DFT study of molecular structures and 13C NMR parameters of two fluorinated biphenyls and their η6-tricarbonylchromium complexes

The molecular structures of 2,2'-difluoro-6,6'-dimethylbiphenyl, 4,5-difluoro-9,10-dihydrophenanthrene and of their eta(6)-tricarbonylchromium complexes have been discussed in the light of the results of molecular energy calculations. Also the isotropic magnetic shielding constants and carbon-fluorine spin-spin coupling constants for these objects have been calculated and compared with the experimental values of C-13 NMR chemical shifts and J constants. The calculational methods used were: DFT/BHandli/6-311++G(2d,p) and/or DFT/B3LYP/6-311++G(2d,p). It has been confirmed that experimental 13C NMR chemical shifts for eta 6-arene tricarbonylchromium complexes can be satisfactorily predicted using both methods, although the method exploiting BHandH functional is not able to reproduce the C-13 NMR chemical shifts of Cr(CO)(3) carbon atoms. On the other hand, this method provides the J(C-13, F-19) values which are close to the experimental ones. (C) 2015 Elsevier B.V. All rights reserved.