Periodic trends

1 Apr 2013

Online Courses Directory

Submitted by Adam R. Johnson, Harvey Mudd College
Description: 

This website is a free and comprehensive resource that is a collection of open college courses that spans videos, audio lectures, and notes given by professors at a variety of universities. The website is designed to be friendly and designed to be easily accessed on any mobile device.

Course Level: 
Prerequisites: 
Corequisites: 
10 Oct 2012

Metal-Ligand Multiple Bonds and Frustrated Lewis Pairs

Submitted by Matt Whited, Carleton College
Evaluation Methods: 

I suggest evaluating learning through a class discussion where different students (or groups) present answers to different questions and solicit comments and/or responses.  A number of these questions are open-ended enough that there should be room for discussion and disagreement.

The answers I have attached are only starting points.  I suspect that students will have other ideas and valuable insights.

Evaluation Results: 

I have not used this LO yet, though I hope to use a version of it (possibly a shortened version) for my inorganic course next spring.

I have used the review and some related questions for my research students to help them get their heads wrapped around a presentation they were giving on our research (which is related to aspects of the review) last summer.  It seemed to help them understand the concepts of Lewis acidity/basicity and the frontier MO basis for reactivity quite a bit better.

Since this LO is as yet untested, I am very happy to hear feedback!

Description: 

This is a literature-based activity that focuses on a review I recently published as part of a thematic series on C-H activation.

The review highlights similarities between the newly discovered frustrated Lewis pairs and polarized metal-ligand multiple bonds.  There are many ways to use the review, but the attached set of questions focuses on drawing analogies among seemingly diverse types of reactivity using frontier-molecular-orbital considerations.

Corequisites: 
Course Level: 
Learning Goals: 
  • Students should be able to use molecular-orbital theory to rationalize the electronic structure and observed reactivity of species containing polarized metal-ligand multiple bonds
  • Students should be able to draw analogies between the reactivity of organic/main-group molecules and many transition-metal species using frontier molecular-orbital arguments
Implementation Notes: 

I am hoping to use some version of this in my inorganic chemistry class next spring, but it is as yet untested in a classroom setting, though I have had my research students work through the review and some related questions as they prepared a presentation on our work several months ago.  Since it is more or less untested, I am especially happy to hear feedback!

Time Required: 
unknown (probably ~2 hrs outside class + in-class discussion)
19 Sep 2012

Using the curated data sets from Wolfram Research in Inorganic Chemistry

Submitted by Robert LeSuer, The College at Brockport, SUNY
Evaluation Methods: 

I have yet to develop assessment tools.

Evaluation Results: 

See above.  I'm presenting this activity a bit prematurely and will be conducting student evaluations in due time.

 

Description: 

Recent versions of Wolfram's Mathematica software have access to a variety of curated data sets that are relevant to Chemists.  This activity is an example of how one can use the ElementData dataset to develop an on-line tool to explore periodic trends.  Wolfram provides a free web-based platform (the FreeCDF plugin) to view and interact with specifically designed Mathematica files.  The activity can be accessed in one of three ways:

(1) a version of the activity is currently active at http://www.bobthechemist.com/index.php/interactive-chemistry

(2) use the CDF file in the attached compressed folder.  The CDF can be saved to a personal computer and opened in a web browser once the FreeCDF browser plugin has been installed.

(3) use the notebook file in the attached compressed folder.  The notebook can be opened in Mathematica and allows for modification of the content in the activity.

Neither experience with Mathematica nor a Mathematica license are necessary to use this activity, which can be accessed by anyone through the first option above.

Learning Goals: 

Learning goals are based on Bloom's taxonomy.

A student should be able to:

- identify common periodic trends such as how ionization energy and atomic radius change across a family and down a group. (Knowledge)

- summarize the relationships between various elemental properites (Comprehension)

- predict properties of elements based on fitting trends to primitive emperical relationships (linear, logarithmic, inverse) (Application)

- analyze graphs for elements that do not seem to follow the periodic trends (Analysis)

- categorize elements based on their periodic properties (Synthesis)

- support the use of an element (or elements) for a given application based on its/their properties (Evaluation)

Prerequisites: 
Corequisites: 
Course Level: 
Topics Covered: 
Equipment needs: 

The Mathematica FreeCDF browser plugin, available at http://www.wolfram.com/cdf-player/, is required to view and use the activity.  A Mathematica license is required to view, use and modify the activity.  Attempts have been made to create a Smartboard-friendly interface.  In the current form, the tooltip pop-up text which labels each point with the corresponding atomic symbol will not function properly with a typical Smartboard interface.

