Quantitative structure-property relationship of standard enthalpies of nitrogen oxides based on a MSR and LS-SVR algorithm predictions was written by Wan, Zhongyu. And the article was included in Journal of Molecular Structure in 2020.Electric Literature of C5H5NO This article mentions the following:
Quantum chem. method is used to calculate 1444 descriptors of each N oxide mol. Variables are screened by using multiple stepwise regression (MSR). The optimal 10-element regression equation is derived, its R2 = 0.934 and Q2 = 0.927. The support vector regression (SVR) model between 10 mol descriptors and standard formation enthalpy is established, and the support vector machine is optimized by using the least squares method (LS). The training set consisting of 78 compounds have R2 = 0.969 and Q2 = 0.954. The other 22 compounds constitute the test set to verify the external prediction ability of the model, and its R2 = 0.958. It demonstrates that the LS-SVR model has good stability and prediction ability, and overcomes the problem of over-fitting. The conclusion of quant. structural property relation (QSPR) shows that the mol. descriptor and the standard enthalpy of formation are nonlinear 2nd-order functions. The authors speculate that the electronegativity of atoms is the key to determine the standard enthalpy of formation of compounds In the experiment, the researchers used many compounds, for example, Pyridin-4-ol (cas: 626-64-2Electric Literature of C5H5NO).
Pyridin-4-ol (cas: 626-64-2) belongs to pyridine derivatives. Pyridine has a conjugated system of six π electrons that are delocalized over the ring. The molecule is planar and, thus, follows the Hückel criteria for aromatic systems. Several pyridine derivatives play important roles in biological systems. While its biosynthesis is not fully understood, nicotinic acid (vitamin B3) occurs in some bacteria, fungi, and mammals.Electric Literature of C5H5NO