This in class activity focuses on the ambidentate ligand thiocyanate.  Students compare data for known compounds to data for unknowns to make the bonding assignments. Data is provided from Baer, C.; Pike, J. J. Chem. Ed. 2010, 87, 724 where the authors  have the students synthesize all the compounds and then complete the data analysis.  My course does not include a lab component but I want the students to use literature to support their learning.

Students are given the C-N and C-S stretching frequencies for four reference compounds and seven unknowns prior to class and told to make bonding assignments (M-NCS or M-SCN or M-SCN-M) for the next class period.  The data is such that students will probably only use one of the stretching frequencies sets to make their assignments and in the process make incorrect conclusions.  Once in class, we discuss their conclusions and why the analysis is not straight forward.  They are then introduced to a quantitative comparison method and spreadsheets are used to quickly provide the differences between each unknown compound and each reference.  Details are provided in a faculty only file.