Synthesis and reactivity

30 Jun 2016
Evaluation Methods: 

Informally faculty will walk around the room evaluate and assist with the challenges students face as they go through the activity.

Every group of students will submit one set of answers that will be graded for accuracy. Some questions are lower-level and intended to help students identify key ideas and relevant data from the paper. These questions could be worth fewer points while more complex quesitons could be worth more points.

We envision that faculty members will not have a challenging grading load since the discussion will happen during class and most answers will generated during class discussion.

Evaluation Results: 

We have not yet tested this activity in the class.

Description: 

This literature activity is designed to introduce students to the concept of outer-sphere hydroboration catalytic reactions. It can be used after hydrogenation and hydroboration reactions have been introduced in class (typically covered in organic chemistry). Additionally, this activity allows students to apply their understanding of redox chemistry, acid base chemistry, and physical techniques to characterize products and elucidate reactions mechanisms.

The LO is built around a paper by the Szymczak group (JACS, 2015, 137, 12808-12814) where they describe the role of ligand design and its ability to be modified via acid-base reactions to change the reactivity of a hydroboration catalyst.

The LO has a modular design and can be taught in its entirety or in pieces. It also contains links to related LOs that can serve to reinforce, or introduce, concepts covered in this activity.

Corequisites: 
Prerequisites: 
Learning Goals: 

After completing this assignment students will be able to…

Lower-order thinking

  • Recognize the key features of a hydroboration outer-sphere catalytic mechanism
  • Define turnover frequency and explain how turnover frequency represents catalyst effectiveness
  • Label the nucleophile and electrophile in different hydroboration species
  • Explain the key features of a hydroboration outer-sphere catalytic mechanism
  • Describe how redox-potential affects the nucleophilicity of metal-hydride complexes
  • Describe how spectroscopy is used to help elucidate reaction mechanisms
  • Summarize key points from an article in the primary literature

Higher-order thinking

  • Elucidate how (de)protonation of the catalysts modulates their nucleophilicity
  • Write and revise a hypothesis
  • Compare and contrast hydroboration of nitriles using NaBH4 (stoichiometric) and an outer-sphere hydroboration catalyst
  • Generalize how (de)protonation of metal complexes modulates their nucleophilicity
  • Infer how the secondary coordination of metal complexes can alter reactivity
  • Optional: Apply symmetry rules to assign the point group of compounds
  • Optional: Connect spectroscopic experimental evidence to the symmetry of compounds
Subdiscipline: 
Implementation Notes: 

Note to the instrucutor: This activity has not been tried in class before. We look forward to hearing input from anyone who implements this LO.

Before reading the article students will generate their initial hypothesis as an exercise to test their initial understanding purely on theoretical background from the course (2016 Szymczak LitDiscussion-Handout). Students will then read the paper and during the next class period they will work in groups of 2 or 3 students to answer the questions about the paper (2016 Szymczak LitDiscussion).

This activity is intended to be modular; each section is divided according to themes. If an instructor wants to do the whole activity it is possible but each module can be taught independently. The hypothesis generation and revision prompts are also something that instructors might choose to leave out depending on the needs of the class.

The faculty member will alternate between periods of monitoring the students’ progress and having the class report out their findings.

Time Required: 
One class period
29 Jun 2016

Ligand Design for Selectivity and Complex Stability

Submitted by daniel kissel, Lewis University
Description: 

This is an overview of some important principles of ligand design. Topics covered include HSAB theory, the chelate effect, the chelate ring size effect, the macrocyclic effect, the cryptate effect, and steric focus in ligand design.

Corequisites: 
Course Level: 
Prerequisites: 
Subdiscipline: 
Learning Goals: 

Students will be able to:

  • identify how to best design a ligand to achieve a specific function
  • evaluate how certain design characteristics can impact metal ion selectivity and complex stability
  • infer what kinds of ligand design characteristic would be important in specific inorganic complexes
  • observe the chelate effect
  • observe the chelate ring effect
  • observe enthalpic contributions in ligand systems
  • observe the macrocyclic effect
  • observe the cryptate effect
  • observe the concept of steric focus in ligand design
Implementation Notes: 

These are some general rules for ligand design that are the result of my own personal research as well as topics I learned from my graduate advisor. This only serves as a general guideline and it should be noted that there are some exceptions to these rules (as is the case in most things we do in inorganic chemistry).

