31 Jul 2017

Inorganic Nomenclature: Naming Coordination Compounds

In-Class Activity

Submitted by Gary L. Guillet, Georgia Southern University Armstrong Campus

I do not like to take a large amount of time in class to cover nomenclature of any kind though I want students to know the names of common ligands and the basic ideas of how coordination complexes are named.  Since it is a systematic topic I assign this guided inquiry worksheet.   The students complete it outside of class and can work at whatever pace they want.  If they are more familiar with the topics the can quickly complete it but if they are rusty or have not seen some of the material it gives them an easy entry point to ask questions to fill in any gaps in their knowledge.  This assignment covers determing charge on a metal in a complex with simple ligands, how to identify and name common isomers, and it is structured in a guided inquiry form. 

File Nomenclature Worksheet.docx158.29 KB
Learning Goals: 

Students will be able to identify and correctly name common ligands in a chemical structure or chemical name.

Students will be able to identify the charge on a metal or a ligand in a chemical structure.

Students will be able to identify common isomeric differences in a chemical structure or a chemical formula (cis, trans, fac, mer). 

Students will be able to use a chemical name to draw a chemical structure.

Equipment needs: 


Implementation Notes: 

I use this assignment to replace a lengthy lecture on the topic of nomenclature when covering coordination chemistry.  I have students complete this assignment outside of class.  I encourage them to work in pairs so students can jointly interpret the instructions and determine the patterns in naming complexes.  The assignment is constructed in a very straightforward manner and covers the basics of inorganic nomenclature.

Upon completion of the assignment I take about 15-20 minutes in class to quickly cover the main ideas of the assignment.  I field any questions that arose during the assignment and I do a few comprehension check type questions on the board. 

Time Required: 
1-2 hours
Evaluation Methods: 

For my course I grade this assignment as a problem set.  Upon collecting the assignment I do not exhaustively grade them.  I check them over for completness.  I tell the students when I hand it out that it is designed for them to learn and then test their own comprehension and if they are stuck they should bring issues to office hours. 

On the following exam I put two or three inorganic complex names and have the students draw the structures.  The test questions always incorporate isomerism in addition to combinations of common ligands and transition metals.

Evaluation Results: 

After completion of this assignment most students are able to draw straigthforward structures including some isomers on an exam.  They can identify common ligands from their names like water, ammonia, carbon monoxide.  They also understand the common conventions in naming including handling cis and trans isomers as well as fac and mer isomers.

In the most recent sample of ACS examinations (IN16D) 87% of my students answerd correctly on the question most directly related to this assignment, selecting the correct name of a given complex using a picture of the complex.  I do not have any comparative data from another teaching approach.

Creative Commons License: 
Creative Commons Licence


I used this worksheet in class last week on our first day of coordination compounds. The students hadn't really seen too many coordination compounds yet in class (except as point group assignment examples), because we've been doing a lot of group theory and bonding.  I thought this worksheet was a great way to introduce them to the typical conventions in inorganic, both in terms of naming but also in figuring out the charge on the metal, etc.

It did take my group (n = 19 students) pretty much the entire hour to work through the problems.  I can see why you'd assign this outside of class!  But I didn't mind using the class time. It was a very nice way for them to build their own knowledge.  Thanks!

I modified this as an in-class activity. We used just pages 3 and 5 of the worksheet, and I provided them with the figure 1 of structures. The students needed~20 min to complete this in pairs.  They were really quick at picking up on some of the general naming rules. Since I skipped over the first page that goes over determining charge on the metal (oxidation state), students did have a few questions on that, but I went over questions they had after the worksheet and was able to help them with this.

My students even noticed a few small errors. In figure 1, the complex shows Pd, but the structure lists Pt.  In question 2 on page 5 the name is "potassium trans-diacetylacetonatodicyanoferrate(III)"  shouldn't the name be "trans-bisacetylacetonato"

Overall, this was a great activity for teaching naming and helping the students realize the "rules" for themselves.  I plan to adopt this for all future classes.

I have used this LO the last two years in my inorganic course. I have done it both as an in-class guided inquiry exercise that was not collected but we went over the answers in class, and as an out-of-class exercise that I collected and graded (mostly for completeness, not correctness). I think this is a fantastic way to teach nomenclature because it walks the students through examples of ligands and complexes and shows /why/ we need to have different prefixes and names. Thanks, Gary!

The VIPEr community supports respectful and voluntary sharing. Click here for a description of our default Creative Commons license.