Spectroscopy and Structural Methods

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
9 Jun 2020

Gold carbonyl complexes

Submitted by Adam R. Johnson, Harvey Mudd College
Evaluation Methods: 

the first 3 problems are skill practice. The fourth problem is tough and would lead natrually to an in class discussion of bonding models, and how theories change over time.

Evaluation Results: 

I don't have any, unfortunately. 

Description: 

I've been meaning to write an LO on non-classical metal carbonyl complexes for a long time. This paper describes the synthesis and characterization of a gold carbonyl prepared in superacidic media. The LO asks the students to do some relatively straightforward reduced mass calculations to predict the 13C labeled CO stretch from the unlabeled one, but then asks the students to think about /why/ the Au-CO stretch is /higher/ than that of free CO.

Learning Goals: 

Students will practice using reduced mass calculations to calculate labeled stretching frequencies

Students will practice the Dewar-Chatt-Duncanson model of bonding

Students will use an MO diagram and their understanding of MOs to answer the question as to why the CO stretch in a non-classical carbonyl is higher than that of free CO

 

Equipment needs: 

none

Corequisites: 
Course Level: 
Implementation Notes: 

This is billed as an in-class activity because the fourth question is quite difficult. I assigned it as a challenge homework problem during the COVID semester (Spring 2020) but no one did it as far as I can tell. 

Time Required: 
30 minutes with time for discussion at the end
19 May 2020

MO diagram for square planar methane guided inquiry

Submitted by Adam R. Johnson, Harvey Mudd College
Evaluation Methods: 

Since this is done in class, it is not graded. Since I correct their mistakes in real time, the final MO diagram is usualy almost perfect.

Evaluation Results: 

Students often want to have the electrons in the LGOs 'ride over' on the non-bonding MO instead of falling down to the lowest energy bonding MO. After pointing it out several times in class, students are generally better at using the aufbau principle.

Description: 

This guided inquiry activity takes students through the process of constructing an MO diagram for square planar methane. LGOs are constructed using a graphical approach. Students are guided through a process that allows them to use their MO diagram to make a claim about chemical properties.

Learning Goals: 

Students will derive the LGOs for methane in the D4h point group.

Students will derive the MO diagram for methane in the D4h point group.

Corequisites: 
Course Level: 
Equipment needs: 

none

Implementation Notes: 

This would come after spending several class periods developing LGOs for polyatomics.

I use this method (though not this detailed worksheet) every year in class. I have students divide up into teams and work together at the chalkboard on molecules like borane, methane, water, SF4, and others. I circulate through the class and correct their diagrams in real time. Then at the end, each team presents their MO diagram and its major features.

Time Required: 
30 minutes
19 May 2020

MO diagram for water guided inquiry

Submitted by Adam R. Johnson, Harvey Mudd College
Evaluation Methods: 

Since this is done in class, it is not graded. Since I correct their mistakes in real time, the final MO diagram is usualy almost perfect.

Evaluation Results: 

Students don't know which orbitals to mix to form MOs at first and need guidance.

Students don't really understand the concept of hybrid orbitals within the framework of MO theory until they see a few examples.

 

Description: 

This guided inquiry activity takes the students through the whole process of constructing an MO diagram for water in detail. The LGOs are constructed using my graphical approach (linked below) and hybrid orbital formation is discussed. Along the way, students are given hints on what to think about when constructing an MO diagram.

Learning Goals: 

Students will derive the LGOs for water.

Students will derive the MO diagram for water without sp mixing.

Students will derive the MO diagram for water with sp mixing.

 

Corequisites: 
Course Level: 
Equipment needs: 

none

Implementation Notes: 

This would come after spending several class periods developing LGOs for polyatomics.

I use this method (though not this detailed worksheet) every year in class. I have students divide up into teams and work together at the chalkboard on molecules like borane, methane, water, SF4, and others. I circulate through the class and correct their diagrams in real time. Then at the end, each team presents their MO diagram and its major features.

Time Required: 
30 minutes
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: 
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.

Equipment needs: 

be able to view PDF/PNG files

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
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.

