Syntheses and characterization of Cp2Ce[η3-N(QPPh2)2] (Q = S, Se) and Cp2Ce[η3-N(SPiPr2)(SePPh2)]

The compounds Cp2Ce[η3-N(QPPh2)2] (Q = S (1), Se (2)) and Cp2Ce[η3-N(SPiPr2)(SePPh2)] (3) have been synthesized from the protonolysis reactions between Cp3Ce and HN(QPPh2)2 or HN(SPiPr2)(SePPh2) in THF. The structures of these compounds have been determined by X-ray crystallographic methods. The three compounds have similar structures in which the ligands are coordinated to Cp2Ce moiety in an η3 fashion through the two chalcogen atoms and an N atom. Whereas the 77Se NMR resonances are normal the 31P NMR resonances are shifted to much lower frequencies than in similar rare-earth compounds.