

Catalysis

Chemical literature

Related activities:

Chapter 19--Stanley Organometaliics

Chapter 21--Stanley Organometallics

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

Web Resources:

Link to Science article

6 Apr 2020

Schlenk Line Survival guide

Submitted by Adam R. Johnson, Harvey Mudd College

Evaluation Methods:

This is really more of a resource. I have not used it but I have a link to it in my reserach SOP folder. I think it would be good to show the students a general resource before teaching them the specifics of a local line.

Description:

I feel like I've shared this resource before but I couldn't find it so maybe it will stick this time :)

This is a good resource created by "Dr. Andryj Borys, a main-group chemist, phosphorus fanatic and Schlenk line enthusiast." He is currently a postdoc in Canada, headed back to Europe in 2020 (supposedly..)

this resource describes the use of a Schlenk line in quite a bit of detail, with a variety of standard applications (cannula transfer, sealing NMR tubes).

Topics Covered:

Synthesis and reactivity

Prerequisites:

Corequisites:

Course Level:

Subdiscipline:

Coordination Chemistry

f-block Chemistry

Science Skills, Practices, and Resources

Learning Goals:

A student can use this resource to learn general features of a Schlenk line.

Related activities:

Virtual Schlenk Line

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

Web Resources:

Schlenk Line Survival Guide

6 Apr 2020

Migratory Insertion Guided inquiry

Submitted by Adam R. Johnson, Harvey Mudd College

Evaluation Methods:

I look to see if students are able to

1) determine the correct number of IR stretches for the compounds,

2) calculate the labeled IR stretches from the unlabeled ones,

3) correctly predict the product distributions expected for the 3 mechanistic pathways

4) understand/explain the importance of experiment 2, negative evidence, and microscopic reversibility

Evaluation Results:

Awaiting assessment data at time of submission; will add ASAP.

based on 3 complete submissions (43% response rate, due to COVID)

students generally had no problems with questions 1 and 2, and were able to determine the number/symmetry of IR stretches using group theory, and to predict a vibrational frequency from a areduced mass calculation.

question 3 gave them a lot of trouble. I would normally do this as an in-class exercise and be able to talk them thorugh problems. students were able to draw some of the correct products for the various mechanisms but did not understand the fact that there would be a statistical distribution of products based on the 13C label. However, I spoke with all 3 students and they said that after priming their brains with the exercise, the reading in the textbook made a lot of sense and they understood what they had missed. Perfect!

Students did not generally understand the concept of negative evidence as hoped.

For future years, if I were unable to do this exercise in class, I would want to provide more guidance to get students to think about product distribution. However, if done in class, I think that watching them struggle a bit before helping them over the hurdle would be good.

Description:

The migratory insertion reaction is one of the "four" main reactions in organometallic chemistry. It involves the formation of an acyl group by insertion of a CO molecule into a metal alkyl bond. The reaction is sometimes called the carbonyl insertion reaction because the product appears to be a result of direct insertion of the CO into the metal alkyl, but that name implies a mechanistic pathway that may not be in operation.

The reaction of methyl pentacarbonyl manganese(I), MeMn(CO)₅, was studied extensively by Calderazzo in the mid 1960s. The use of C13 labeled CO and IR spectroscopy allowed for the identification of the mechanism for the reaction among the likely possibilities of direct insertion, alkyl migration, or carbonyl migration. This guided inquiry exercise presents some of the data from the Calderazzo paper and has students interpret it to determine the mechanism of the reaction in this system.

It should be noted that there are examples of all three mechanisms operating in different chemical systems, so this exercise is specific to the manganese substrate, though it is usually more generally applied.

Learning Goals:

Students will interpret and analyze IR data of metal carbonyls

Students will calculate IR bands for 13C labeled peaks in the IR

Students will predict product distributions for the three likely mechanisms (direct insertion, carbonyl migration, alkyl migration).

Students will compare expected and observed product distributions and identify the mechanism operating

Students will discover and discuss the concept of "negative evidence."

Equipment needs:

none

Topics Covered:

Reaction mechanisms

Prerequisites:

Corequisites:

Subdiscipline:

Course Level:

Isotopic labeling and reduced mass calculations for IR spectroscopy

Related activities:

Implementation Notes:

In my course, we usually cover isotopic labeling and its application to IR spectroscopy. We also use group theoretical methods to predict and assign M-CO stretches the correct symmetry labels and whether they are IR active or not. These two factors could be removed from the guided inquiry and presented as additional data to the students if you don't cover these topics. The rest of the activity is self contained. Access to the paper is not required, as the IR bands are in the document but a reference is provided.