20 Mar 2020

virtual inorganic lab experiments with data

Submitted by Adam R. Johnson, Harvey Mudd College

This collection includes new and/or updated lab experiments useful for online/distance learning. To be included in this collection, data should be provided for others to use in their new virtual laboratory courses. This collection was prepared as part of my response to the COVID-19 pandemic.

Prerequisites: 
Corequisites: 
Course Level: 
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.

9 Jan 2020

Marvin suite from ChemAxon

Submitted by Anthony L. Fernandez, Merrimack College
Evaluation Methods: 

As my students draw structures, I usually observe them and make suggestions to improve their drawings. 

Evaluation Results: 

While I do no formal assessment of this activity, I have observed that students seem to learn how to use the program fairly quickly and then use it without much difficulty for the rest of the semester.

Description: 

It is important for students to be able to effectively communicate the results of their scientific work. This does not only inlcude written and oral communication, but the creation of appropriate representations of the complexes they have investigated. It is crucial that students learn how to draw molecules using electronic structure drawing programs, but site licenses for structure drawing programs can be prohibitive for some institutions.

Marvin suite is a software package from ChemAxon that is freely avaialble for educational institutions. It contains a structure drawing program (MarvinSketch) and a viewer (MarvinView), as well as tools that allow for the calculation of many molecular and spectroscopic properties of molecules. This is a very useful suite of programs that can be used by all students and faculty at an instituion once an Academic License is obtained.

A set of directions for drawing a coordination complex in MarvinSketch is also included as part of this learning object. These directions will guide the user as they draw the structure of a square-planar coordination complex, trans-[Ni(NCS)2(PMe3)2].

Corequisites: 
Prerequisites: 
Learning Goals: 

After following the instructions, students should be able to draw a chemical structure electronically using a chemical structure drawing program.

Once the structure in drawn in the program, a user would then be able to access the many other functions available in the software.

Implementation Notes: 

During the first week of our semester, lab sections are usually not held for courses so that student enrollment issues can be sorted out. In an advanced course such as Inorganic Chemistry, I want to take advantage of every week that I can so I use the first lab meeting time to have students learn how to use several software programs that they wil use over the course of the semester. 

I post the download link and the license file for the software on the course LMS before the lab period and I ask the students to download and install the software. You should make sure that students update their Java installation before installing the Marvin suite. (I also place a link to the Java download site on the course LMS as well, but students tend to ignore it.) Aside from the Java issue, I have found that there are no real issues encountered by students when they install the software. 

When we meet, I ask the students to follow the linked instructions to create a drawing of a coordination complex. Once they complete that successfully, I ask them to draw several other structures. I do not  have any specific structures that I use, but I try to choose complexes with different geometries (octahedral, tetrahedral, square pyramidal, etc.) around the metal center.

The Marvin suite of programs provides the students with a number of useful tools, not just a structure drawing progam. Students use this to calculate or estimate a number of different things, such as the molecular mass, the elemental analysis, a mass spectrum, 1H and 13C NMR, and charge distribution.

To obtain a license file, the faculty member must log into the ChemAxon site and request an Academic License. Once approved, the instituion is allowed to use the software for 2 years and the license can be easily renewed when it expires.

 

Time Required: 
30 minutes
8 Jan 2020

How to Read a Journal Article: Analyzing Author Roles and Article Components

Submitted by Catherine McCusker, East Tennessee State University
Evaluation Methods: 

Follow up small group work with a class discussion of the correct answers. Grade students on participation and completness

Description: 

This literature discussion uses a recently published article on solvatochromic Mo complexes to introduce students to the different components of a research article. The activity is divied into to two parts. Before class students read the paper and focus on defining terms, investigating the "meta" data of the paper, and the different sections iof the paper. In class the students work in groups to investigate the scientific content of the paper

Prerequisites: 
Course Level: 
Corequisites: 
Learning Goals: 

Students should be able to:

  • Interpret the roles that authors play in a research project
  • Recognize the different sections of a research article and the purpose of each section
  • Understand how to access supporting information and the type of information found there
  • Find key conclusions of a research paper and the experimental evidence the author used to make those conclusions
Time Required: 
~30 min (if students complete part 1 before class)

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