Time Required: 
15-20 minutes
Evaluation
Evaluation Methods: 

I will evaluate how well the students understand the concepts presented here by using class discussion and testing students over the concepts on an exam question about ligand design

Evaluation Results: 

This LO was created at the IONiC VIPEr conference 2016, and has not been implemented or evaluated yet, but will be in the upcoming spring 2017 semester

27 Jun 2016

A Guided-Inquiry Approach to Building a Catalytic Cycle

Submitted by Murielle Watzky, University of Northern Colorado
Description: 

This activity introduces students to fundamental types of organometallic reactions, and directs them to examine how each of these reactions affects the total electron count for the organometallic complex and the oxidation state of the central metal.  Students are then directed to use these reactions to build a sequence of steps for a catalytic cycle.

Learning Goals: 

Upon completion of this activity, students will be able to…

-       discuss fundamental organometallic reactions.

-       determine how fundamental organometallic reactions affect the total electron count in an organometallic complex and the oxidation state of the central metal.

-       apply their knowledge of fundamental organometallic reactions to put together a catalytic cycle.

-       understand the cyclic nature of catalysis.

Subdiscipline: 
Corequisites: 
Course Level: 
Implementation Notes: 

This activity can be used as an introduction to fundamental organometallic reactions and/or catalytic cycles. Students should work in small groups of 3-4.  Student must already be able to count electrons in an organometallic complex.

27 Jun 2016

Online Homework for a Foundations of Inorganic Chemistry Course

Submitted by Sabrina G. Sobel, Hofstra University
Evaluation Methods: 

Students are graded on a sliding scale based on the number of attempts on each question. An overall grade is assigned at the end of the semester, adjusted to the number of points allotted for the homework in the syllabus. 

Evaluation Results: 

Student performance on the overall homework assignments for the semester includes questions assigned on General Chemistry topics that are part of this class syllabus. 

 201420152016
Number404741
Average89%80%83%
S.D.15%19%23%

In addition to gethering data on overall  performance, I and my student assistants, Loren Wolfin and Marissa Strumolo, have completed a statistical study to assess performance on individual questions, and to identify problem questions that need to be edited. We identified two separate issues: incorrect/poorly worded questions, and assignment of level of difficulty. Five problematic questions were identified and edited. The level of difficulty was reassigned for eight questions rated as medium (level 2); six were reassigned as difficult (level 3), and two were reassigned as easy (level 1). I look forward to assessing student performance in Spring 2017 in light of these improvements. Please feel free to implement this Sapling homework in your class, and help in the improvement/evolution of this database.

Description: 

The Committee on Professional Training (CPT) has restructured accreditation of Chemistry-related degrees, removing the old model of one year each of General, Analytical, Organic, and Physical Chemistry plus other relevant advanced classes as designed by the individual department. The new model (2008) requires one semester each in the five Foundation areas: Analytical, Inorganic, Organic, Biochemistry and Physical Chemistry, leaving General Chemistry as an option, with the development of advanced classes up to the individual departments. This has caused an upheaval in the treatment of Inorganic Chemistry, elevating it to be on equal footing with the other, more ‘traditional’ subdisciplines which has meant the decoupling of General Chemistry from introduction to Inorganic Chemistry. No commercial online homework system includes sets for either Foundations or Advanced Inorganic Chemistry topics. Sapling online homework (www.saplinglearning.com) has been open to professor authors of homework problems; they have a limited database of advanced inorganic chemistry problems produced by a generous and industrious faculty person. I have developed a homework set for a semester­-long freshman/sophomore level Inorganic Chemistry course aligned to the textbook Descriptive Inorganic Chemistry by Rayner-Canham and Overton (ISBN 1-4641-2560-0, www.whfreeman.com/descriptive6e ), and have test run it three times. Question development, analysis of student performance and troubleshooting in addition to topic choices, are critical to this process, especially in light of new information about what topics are taught in such a course (Great Expectations: Using an Analysis of Current Practices To Propose a Framework for the Undergraduate Inorganic Curriculum: http://pubs.acs.org/doi/full/10.1021/acs.inorgchem.5b01320 ).This is an ongoing process, and I am working to improve the database all the time.