 

Subdiscipline: 
Implementation Notes: 

This activity has been implemented in a junior-level (pre-pchem) inorganic chemistry class to help review the common periodic trends that were originally introduced in General Chemistry.  I am providing this activity to the public prior to spending much time using it in the classroom.

While I use this activity in a classroom setting, it may be more appropriate to view the activity as a homework/self-study/web resource. I post this and other Mathematica activities on our course management system (we use Moodle) and it appears as if students do use the activities outside of the classroom.  it may be appropriate to demonstrate the functionality in class and then assign a problem set for students to complete on their own.

I am interested in hearing about the experiences others have with the on-line version of this activity.  I have a number of years of Mathematica experience under my belt and may have made some assumptions that ultimately make the activity difficult for new users.  Please send me your comments, critiques and suggestions.

Time Required: 
15 minutes or more
30 Jul 2012

Backdonation Board Pins

Submitted by Lori Watson, Earlham College
Evaluation Methods: 

On the next lecture day, I gave a quick ungraded “quiz” with many of the factors listed and asked the students to circle those that would raise the IR stretching frequency. On the next formal quiz after this learning object I had a question with three pairs of compounds and asked them to circle which had the lowest IR stretching frequency and explain why.  I gave a similar question on the midterm exam.

Evaluation Results: 

10/10 students were able to circle the correct factors that would raise the IR stretching frequency on the day after the activity. On the formal quiz, the three part question was worth 9 points.  The average number of points awarded was 7.3/9, with a high of 9 and a low of 2.5. The most common mistake was on determining what would happen with backbonding to CO when considering trans ligands of different types.  One student had the reasoning correct but reversed which way the IR stretch went when backbonding increased.  On the midterm exam on the 3 point question most directly assessing their understanding of factors that influence back donation, the average score was 2.8.

Description: 

 

This activity works to reinforce the various factors that affect M --> CO backbonding and the resultant effects on CO bond stretch.  The attached properties are written on notecards and the students broken up into small groups (3-4 per group). They are given a selection of the cards (making sure the same group doesn’t get both items of a pair) and poster putty and asked to divide the cards up into factors that raise the CO stretching frequency and factors that lower it.  Those two categories are written on the board and the students then pin up the cards in their appropriate spot. After all of the groups are done, I indicate whether everything is correct (or not).  If some cards are in the wrong spot, the students have to come to consensus about which cards have to move.

Learning Goals: 

A student should be able to apply his/her knowledge of factors influencing the degree of backdonation into the pi* orbital of CO to predict (qualitatively) CO bond stretch frequencies.  The student should understand related factors (i.e. bond length, bond order) and how they are related to the CO stretching frequency.

Prerequisites: 
Corequisites: 
Equipment needs: 

Note cards and poster putty and a chalk/white board.  One could also use post it notes instead.

Course Level: 
Subdiscipline: 
Implementation Notes: 

I used this in my Organometallics course (10 students) in the spring of 2012, but could also imagine using it in my regular Inorganic course.  The students had read some background reading on backdonation for class, and about half of them had already had Inorganic Chemistry in which we talk about backdonation and its effects briefly. I split the students up into three groups and gave them 5 minutes to put their cards into the two categories on the board.  They initially got several incorrect.  In most cases it was obvious as both cards of a pair (for example: increase in pi donation/pi acidity of the trans ligand) ended up in the same category. The students discussed the incorrect cards, came to a consensus about which ones to more, and moved them.  All were correct by the 3rd try.  One could expand the number of cards (which would be necessary for a larger class) by including a number of cards with pairs of compounds on them (i.e. Ti(CO)6−2 , Fe(CO)62+) and ask whether the 2nd compound has a higher or lower IR stretch than the former.

Time Required: 
15 minutes
19 Jul 2012
Description: 

This is a great web resource for all types of nano materials.  There are lesson plans, demos, activites, labs and lots of background information.  It is very easy to navigate and there are videos of the labs so you can see each step - very useful when doing a type of synthesis or technique new to you.

