A Simple and General Method to Determine Reliable Pseudocontact Shifts in Lanthanide Complexes.

Pseudocontact shifts (PCS) contain a wealth of geometric information, which makes paramagnetic NMR one of the best methods for accurate geometric determinations in solution. It is well-known that PCS are intrinsically linked to Fermi contact (FC) shifts, and die separation of the two terms is achieved through linearization methods, which heavily rely on (a) isostructurality (even concerning a labile axial site) and (b) die validity of Bleaney's constants. Recently we proposed a method that circumvents both assumptions in the case of axially symmetric complexes, and presendy we generalize it to lower symmetry. Our metiiod is model-free and thus does not rely on any structural hypothesis. Our results compare very well with recendy published data obtained through an accurate ab initio approach. [ABSTRACT FROM AUTHOR]