This is a problem set developed for a Chemistry Capstone course for chemistry and biochemistry majors.  Students have had organic and analytical chemistry; however, they may not have taken inorganic or physical chemistry (biochemistry majors).  Students are given a general description of the topic and some information about the journal and are expected to find the article on their own.  They use this article to answer the questions.  These answers are submitted to instructor and these questions are then used as the basis for an in class literature discussion.

This article was chosen in order to introduce "Critical Thinking" (as defined by AAU&C - Critical thinking is a habit of mind characterized by the comprehensive exploration of issues, ideas, artifacts, and events before accepting or formulating an opinion or conclusion) into the Chemistry Capstone class.  The authors have synthesized a complex where the azide ligands bridge copper centers through covalent linkages.  They compare the stability of this cuprous azide complex to the stability of stictly ionic azide salts in Reference 9.  During the discussion session I ask if the students think that this is a valid comparison.  We discuss what will affect the N-N non bonding distance in ionic compounds (most focus on cation size) and then discuss what other factors will affect the N-N non bonding distance in a covalently bound complex such as the cuprous azide.  We also get into a discussion about which N-N non bonding distance the authors are referring to – Are they discussing the azides bonded to a single copper or are they discussing neighboring azides in different layers of the crystal.  This is not immediately apparent from reading the paper and we have had lengthy discussions between faculty members on this subject.  The idea of this discussion thread is to introduce the students to the possibility that the same information can be interpreted two different ways.  The last question on the problem set (When the [Cu₂(dmpyz)(N₃)₂] complex is added to the rocket propellant HMX thermal decomposition temperature decreases.  The authors state that “…complex (1) can catalyze the thermal decomposition of HMX, and the catalytic ability enhances with the increase of mass.”  Either support this statement or dispute it.) is asked to get the students to realize that not everything in a paper may be correct.  Most student focus on the fact that less heat is needed to cause the decomposition of HMX and say that yes, the complex catalyzes the decomposition.  This leads to a discussion of what does it mean to catalyze a reaction and can there be any other explanations for why the decomposition temperature decreases.