Accurately mapping chemical space for reactions involving metal catalysts is affected by a multitude of factors that are treatable with quantum chemical simulation. While ligand-metal binding energies are commonly studied, understanding the entropy associated with the number of possible conformers that exist at equilibrium is also crucial. This is especially true if quantum chemical methods hope to make accurate predictions about chemical reactivity, without insight from experiment. The impact that ligand flexibility has on entropy with metal-ligand complexes can be investigated by systematically generating ligand conformers and binding these to the metal in various multidentate schemes. In this way, the lowest energy intermediates and overall entropy of the system can be evaluated. In this talk, a new method for ligand conformational analysis was applied to the binding of ethylenediaminetetraacetic acid (EDTA) with a series of metal cations. The investigation provides insight as to how the flexibility of EDTA and the chemical properties of the metal center affect the number of low energy chelated structures at equilibrium. This presentation will provide details on this new tool’s ability to explore the impact of ligand flexibility on entropy, as well as how it can be utilized in future investigations of metal-catalyzed reactions. <br/>

Understanding entropy of metal-ligand complexes

254th National Meeting (2017)

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