QSPR study between the space structure and boiling point, thermodynamic properties of saturated alkanes

Density functional theory (DFT) calculations employing the Becke-Lee-Yang-Parr (B3LYP) functional combined with a popletype 6-31g (d, p) basis set were performed on the saturated chain alkanes. Accessed to coordinate data to calculate the new defined spatial distance index Y_w′, Y_hand Hartree-Fock (HF). The multiple linear regression (MLR) methods and back propagation neural network (BP) are used to establish the quantitative structure property correlation (QSPR) model between the structure characteristic index Y_w′, Y_h, HF and boiling point (Tb) or thermodynamic properties -Δ_fH₂₉₈^θ(g) of saturated alkanes. The correlation coefficient between predicted value and literature value of BP method is greater than 0.99, the correlation coefficient between predicted value and literature value of MLR method is greater than 0.9, the accuracy of prediction result is high, the model is reliable, and the physicochemical property of saturated alkanes is good qualitative research has theoretical significance.