Syntheses, Characterizations,and Structures Of Organolanthanide Complexes Supported By β-Diketiminate

Three lanthanide dichlorides supported by p-diketiminate with different steric bulk were obtained, which can be used as precursors for further transformation. The reactivity of these complexes with C5H5Na was investigated.1. Reactions of anhydrous YbCl, with three lithium (3-diketiminates with different steric bulk, L'Li. L:Li. L3Li (L'=N,N-phenyl-2,4-pentanediimine anion. L2=N,N-dimethyl-phenyl-2,4-pentanediimine anion,L3=N-phenyl-N-diisopylphenyl-2,4-pentanediimine anion, in 1:1 molar ratio gave three corresponding lanthanide dichlorides . L'YbCl2(THF)2 1. L:YbCl2(THF)2 2. LTbCl2(THF)2 3. These lanthanides were characterized by elemental analysis.2. Complexes 1 and 2 reacted with C5H5Na in 1:1 molar ratio giving the disproportionation products, L'Yb(C5H5), 4 , L2Yb(C5H5)2 5, respectively. These two complexes were characterized by IR spectra, elemental analyses, MS and X-ray analyses. The results indicate that both complexes 4 and 5 are monomeric. The central metal atom Yb was coordinated by two cyclopentadienes and two nitrogen atoms of p-diketiminate to form a eight-coodinate distorted tetrahedral complex.3. P-diketiminate lanthanide monochloride L'YbCp(u-Cl),Li(THF), 6 was synthesized by the reaction of complex 3 with equiv molar of CsH5Na. Complex 6 was characterized by IR spectrum, elemental analysis, MS and X-ray analysis. The molecular structure determination shows the presence of two chloride-bridge bonds between the central metal Yb and lithium, and the coordinate number of the central metal is 7.4. The steric bulk of auxiliary ligand has significant effect on the reactivity of P-diketiminate lanthanide, when its lanthanide dichlorides reacted with CpNa in 1:1 molar ratio, p-diketiminates with more sterically bulk is favorable to produce desired lanthanide monochlorides, while less bulky one affords disproportionation products.