Prerequisites: 
Corequisites: 
Course Level: 
Learning Goals: 

1.      Increase understanding in these topic areas:

a.      Acid-base chemistry and solvent systems

b.      Bonding models of inorganic molecules and complexes

c.      Bonding models in extended systems (solids)

d.      Descriptive chemistry and Periodic Trends

e.      Electronic structure of inorganic molecules, complexes and solids

f.       Extended structures: unit cells and other solid-state structural features

g.      Molecular structure and shape of inorganic molecules

h.      Inorganic Complexes nomenclature, bonding and shapes

i.       Redox chemistry and application to inorganic systems

j.       Thermodynamics as applied to inorganic solids and inorganic systems

2.      Practice using knowledge in these topic areas:

a.      Acid-base chemistry and solvent systems

b.      Bonding models of inorganic molecules and complexes

c.      Bonding models in extended systems (solids)

d.      Descriptive chemistry and Periodic Trends

e.      Electronic structure of inorganic molecules, complexes and solids

f.       Extended structures: unit cells and other solid-state structural features

g.      Molecular structure and shape of inorganic molecules

h.      Inorganic Complexes nomenclature, bonding and shapes

i.       Redox chemistry and application to inorganic systems

j.       Thermodynamics as applied to inorganic solids and inorganic systems

Implementation Notes: 

The database of homework questions is available through Sapling Learning. They can be implemented as an online homework set for a class. Students need to buy access to the Sapling online homework for the duration of the class, typically $45.

Time Required: 
variable
10 Jun 2016

George Stanley Organometallics

Submitted by Adam R. Johnson, Harvey Mudd College

This is an LO for the collection of organometallics LOs by George Stanley. Adam Johnson is curating the material that was written by George.

For many years, George hosted his organometallics lecture notes, powerpoint slides, and handouts, on his personal website at LSU. He always wanted that material available to the public. Recently, they moved to a CMS and that material is no longer available. Adam is working with George to get the 2016-2017 version of his materials up on VIPEr for everyone to use.

The lecture notes are freely available to all.

Subdiscipline: 
Prerequisites: 
Corequisites: 
Course Level: 
23 May 2016

Ligand effects in titration calorimetry from the Angelici lab

Submitted by Chip Nataro, Lafayette College
Evaluation Methods: 

This LO was first presented during the 2016 Workshop at the University of Michigan. After working on the LO for a bit, the particpants were tasked with developing a rubric for this LO. This rubric has now been posted with the LO as a faculty only file. I thanks the participants for their contribution to this LO and their suggestions.

Description: 

This literature discussion focuses on a paper from the Angelici lab that examines the heat of protonation of [CpʹIr(PR3)(CO)] compounds. The compounds presented in the paper provide good introductory examples for electron counting in organometallic compounds. The single carbonyl ligand in these compounds provide an excellent probe to monitor the electron richness at the metal center which is impacted by the electron donor ability of the ligands. The technique of titration calorimetry presented in this paper is likely new to the students, but it is just a combination of two techniques they likely learned about in general chemistry. This LO was developed as part of the 2016 workshop on Organometallic Chemistry. 

Corequisites: 
Course Level: 
Learning Goals: 

A student should be able to

  1. apply the CBC method for electron counting to the Ir complexes in this paper
  2. explain the titration calorimetry experiment and describe what it measures
  3. describe the bonding in metal carbonyl compounds and explain how the electron richness at the metal center impacts the bonding in these compounds
  4. describe the electron donor ability difference of Cp* as compared to Cp
  5. explain the differences in electron donor ability of phosphine ligands
  6. relate the basicity of the metal complex to the electron donor ability of the ligands

A more advanced student may

  1. question the chemical shift of a M-H in the 1H NMR spectrum
  2. question the chemical shifts in the 31P NMR spectrum if they only have experience with 1H NMR
  3. connect the reactions performed in this paper to oxidative addition, in particular if they note the change in the valence of the Ir
  4. read the nucleophilicity studies in more detail
Implementation Notes: 

I use the CBC method of electron counting, so that is how the electron counting is presented. Certainly you can modify this to meet your electron counting needs.

