A Comprehensive Solute-Medium Interaction Model for Anisotropic NMR Data Prediction

Prediction of order parameters and hence anisotropic NMR data of a molecule dissolved in a dilute alignment medium can provide a unique means of solving certain challenging structural elucidation problems. Here, a general prediction model based on solute-medium interactions is developed featuring the use of medium-specific parameters as only fitting variables to depict intermolecular interactions in an alignment system, including repulsive, dispersive, and electrostatic interactions between the solute and the medium polymer, as well as their interactions with implicit solvent. This model is implemented on the framework of a surface decomposition method previously designed to formalize medium-induced solute alignment without a priori knowledge of medium structure. Having descriptors for all interactions, the new model performs significantly better than the original hard-body model when the medium and solute exhibit strong electrostatic and dispersion interactions. This model offers a general method to extract physical properties of a medium polymer by combining the experimental NMR data of different model compounds and then use these properties to predict the NMR data of other molecules of interest.