N-P Bifunctional Ligands Supported Complexes With Ln-Pd Bond

This thesis mainly focuses on the synthesis,characterization and reactivity studies of heterobimetallic complexes with rare-earth-palladium bond supported by N-P bifunctional ligands.The synthesis of heterobimetallic rare-earth metal compelxes with iron,cobalt and nickel was also briefly studied.The thesis included following parts:1.Rare-earth metal amido complexes L₃¹Ln（Ln=Sc,Y,Lu）with fexible phosphinomethylamido ligand were synthesized via alkane elimination reactions between the Ph₂PCH₂NHAd（L¹H,Ad:Adamantane）and（Me₃Si CH₂）₃Ln（THF）₂.Further reaction of L₃¹Ln with Pd（PPh₃）₄ afforded the corresponding Ln-Pd（Ln=Sc,Y,Lu）complexes which were charachterized by NMR spectroscopy,X-Ray diffraction studies,cyclovotammetry,elemental analysis as well as computational studies to disclose the first Pd→Sc dative bond.The Lewis acidic nature of Sc（III）strongly affected the electronic property of Pd（0）center to facillite the coordation with CO and ^tBu NC,meanwhile the ligation ofσ-donor on Pd（0）also led to a weakened Pd→Sc bond.The reaction of Sc-Pd complex with Me I unexpected led to a P-C bond cleavge/formation process and led to the isolation of an iodo group bridged Sc（III）-Pd（0）complex.2.Rare-earth metal amido complexes L₃²Ln（Ln=Sc,Y,Lu,Yb,Dy,Gd,Sm）with rigid phosphinoamido ligand were synthesized via either alkane elimination reactions between the Ph₂PCH₂NHAd（L²H）and（Me₃Si CH₂）₃Ln（THF）₂,or an“one pot”salt elimination reaction with Me₃Si CH₂Li and Sc Cl₃（THF）₃.Reactions of L₃²Ln were further studied to assemble heterobimetallic complexes with rare-earth-palladium bond.1)Metallation of L₃²Ln with（Ph₃P）₄Pd afforded Ln（III）-Pd（0）complexes L₃²Ln Pd（PPh₃）in which the Pd（0）center further coordinate with a Ph₃P ligand.Dynamic behavior due to the facile coordination/dissociation of the phosphinoamido ligand was disclosed in these complexes.Detailed characterization with NMR spectroscopy,X-Ray diffraction studies,cyclovotammetry,elemental analysis as well as computational studies revealed weakened Pd→Ln bonds in current system due to the ligation of extra Ph₃P ligand.Reactivities studies of L₃²YPd（PPh₃）showed an FLP-type reaction toward diphenylketene to form a zwitterionic complex,while a halide abstraction by the Y（III）center that led to the collapse of the Y-Pd core and formation of phosphinimine product.Reaction of L₃²Yb Pd（PPh₃）with diphenyldisulfide afforded a dithiolate complex where the oxidative addition occurred on Pd（0）center but the ligation of both Ph S^-occurred on Sc（III）center.2)Metallation of L₃²Ln with（COD）Pd（CH₂Si Me₃）₂ afforded Ln（III）-Pd（0）complexes（L₃²Ln Pd）₂（COD）featuring a 1,5-cyclooctadiene that bridges two Pd（0）centers,excepted for the scandium complex L₃²Ln which led to the isolation of a C₃-symmetric complex L₃²Sc Pd with so far shortest Sc-Pd bond.All these compounds were characterized by NMR spectroscopy,X-Ray diffraction studies,and elemental analysis.The reactions of L₃²Sc Pd and（L₃²YPd）₂（COD）with diphenyldisulfide afforded a dithiolate complex with two Ph S^-ligated to the Ln（III）centers.3)Reduction of L₃²Yb Pd（PPh₃）with KC₈/18-c-6 led to the isolation of the first Yb（II）-Pd（0）complex feature a Pd（0）→Yb（II）dative bond,which was characterized by NMR spectroscopy,X-Ray diffraction studies,and elemental analysis.3.The synthesis of heterobimetallic rare-earth metal compelxes with iron,cobalt and nickel was briefly studied.1)Reaction of L₃²Y with the divalent salts MCl₂（M=Fe,Co,Ni）led to the isolation of heterobimetallic Y（III）-Ni（II）,Y（III）-Co（II）complexes as well as a diiron chloride complex L₃²Fe₂Cl due to the chloride ion abstraction by Y（III）centers and the ligand distribution processes.Under reduction conditions,the reaction of L₃²Y with Co Cl₂afforded a reduced dicobalt complex L₃²Co₂Cl K（18-c-6）.2)Reaction ofβ-diketiminate yttrium bis-amido complex L^nacnacY（Ph NCH₂PPh₂）₂with Fe Cl₂ also led to the isolation of a diiron chloride complex due to the chloride ion abstraction by Y（III）and ligand redistribution.However,heterbimetallic Y（III）-Co（II）and Y（III）-Co（I）complexes could be obtained via the reaction of L^nacnacY（Ph NCH₂PPh₂）₂ with Co（I）precusors,such as（Ph₃P）₃Co Cl and（Ph₃P）₃Co I,respectively.In the former reaction,a P-C bond cleavge was observed.