Prerequisites: 
Corequisites: 
Implementation Notes: 

Students and instructors are able to watch videos and view safety info on a large number of nanomaterials labs and activities.  Truly a variety of skill and equipment levels but very well explained so you know what to expect.

I have used the ferrofluid synthesis proceedure and added some questions and information from the J. Chem. Ed. article listed on the site.  It works very well but pay attention to the notes they include - the iron II chloride needs to be fresh so buy small bottles.

Time Required: 
5 minutes if you know what you want, hours to read it all.
17 Jul 2012
Evaluation Methods: 

This was a problem set graded on a 10-point scale (1 point per question).

If used as a classroom exercise, I would grade primarily on participation within groups and on the willingness of each group to attempt answering questions (and asking further questions).

Evaluation Results: 

With some help from me, the scores generally ranged from 8-10 (out of 10).  I did not encounter any major misconceptions, though I did need to direct several students to ref. 25 (the Sanford/Mayer paper on oxidatively induced reductive elimination from Pd(II), which they found very helpful).

Description: 

This is a literature excercise I used in my upper-level organometallic course to guide students through some of the important points of a detailed organic/organometallic paper.  I have found that the first hurdles in some of these papers involve getting students to the point where they can understand (a) what specific reaction is being performed, and (b) what the role of each reagent is.  This set of questions includes a mix of material, including some things that are specifically stated in the article and some that are implied or referenced elsewhere.  I found that excercises like this one, although time-intensive, really helped my students to gain confidence about reading long papers.

I assigned this as a problem set and strongly encouraged collaborative work, although I have also used similar exercises where I assigned the paper as pre-class reading and sent out some or all of the questions in advance, then had them work in groups in class and present their answers to specific questions.

Corequisites: 
Subdiscipline: 
Course Level: 
Learning Goals: 
  • The primary goal is for students to gain comfort and familiarity with the primary literature, in this instance a relatively long organic/organometallic paper.
  • A student should be able to read a paper containing a complicated organometallic reaction with many reagents and determine the role of each reagent and the overall transformation being promoted.
  • A student should be able to apply knowledge of periodic trends and basic organic chemistry to rationalize reactivity across a series of substrates, ligands, etc.
Implementation Notes: 

I have given this assignment once (the paper only came out last year), but got very positive feedback from the students.  It was assigned toward the end of a term-long organometallic chemistry course, during which the students had read quite a few (10-15) papers from the primary literature.  This was the longest paper assigned, and I did it with the goal of helping students to pull out important inorganic/organometallic information from a paper written by primarily synthetic organic chemists.

Students had a bit of trouble with a few of the problems, namely 4, 7, and 8 (which do not have suggestions directly in the text).  However, in the end they all performed well on the assignment and I suspect I will tweak this same literature exercise for the next time around.

Time Required: 
Variable (30-40 minutes in class if paper has already been read)
17 Jul 2012

Periodic Table Videos

Submitted by John Lee, University of Tennessee Chattanooga
Description: 

The periodic table video website was developed by a group from the University of Nottingham.  In addition to the link to the website there a link to a publication in Science on the website is included below.  This is a great website that has a periodic table hyperlinked by element to a you tube video on that particular element.  On any given element video you see a mixture of general properties of the element (lecture) and an experiment that shows the element.  In addition, a new subheading has been added at the top for molecular videos where (a somewhat random yet interesting) list of molecules is included.

Prerequisites: 
Learning Goals: 

A student can see periodic trends in a video demonstration.

The resource can be used to learn other information about an unknown element.

 

 

 

 

 

 

Corequisites: 
Implementation Notes: 

This website can be implemented as a video demonstration on a particular periodic trend or properties of a singlular element.  I am going to use this website as needed in my Fall descriptive inorganic chemistry class.  In addition, for those students who come in early before class starts we will have an element of the day, and view that element's video during the down time right before class starts (depending on the length hopefully some interesting discussion will come up before class starts).

Time Required: 
2 - 10 minutes
17 Jul 2012

Colored Note Cards as a Quick and Cheap Substitute for Clickers

Submitted by Chris Bradley, Mount St. Mary's University
Evaluation Methods: 

Use of the cards gives a rough "eyeball" evaluation of student learning throughout a lecture. Using the cards, for me at least, also provides a gauge of attendance as well and also if it waxes or wanes during the class period.

