A 13 C chemical shifts study of iodopyrazoles: experimental results and relativistic and non-relativistic calculations

This work reports the 13 C chemical shifts of 49 iodopyrazoles and the 15 N chemical shifts of 6 iodopyrazoles, most of them from the literature but a number of significant cases from the present work. Most experimental data were from solution studies but some of them correspond to the solid state (CPMAS). The calculations include non-relativistic calculations (nr-GIAO) and relativistic ones (ZORA, mDKS/B3LYP/VDZ and mDKS/B3LYP/VTZ). In the case of NH -pyrazoles, problems of tautomerism and desmotropy arise that have been also studied. The manuscript is dedicated to develop some equations containing corrections for heavy atoms to predict 13 C and 15 N chemical shifts.