The paper presents both the heat of protonation study and the reaction of the Ir compounds with MeI (referred to as nucleophilicity). The general trends in both studies are the same, but the nucleophilicity studies are a bit more complex to read. There is plenty to learn from this paper without worrying about the nucleophilicity studies, so the focus of the LO is on the heat of protonation studies. Additional questions could certainly be developed to include the nucleophilicity studies.

In order to guide the students, I would provide them with a pdf version of the paper with the following comments.

Page 1322 Experimental Section highlighted in yellow - There are lots of great details in the Experimental Section but most of them would only be useful if you are actually repeating this work. For our purposes you can skip most of these fine details.

The sub-sections highlighted in green provide general details about the experiments that were performed and should be read.

Numbers highlighted in blue may prove useful during our discussion of this paper.

Page 1322 Synthesis of CpIr(CO)(PR3) Complexes highlighted in green.

Beginning on page 1322 and ending on page 1324 all of the nCO values are highlighted in blue.

Page 1325 section Calorimetric Studies of Reaction 1 is highlighted in green.

Page 1326 Results is highlighted in yellow - While all of the results section contains interesting details, the sections highlighted in green will be most useful for our discussion.

Page 1327 Characterization of Products in Reactions 1 and 2 the first paragraph is highlighted in green.

Page 1327 Calorimetric Studies section is highlighted in green.

Page 1328 Discussion is highlighted in yellow - While all of this section is an interesting read, the subsection headings highlighted in green will be of the most use for our discussion.

Page 1328 Basicities of CpIr(CO)(PR3) Complexes 1-11 subsection is highlighted in green.

Page 1328 Basicities of Cp*Ir(CO)(PR3) Complexes 12-16 subsection is highlighted in green.

Page 1329 Effects of Cp* and Cp on Metal Basicity (DHHM) in CpʹIr(CO)(PR3) subsection is highlighted in green.

Time Required: 
~50 minutes
23 Mar 2016

Nanomaterials Chemistry

Submitted by Anne Bentley, Lewis & Clark College

This list includes a number of LOs to help in teaching nanomaterials subjects; however, it is not exhaustive.

Updated June 2018.

Prerequisites: 
Corequisites: 
11 Jan 2016
Evaluation Methods: 

When implemented during the 2016-2017 school year a formal lab report will be required. However, other suitable methods would include, but are not limited to an oral presentation or a lab memo.

Evaluation Results: 

The experiment described herein will be piloted during the 2016-2017 school year. However, all complexes have been prepared by undergraduate students/researchers at all levels during the completion of the original project. 

Description: 

In this experiment, students will synthesize and characterize a series of Ru(II) p-cymene piano-stool complexes. Each complex will contain p-cymene as the "seat" and two chloride donors in addition to a phosphine or phosphite with varying amounts of fluorine, which together serve as the "stands". There are a total of four phosphine ligands and three phosphites, which include triphenylphosphine and trimethylphosphite that do not contain any fluorine. This experiment combines complex synthesis, characterization, data analysis and data sharing.

Course Level: 
Learning Goals: 

A student should be able to:

  1. Prepare a series of Ru(II) phosphine and phosphite complexes
  2. Characterize the complexes by multi-nuclear NMR spectroscopy
  3. Characterize the complexes by UV-vis spectroscopy
  4. Analyze structural data in Mercury
  5. Use physical characterization data to formulate trends
  6. Use data tables when appropriate
  7. Express conclusions
  8. Write a full ACS journal style lab report 
Corequisites: 
Equipment needs: 

Standard laboratory equipment/glassware

Rotary evaporator

FT-NMR with multinuclear capablity 

UV-vis spectrophotometer

Implementation Notes: 

This experiment will be piloted during the 2016-2017 school year. If others in the VIPEr community try this experiment please post your comments and/or consider filling out the feedback file attached and sending to john-lee@utc.edu

Students will synthesize and characterize one compound each, and should share spectral and other characterization data in order to perform a complete study for their report. All complexes are air-stable and can be prepared without the need for anaerobic techniques. Students should form a hypothesis on the donor ability of the ligand and then use their characterization data along with the structure of the phosphine or phosphite to support and/or refine their original predictions.

