?Correlation between experimental and DFT/GIAO computed 13C NMR chemical shifts of organic compounds. Effects of asymmetry?

BORKOWSKI EDUARDO; ALVAREZ, MAR{IA; SUVIRE FERNANDO; ENRIZ RICARDO

Opena Natural Products Journal

betham

Año: 2012 vol. 5 p. 1 - 6

1874-8481

The experimental 13C chemical shifts of five different series of organic compounds are compared with pre-dicted 13C NMR chemical shifts obtained via empirically scaled GIAO shieldings. Our results indicate that the inclusion of a scaling factor allow to obtain an excellent correlation between δcalc and δexp. Although the inclusion of asymmetry im-proves this correlation, such enhancement was not observed for all the 54 tested compounds. We found RMS, a parameter related with the structural feature of the whole molecule, which could indicate the benefits of including asymmetry in these calculations