Department of Chemistry, Shahid Bahonar University of Kerman, Kerman, I.R. IRAN
The 13C chemical shifts for a series of compounds which includes carboxylic acids, aldehydes, ethers, ketones and hydrocarbons were simulated by using the parametric techniques. The observed chemical shifts were related to numerically encoded structural parametes called descriptors. Two new electronic descriptors were added to the previous descriptors. Ploting of experimental versus calculated chemical shifts for 34 different carbons in the data set shows a standards deviation of 6.05 ppm and regression coefficient of 0.994.