Reversible Yttrium Alkynide Coupling Supported by DAC (Deprotonated 4,13-Diaza-18-crown-6) Ligation
摘要:
The reaction of Y(DAC)(CH(2)SiMe(3)) (1) with phenylacetylene produces an equilibrium mixture of the alkynide-coupled butatrienediyl complex [Y(mu-DAC)](2)(mu(Z)-PhC=C=C=CPh) (2) and the uncoupled bridging alkynide dimer [(DAC)Y(mu-C=CPh)](2) (3). Unlike other butatrienediyl complexes of yttrium or the lanthanides, this unit adopts a Z conformation, in complex 2.
Synthesis, X-ray Crystal Structure, and Thermal Stability of Y[DAC][CH2SiMe3] (DAC = Deprotonated 4,13-Diaza-18-crown-6)
摘要:
The deprotonated 4,13-diaza-18-crown-6 (DAC) ligand system allows isolation of the yttrium alkyl species Y(DAC)(CH(2)SiMe(3)). A crystallographic investigation reveals a monomeric complex containing a seven-coordinate yttrium center exhibiting no agostic interactions with the alkyl group. The complex is relatively stable in the solid state but decomposes by ligand metalation in solution.