Description: 

For many years I have resisted using clickers, mainly because at our university there is no standard universal clicker. I wanted to keep student costs as low as possible but also desired the type of live feedback during a lecture that clicker questions can provide. In both my general chem. (200-300 students) and upper division courses (50-75 students), I now pass out 4 or 5 colored notecards on the first day of class and make sure everyone has one of each color. I then do clicker style questions and color code the different answer choices in powerpoint and ask them to hold up their choice after 15-60 seconds depending on the question. This has worked well to provide me instant feedback on difficult topics and doesn't end up singling out any particular student, which most students detest in larger lecture courses.   

 

Learning Goals: 

Students are able to provide feedback to the instructor on questions quickly and "anonymously" and allow one to adjust the direction of a lecture on the fly.   

Prerequisites: 
Corequisites: 
Equipment needs: 

NA

Implementation Notes: 

I typically use between 4-6 clicker questions during a 50 minute lecture. I'm sure someone could use more/less based on an individual's needs. I think the key is to use clicker style questions from the beginning of the class on a daily basis to remind students to bring the note cards in a book/binder/bag. This is really the only problem I have encountered- students often forget their cards. It is probably a wash though, as I'm sure students can also forget clickers.  

Time Required: 
1-5 minutes (depending on the problem)
16 Jul 2012
Evaluation Methods: 

Student learning will be assessed by how well they analyze the last few problems during the in-class discussion. Similar questions will also be included in tests and quizzes.

Description: 

This activity is meant to teach students about the types of homogeneous transition metal C-H bond functionalization catalysts. Before class, the students will read a short discussion of inner- and outer-sphere C-H bond functionalization catalysts. Then they will use their knowledge of transition metal oxidation states and ligands in order to assess whether a variety of catalysts react via inner- or outer-sphere pathways. Based on what they know about these catalysts, they will also decide whether or not the selectivity of these catalysts is mainly dictated by the C-H bond strengths of the substrates.

Learning Goals: 

A student should be able to predict

      - available oxidation states for metals in a variety of complexes.

      - whether a catalyst will undergo one- or two-electron chemistry based on the metal's available oxidation states.

      - ligands that will likely directly react with a C-H bond.

      - whether or not there are any open coordination sites around a metal center.

      - whether a C-H bond functionalization catalyst will react via an inner- or outer-sphere pathway.

      - whether the selectivity of a C-H bond functionalization catalyst will be mainly dictated by the C-H bond strengths

         in the substrates.

 

Corequisites: 
Course Level: 
Equipment needs: 

none

Implementation Notes: 

I have not yet attempted to implement this learning object. It is meant for an organometallic or advanced inorganic class.

Time Required: 
55 - 75 minutes in-class with 15 minutes of before-class reading
16 Jul 2012

Application of Organometallic Chemistry – Breaking the Inert C-H Bond

Submitted by John Lee, University of Tennessee Chattanooga
Evaluation Methods: 

The guided questions can be collected and graded. Alternatively, a qualitative score can be given based on class participation.

Description: 

This learning object is a literature discussion based on a paper published in Nature (Labinger, J. A.; Bercaw, J. E. Nature 2002, 417, 507-514; doi:10.1038/446391a) discussing the mechanisms of C-H activation by transition metal complexes. This is a topic that could be covered at the end of a section on organometallic chemistry that shows a “newer” application. The attached lecture notes start at organic chemistry, then asks a question and is followed by a brief description of the paper showing examples for different mechanisms. The last slide is a thought slide that can easily be removed that asks a question that builds both upon what was discussed in the lecture and previous organometallic lectures. A working knowledge of counting electrons is required before beginning this study.

Learning Goals: 

A student should be able to describe, in limited detail, the “five primary” mechanisms for C-H activation.

A student should be able to distinguish the basic characteristics between oxidative addition, sigma-bond metathesis and electrophilic substitution.

A student should be able to apply his/her knowledge of organometallic reactions to show these reactions in a catalytic cycle for C-H functionalization.

Course Level: 
Equipment needs: 

None

Implementation Notes: 

A copy of the paper and guided questions should be made available to students one week prior to the lecture.  A 15 minute powerpoint lecture is available, if needed.  At the end of the lecture allow the students to break into small groups to take a second attempt at their guided questions. During this time the instructor can walk around helping with both the guided questions and any other questions that might have arisen from the discussion.  Alternatively, if the presentation is not needed you can use the guided questions to lead the class in a discussion.

Time Required: 
50 minute lecture

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