NMR spectroscopy

[king87]

Hi,

 

i have been wondering about the influence of the ligands on metal NMR shifts, for complexes with metal like Pd, the ligands are 2 amine ligands, and they have also two chlorides in structure, cis or trans geometry. In DMF, when comparing the difference between the chemical shifts of the same complexes (the same ligands) but with different geometry, for cyclic amines like cyclopropyl-cyclohexyl, is small, and trans-compounds signal are more shielded. The opposite situation is for ths type of coplex with NH3, MeNH2 or Adamantylamine ligands, trans more deshielded than cis, and the difference between cis and trans is biggest for adamantylamine compounds, while for rest is veeery small. What can be the reason?

 

Greetings.