An Ylidic Cp and its Scandium Complexes in Equilibrium

Abstract

Scandium complexes bearing a C-ylidic, electron-deficient Cp ligand are presented by starting from [ScCl 3 (thf) 3 ]. As ylidic ligands do not require salt metathesis, the coordination of the Cp ligand is realized by mere substitution of the tetrahydrofuran ligands. In acetonitrile an equilibrium among the free ligand, the half-sandwich complex, and the cationic metallocene with its tetrachloridoscandate counterion is observed via NMR spectroscopy. This equilibrium is fully confirmed by 1 H and 45 Sc NMR EXSY experiments. In the absence of coordinating solvents, the selective formation of all compounds of the equilibrium has been achieved, and the structures have been confirmed by NMR spectroscopy and X-ray structure analysis. Especially 45 Sc NMR spectroscopy reveals signals with characteristic chemical shifts for the half-sandwich complex and the metallocene. With scandium triflate the corresponding scandocene is also accessible.

Rare-earth-metal trimethylsilylmethyl ate complexes

“…1 a ,2 Furthermore, only three examples of lanthanide complexes with the silylalkylidene ligand [CHSiMe 3 ] 2− have been reported, however, all of them with stabilizing ancillary ligands. 7 Since the NMR-active nuclei 89 Y ( I = 1/2) 8 and 45 Sc ( I = 7/2) 9 might provide useful complementary probes for assessing ate complexation and any involved decomposition reactions, we thought it worthwhile to revisit such rare-earth-metal neosilyl derivatives.…”