Synthesis, reactivity, and structure of mixed-ligand ytterbium complexes supported by beta-diketiminate

摘要

The preparation and reaction chemistry of beta-diketiminate ytterbium complexes is described. Reaction of [(DIPPh)(2)nacnac]Li ((DIPPh)(2)nacnac = N,N-diisopropylphenyl-2,4-pentanediimine anion) with 1 equiv of anhydrous YbCl3 in THF, followed by crystallization from toluene, affords the monomeric complex [(DIPPh)2nacnac]YbCl2(THF)(2) (1) in high yield. Recrystallization of complex 1 from toluene gives an unexpected dimeric complex, {[(DIPPh)(2)-nacnac]YbCl(mu-Cl)(3)Yb[(DIPPh)(2)nacnac](THF)}(.)1/2MePh (2), which has a rare triple chloride bridge. Reaction of complex 1 with CH3C5H4Na in 1:1 molar ratio in THF gives the mixed-ligand ytterbium chloride (CH3C5H4)[(DIPPh)2nacnac]YbCl (3). Complex 3 readily undergoes metathesis reactions with 1 equiv of LiNPh2 or LiNPr2i in THF to form the compounds (CH3C5H4)[(DIPPh)(2)nacnac]YbNPh2 (4) and (CH3C5H4)[(DIPPh)2nacnac]YbNPr2i (5), respectively. The complexes 2, 3, and 4 have been characterized by an X-ray diffraction structure determination. [References: 36]