¹³C and ¹⁹F NMR chemical shifts of the iron carbene complex (CO)₄FeCF₂ - A case study at DFT level

The structure and chemical shifts of the carbene complex (CO)₄FeCF₂ were investigated at DFT level. The CF₂ ligand will occupy an equatorial position in a trigonal bipyramidal iron complex. The carbenic C atom is calculated to be much more deshielded with respect to the CO ligand at both BP86 and B3LYP level. Anisotropies of ¹³C chemical shifts of carbenic C can show us the certain direction where the attack of nucleophilic regents may take place. The ¹⁹F NMR chemical shift is predicted to be in the range of 160-180 ppm respect to the standard CCl₃F scale by GIAO calculations.