Computer-aided prediction of 125Te and 13C NMR chemical shifts of diorgano tellurides

This work describes a method to predict the 125Te and 13C NMR chemical shifts of diorgano tellurides based in a three-dimensional approach. For that, a collection of 150 compounds were selected from the literature and had their geometry optimized using the PM3 semi-empirical method. From this data, the structures were coded by the FOCOS program which described the chemical environment for each atom present in the structure, totalizing 1411 focos for the substances. The method developed was tested with ten diorgano tellurides not inserted in the database showing a higher accuracy in the prediction of 125Te and 13C NMR chemical shifts than those predicted by the commercial program. The chemical shifts and the statistical parameters obtained in this work demonstrate that the method applied was able to predict successfully the 13C and 125Te NMR chemical shifts of the diorgano tellurides. (author)