Chinese Journal of Magnetic Resonance ›› 2009, Vol. 26 ›› Issue (1): 58-74.

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Influence of Substituent Effects on the 13C NMR Chemical Shifts of Aliphatic Alcohols

YI Gui-yuan; CAO Chen-zhong*   

  1. (School of Chemistry and Chemical Engineering, Hunan University of Science and Technology, iangtan 411201,China)
  • Received:2008-07-17 Revised:2008-08-22 Online:2009-03-05 Published:2009-12-05
  • Contact: CAO Chen-zhong

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

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