Time Required:

30-50 minutes

Web Resources:

JOMC 1967, 10(1), 101-104

21 Mar 2020

chromium and molybdenum arene complexes (COVID-19 version)

Submitted by Adam R. Johnson, Harvey Mudd College

Evaluation Methods:

i have no idea.... yet! (growth mindset!)

Evaluation Results:

I will report this later this spring.

Description:

The synthesis of (arene)Cr(CO)₃ and (arene)Mo(CO)₃ complexes are fairly standard experiments in the organometallic curriculum. I present here some student data and experimental descriptions of real procedures carried out at Harvey Mudd College over the previous two to three years. The word document has the answers in it so it is posted under "faculty resources" but the raw data (pdf or png form) is presented for those who need data to support their distance learning classrooms in the Spring of 2020. I also include an input file for Mo(benzene)(CO)3 should you desire to use WebMO or Gaussian to carry out some calculations.

there was a minor mistake in the reported integrations for one of the complexes in the original faculty only file; it has been fixed in the v2 version.

Course Level:

Prerequisites:

Corequisites:

Subdiscipline:

Learning Goals:

Students will interpret provided data to write their own experimental sections for molecules they were unable to prepare in the lab. The guided inquiry part allows students to use data to predict the outcome of a chemical reaction.

Topics Covered:

Nomenclature

Job's Method - The Covid-19 Version

Equipment needs:

be able to view PDF/PNG files

Related activities:

Ferrocene acylation - The Covid-19 Version

Manganese Carbonyl experiment

Manganese carbonyl calculation addition

Implementation Notes:

I have not used this yet but will be using it spring 2020.

Time Required:

unknown

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:

Descriptive chemistry

Electronic spectroscopy

First Semester Inorganic Chemistry / Foundation Course in Inorganic Chemistry

Synthesis and reactivity

Visualization

Prerequisites:

Course Level:

Corequisites:

Subdiscipline:

Molecular Structure and Bonding

A very lab focused video from the Univ. of Sheffield

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:

Video focused more on background material

Bruker Topspin for academia

MestReNova

21 Jan 2020

Inorganic Chemistry 2020

Submitted by Adam R. Johnson, Harvey Mudd College

9 Oct 2019

Fourier Transform IR Spectroscopy of Tetrahedral Borate Ions

Submitted by Zachary Tonzetich, University of Texas at San Antonio

Evaluation Methods:

The students perpare laboratory reports displaying their data in proper format with each peak labeled. The report must also contain answers to all of the quetions posed in the manual. Student performance and learning is assessed by the qualtity of their written reports and by a separate quiz covering aspects of vibrational spectroscopy. Teaching assistans also ensure that students' data acquisition is performed in a satisfactory manner during the laboratory period.

Evaluation Results:

Students typically have great difficulty connecting the idea of normal modes, their symmetries, and why we observe IR peaks. They approach IR spectroscopy in much the same way they do NMR spectroscopy (i.e. methane shows four equivalent C-H bonds so I expect one C-H stretching motion) leading to serious misconceptions. This laboratory was designed in part to dispell these misconceptions. Question 1 addresses this issue most directly and many of the class answer incorrectly.

The questions in the laboratory involving harmonic oscialltor analysis are generally more straightforward for students as they just need to use the correct equations. Most of the class answers these correctly.

Likewise, students generally understand that vibrational frequencies are inversely proportional to the mass of the atoms involved in the vibration and are there able to make connections between the observed spectra of BH₄^-, BD₄^- and BF₄^-.

Aspects of functional group analysis are more familiar to students and they generally have little trouble assigning the spectrum of tetraphenylborate.

Description:

This experiment was developed for an upper division Instrumental Analysis course to give students additional experience with infrared (IR) spectroscopy beyond the routine functional group identification encountered in undergraduate Organic Chemistry courses. It shares some aspects with the analysis of gas phase rovibrational spectra typically performed in Physical Chemistry courses, but places a greater emphasis on more practical considerations including data acquisition (using ATR) and interpretation. The molecular ions used in the experiment also demonstrate tetrahedral symmmetry which allows for topics in Group Theory to be exploited.

