Synthesis And Reactivity Studies Of Heterobimetallic Rare-Earth-Nickel Complexes Supported By β-diketiminato Ligand

This thesis mainly studied the synthesis and characterization of heterobimetallic complexes with Ln-Ni（Ln=Y,Lu）bond supportedbyβ-diketiminato ligands,which included the following parts:1.Protonolysis ofβ-diketiminato（nacnac）rare-earth metal bis-alkyl complexes L^nacnacLn（CH₂SiMe₃）₂（THF）（Ln=Y,Lu）with 2 equiv.of Ph₂PCH₂NHPhor Ph₂PNHPhafforded the bis-amido complexes L^nacnacLn（Ph₂PCH₂NPh）₂（Ln=Y,Lu）and L^nacnacY（Ph₂PNPh）₂.Metallation of the latter complexes with 1 equiv.of Ni（COD）₂ or Ni（PPh₃）₄ led to the isolation of unusual heterobimetallic Ni（Ⅱ）-Ln（Ⅲ）complexes formed via P-C bond cleavage of one[Ph₂PCH₂NPh]^-ligand.Notably,both the imine PhN=CH₂ and phosphide[Ph₂P]^-fragments from the P-C bond cleavage were trapped in the Ni（Ⅱ）-Ln（Ⅲ）core with a relatively weak interaction between two metal centers.These complexes were fully characterized by ¹H,¹³C{¹H},³¹P{1H}NMR spectroscopy methods,elemental analysis as well as single crystal C-Ray diffraction studies.On the contrary,theβ-diketiminatoyttrium bis-amido complex L^nacnacY（Ph₂PNPh）₂ does not react with Ni（COD）₂ or Ni（PPh₃）₄ under similar conditions,highlighting the important role of the distance between the N and P donors during the formation of Y-Ni complex.2.The versatile reactivity of Ni（Ⅱ）-Y（Ⅲ）complex toward small molecules were studied,including the coordination of isonitrile to Ni（Ⅱ）center to form a 18e Ni（Ⅱ）center,insertion of nitrile into the M-N（M=Y,Ni）with concomitant regeneration of P-C bond that led to the coordination of another molecule of nitrile with Ni（Ⅱ）center,and ring-opening of epoxide by nucleophilic attack by the phosphide group from the sterically hindered carbon.These complexes were fully characterized by ¹H,³¹P{¹H}NMR spectroscopy methods,elemental analysis as well as single crystal X-Ray diffraction studies.These studies demonstrated the potential synergetic reactivity of heterobimetallic Y-Ni complex.