Time Required: 
Two to Three 3-hour lab periods
28 Sep 2015

Working with Catalytic Cycles

Submitted by Matt Whited, Carleton College
Evaluation Methods: 

Informal evaluation during group work and during group presentations

Evaluation Results: 

I most recently used this LO in the early weeks of a dedicated "Organometallic Chemistry" course after a fairly brief introduction to reaction mechanisms, as a way of transitioning to catalysis.  The students performed well on activity, easily completing the "fill-in-the-blank" problems, though they struggled a little more on the free response questions.  In particular, some groups needed help in assigning the role of HI in the Monsanto process.

Overall, this activity did a much better job than lectures I have used in past years to introduce catalysis.  Students identified key points where catalysis can be interrupted and factors to consider when thinking about overall rates and side products.

Description: 

Students work in groups to identify relevant steps and intermediates in 3 catalytic cycles, all the while considering bonding (and electron counting) factors.  Following assignment of these steps and intermediate species, the students consider several questions related to catalysis more broadly, particularly the role of each reagent, how to speed up or slow down specific steps, and the importance of regiospecificity in certain steps.

Learning Goals: 
  • Students will be able to apply knowledge of fundamental organometallic reaction classes to put together a catalytic cycle
  • Students will be able to consider the interplay of different steps and chemical species during catalysis, including structural factors allowing certain steps to occur
  • Students will be able to explain the role of accessible species not directly on the catalytic cycle and how these relate to the desired catalysis
Corequisites: 
Course Level: 
Subdiscipline: 
Implementation Notes: 

Students worked in groups of 3-4, allowing me to circulate and help groups as they came upon problems.  After allowing sufficient time for their work (maybe 15 minutes), I had groups present their answers for discussion by the class.

Time Required: 
30 minutes
16 Sep 2015

Iron Cross-Coupling Catalysis

Submitted by Laurel Goj Habgood, Rollins College
Evaluation Methods: 

Our proposed evaluation method is a written report in the style of an Inorganic Chemistry communication.  Instructors may choose an alternative method, such as an oral presentation, that is more appropriate for their class.

Evaluation Results: 

This experiment will be piloted during the 2015-2016 school year.  Evaluation results are forthcoming.

Description: 

In this experiment, students will synthesize and characterize an iron complex followed by completion of two series of catalytic cross-coupling reactions mimicking the methodology utilized by organometallic chemists to balance catalyst efficacy and substrate scope.  Initially the complex Fe(acac)3 [acac =  acetylacetone] is prepared.  Two sets of catalytic reactions are completed: one comparing different iron catalysts (Fe(acac)3, FeCl2, FeCl3) while the other compares substrates (4-chlorotoluene, 4-chlorobenzonitrile, 4-chlorotrifluorotoluene). This experiment was designed during the June 2015 “Improving Inorganic Chemistry Pedagogy” workshop funded by the Associated Colleges of the South.

Corequisites: 
Learning Goals: 

●      Prepare Fe(acac)3 and perform appropriate characterization.

●      Develop skills in manipulating chemicals in an air-free environment.

●      Determine efficacy of catalytic reactions (% product) using appropriate analytical technique

●      Provide explanations for differences in product yields grounded by inorganic theory

Equipment needs: 

FT-IR spectrometer

GC, GC/MS, or NMR spectrometer

Air-Free equipment to maintain nitrogen-environment 

Implementation Notes: 

This experiment will be piloted during the 2015-2016 school year.  As we collect data we will post additional information regarding experimental details and evaluation methods.  We welcome others in the VIPEr community to help us test this!  If you do try this, consider filling out the evaluation file attached and sending to lhabgood@rollins.edu.

Students will synthesize and characterize the iron complex individually.  Each student should complete an appropriate subset of the catalytic reactions such that the pooled class data has each catalytic reaction replicated in triplicate.  The Fe(acac)3 complex is commercially available so it is possible to complete the lab in two sessions if students are provided with all three catalysts initially.

Time Required: 
Three 3-hour lab sessions: (1) Synthesize iron complex, demonstrate air-free techniques, (2) Perform catalytic reactions with appropriate analysis for product yield, (3) Complete catalytic reactions with appropriate analysis for product

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