The experiment has students record the spectra of several tetrahedral borate ions including the isotopomers NaBH₄ and NaBD₄. The students then analyze their data in the context of the symmetry of normal modes, the harmonic osciallator model, comparisons with Raman spectra, and functional group composition. Post lab questions guide students through each of the topics and ask them to make quantative and qualitative predictions based on their data and theoretical models of molecular vibration.

Course Level:

First Semester Inorganic Chemistry / Foundation Course in Inorganic Chemistry

Prerequisites:

Physical Chemistry: Quantum Mechanics

Corequisites:

Subdiscipline:

Molecular Structure and Bonding

Learning Goals:

-Students should be able to understand the relationship between molecular structure, normal modes, and peaks in the IR spectrum. This is a major misconception with students as they tend to believe that the presence of four B-H bonds in the borohydride ion will neccessary mean that four peaks (or one since they are equivalent) will be observed by IR. Unlike NMR spectroscopy, there is no 1:1 correspondence between the number of equivalent bonds and the number of peaks observed in the spectrum.

-Students should also be able to apply their knowledge of theoretical models (quantum harmonic oscillator) to quantitaively intrepret IR spectra and predict the energy of transitions that cannot be observed due to instrumental limitations.

-Students should be able to understand at a qualitative level how the masses of atoms affect the energy of molecular vibrations.

Topics Covered:

Isotopic labeling and reduced mass calculations for IR spectroscopy

Symmetry

Equipment needs:

The only required piece of equipment beyond the chemicals is an infrared spectrophotometer. At our institution we use an ATR element to acquire the data, but KBr pellets or nujol mulls should work equally well. All chemicals were purchased from Sigma-Aldrich and are of reasonable price.

Related activities:

CompChem 05: Infrared, Thermochemistry, UV-Vis, and NMR

Vibrational Modes and IR Spectra using Character Tables

Good resource for Teaching IR with Symmetry Elements

Synthesis and Molecular Modeling of Sodium Tetrathionate

Implementation Notes:

See attached file with more details. The data acquisition is very straightforward if ATR sampling is employed. Students need only use the instrument for about 15 - 20 minutes to record all four samples.

Time Required:

30 minutes to 2 hr depending upon the number of students.

25 Jul 2019

1FLO: One Figure Learning Objects

Submitted by Chip Nataro, Lafayette College

Course Level:

First year

Second year

Molecular Structure and Bonding

Subdiscipline:

Coordination Chemistry

Electrochemistry

f-block Chemistry

Topics Covered:

Acid-base chemistry

Catalysis

Chemical literature

Coordination chemistry

Electron transfer

Electronic spectroscopy

Electronic structure

f-block chemistry

Kinetics

Symmetry

Synthesis and reactivity

Corequisites:

First Semester Inorganic Chemistry / Foundation Course in Inorganic Chemistry

Prerequisites:

General Chemistry

9 Jun 2019

Comprehensive literature reading assignment on platinum-based anticancer agents

Submitted by Todsapon Thananatthanachon, University of Evansville

Description:

Students read two review articles and one research article on platinum-based cancer therapeutic agents. These articles compresentively discuss various aspects of these drug agents such as discovery, synthesis, mode of function. Students read the articles and use the knowledge on coordination chemistry (structure, reactivity, bonding, etc.) to explain the information included in the articles.

References:

1) Mudiyanselage,R.; Rajapakse, G.; Dunuweera, S. P. Discovery, Chemistry, Anticancer Action and Targeting of Cisplatin. International Journal of Clinical Oncology and Cancer Research, 2017, 2, 65-74.

2) Takahara, P.; Rosenzweig, A. C.; Frederick, C. A.; Lippard, S. J. Crystal structure of double-stranded DNA containing the major adduct of the anticancer drug cisplatin. Nature 1995, 377, 649-652.

3) Cai, L.; Yu, C.; Ba, L.; Liu, Q.; Qian, Y.; Yang, B.; Gao, C. Anticancer platinum-based complexes with non-classical structures. Applied Organometallic Chemistry 2018, 32, e4228.

Prerequisites:

Course Level:

Topics Covered:

Bioinorganic chemistry

Coordination chemistry

Reaction mechanisms

Corequisites: