Calculation of lanthanide-induced shifts from molecular structure

The NMR spectra of Ln(thd)3(sub)2 (where Ln = Pr, Sm, Dy, Ho, Er, Yb, and sub = 3-pic and 3,5-lut) in CS2 were observed at 300C and the lanthanide-induced shifts for all protons, including those of the chelate, were calculated using the complete dipolar shift equation. The values for the magnetic anisotropy parameters D1 and D2 and the location of the x magnetic axis were obtained by a least-squares fit of the observed data. The calculated magnetic anisotropies were found to be in fair to good agreement with the single-crystal anisotropy data. It was found that the location of the x magnetic axis was the parameter most sensitive to errors in the procedure. (author)