Infrared Spectroscopic Analysis of Linkage Isomerism in Metal−Thiocyanate Complexes

Abstract

We developed an experiment suitable for an advanced inorganic chemistry laboratory that utilizes a cooperative learning environment, which allows students to develop an empirical method of determining the bonding mode of a series of unknown metal−thiocyanate complexes. Students synthesize the metal−thiocyanate complexes and obtain the FT-IR spectrum of each one, along with reference complexes of known coordination. They are then asked to develop a quantitative approach of comparing the unknown metal−thiocyanate complexes to the references and deduce the most feasible bonding mode of each metal to the thiocyanate ligand, whether via the sulfur or nitrogen atom. The students can then explain their results using hard−soft acid−base concepts.