Activation strain model
Mathematical model for modelling chemical reactions / From Wikipedia, the free encyclopedia
The activation strain model, also referred to as the distortion/interaction model, is a computational tool for modeling and understanding the potential energy curves of a chemical reaction as a function of reaction coordinate (ζ), as portrayed in reaction coordinate diagrams.[1] The activation strain model decomposes these energy curves into 2 terms: the strain of the reactant molecules as they undergo a distortion and the interaction between these reactant molecules. A particularly important aspect of this type of analysis compared others is that it describes the energetics of the reaction in terms of the original reactant molecules and describes their distortion and interaction using intuitive models such as molecular orbital theory that are capable using most quantum chemical programs.[2] Such a model allows for the calculation of transition state energies, and hence the activation energy, of a particular reaction mechanism and allows the model to be used as a predictive tool for describing competitive mechanisms and relative preference for certain pathways. In chemistry literature, the activation strain model has been used for modeling bimolecular reactions like SN2 and E2 reactions, transition metal mediated C-H bond activation, 1,3-dipolar cycloaddition reactions, among others.[2][1][3]