关键词: ¹³C化学位移, 核磁共振(NMR), 电负性, 静电场, 原子极化度, 立体效应, 脂肪醇

Abstract: An empirical model for calculating ¹³C chemical shifts of aliphatic alcohols was proposed, in which the parameters describing the chemical environment of the focused carbon atoms are in were used as the independent variables. The parameters included electronegativity, atomic polarizability and those representing the steric effects. The experimentally-measured ¹³C NMR chemical shifts of 747 carbon atoms in 120 model compounds (91 alcohols and 29 diols) were used as the training set to derive the weights for the independent variables. The correlation coefficient R of the model was found to be 0.998. Leave-one-out cross-validation demonstrated good predictive ability and stability of the model. The model proposed was used to calculate the ¹³C chemical shifts of 69 different carbon atoms in 5 compounds that were not included in the training set, and the results proven to be satisfactory. The proposed model may be useful for calculating ¹³C NMR chemical shifts in alcohols with complex structures.

Key words: ¹³C chemical shift, electronegativity, atomic polarizability, steric effect, alcohol