Indirect nuclear 57Fe-13C and 57Fe-1H spin-spin coupling in ferrocenes and cyclopentadienyliron complexes:: measurements and DFT calculations

Several Fe-57-labeled ferrocene derivatives and other cyclopentadienyhron complexes were studied by Fe-57 and C-13 NMR with respect to isotope-induced chemical shifts (1)Delta(12/13)C(Fe-57) and the magnitude and sign of coupling constants (1)J(Fe-57,C-13) and (2)J(Fe-57,H-1). The geometries of the complexes were optimized by DFT methods [B3LYP/6-311+G(d,p)] and chemical shifts (GIAO) and coupling constants were calculated at the same level of theory. The trends in calculated Fe-57 nuclear shielding agree well with the experimental data and, in the case of coupling constants (1)J(Fe-57,C-13) and (2)J(Fe-57,H-1), both sign and magnitude are correctly reproduced. Copyright (C) 2004 John Wiley Sons, Ltd.