ИСТИНА

In this study, we discuss results of experimental measurements of H-bond with using IR and UV spectrophotometry, NMR spectroscopy and calorimetry for calculations of thermodynamic quantities logK, DG and DH of hydrogen bonding in organic solution. We conclude, that known data level makes it possible to extensive QSPR (Quantitative Structure–Property Relationships) modeling allowing very quick and precise calculation of the strength or thermodynamic quantities of hydrogen bonding, that would be applicable for the wide variety of the HBD and HBA. The estimation of the H-bond strength is based on the Gibbs energy DG for the 1:1 hydrogen bond complexation (1) of different HBDs with different HBDs, which represent for up to now the largest, structurally diversified dataset at 298 K in CCl4. The Gibbs energy for the dataset of 3373 reactions (1) was modeled by Support Vector Machine and Multiple Linear Regression methods using ISIDA Fragment descriptors. Successfully cross-validating models were then challenged to make predictions for an external test set of 629 H-bond complexes. The best consensus models perform well both in external cross-validation (root mean squared error RMSE = 1.5 - 2.3 kJ/mol) and external test set predictions with the RMSE within the range 2.2 - 5.0 kJ/mol depending on the class of Applicability Domain. The consensus models elaborated for the complexes with single hydrogen bond were successfully applied for predictions of the Gibbs energy for some complexes with two cooperative hydrogen bonds for hydrogen-bonding dimers and bifurcated hydrogen bond. A predictor of DG for hydrogen bond complexation of various organic donors with various acceptors was created on the base of the entire training set and the best models. The SVM consensus model is publically available on the server: http://infochim.u-strasbg.fr/webserv/VSEngine.html.