On the Complex Formation of Tris-(dipivalomethanato)-europium with Pyridine

The complexation of the shift reagent tris-(dipivalomethanato)-europium with pyridine in deuteriochloroform has been studied by means of ¹H-NMR. Shift parameters S = 28.0, 9.9, and 9.2 ppm respectively for pyridine protons 2, 3 and 4 are obtained. The results indicate that the shift reagent complexes a single pyridine molecule with an association constant K₁ > 100 mole^?1l.