Reactions Of α-Diimine-Stabilized Mg-Mg-Bonded Compounds With Organic Azides And Carbodiimides

The chemistry of metal-metal（multiple）bonded compounds has been continuing to attract much attention because they not only show fascinating structural and bonding features but also exhibit interesting reactivities.In 2007,two Mg-Mg-bonded compounds[L’MgMgL’]（L’=[（Ar）NC（NiPr₂）N（Ar）]^–（A）;L’={[（Ar）NC（Me）]₂CH}^–,Ar=Dipp）（B1）,which represent the first structurally characterized stable molecules metal-metal bonds,were reported.Since then,a few more Mg-Mg bonds have been added and,meanwhile,their reactivity has been studied.In 2009,we have been interested in the construction of metal-metal bonds by usingα-diimine ligands and succeeded in the synthesis of a Mg^I-Mg^I-bonded compound,[K（THF）₃]₂[L^2-Mg-MgL^2-]（1,L=[（2,6-iPr₂C₆H₃）NC（Me）]₂）.Then we studied the reactivities of the compound 1 with small molecules and the synthesis ofMg^I-Mg^I-bondedcompound9 withamoreconjugatedligands N,N’-bis（dipp）-phenanthrene-9,10-diimine（L²）.The products were characterized by X-ray crystallography,NMR,Elemental analysis and DFT computations to elucidate their electronic structures.This thesis consists of four parts:1.The development of metal-metal bonded compounds is introduced.The homonuclear metal-metal-bonded compounds of the Mg-Mg and their reactivities in the activation of small molecules have been summarized.2.Reactionoftheα-diimineligandsMg-Mg-bondedcompound,[K（THF）₃]₂[L^2-Mg-MgL^2-]（L=[（2,6-iPr₂C₆H₃）NC（Me）]₂）（1）with benzyl azide and tritylazide,respectively,affordedtwodimericmagnesiumcompounds,[L^（-H）Mg（μ-N=CHPh）₂MgL^（-H）]toluene(L^（-H）=[ArNC=（CH₂）C（Me）NAr])（2）and[K（Et₂O）]₂{LMg（THF）[μ-N（Ph）C（Ph）₂]₂MgL}（3）,through reductive dehydrogenation and phenyl migration of the corresponding nitrene intermediates.which have been characterized by crystal structure,EPR,IR,elemental analysis and DFT computations。3.Reduction of theα-diimine ligands Mg-Mg-bonded compound,[K（THF）₃]₂[L^2-Mg-MgL^2-]（L=[（2,6-iPr₂C₆H₃）NC（Me）]₂）（1）with Carbodiimides,through C-C Coupling or C-H Activation,afforded three magnesium compounds[LMg（THF）)（μ-CyNCNCy）₂Mg（THF）L]（6）,[LMg（μ-NCNSiMe₃）₂MgL]（k-THF）₂（7）and{LMg[μ-（2,6-ⁱPr₂C₆H₃）₂NCN]}（8）,which have been characterized by crystal structure,EPR,IR.4.The synthesis of an new Mg-Mg-bonded compound,[K（THF）₃]₂[L²Mg-MgL²]（9）with the ligands N,N’-bis（dipp）-phenanthrene-9,10-diimine（L²）,which has been characterized by crystal structure,NMR,UV-visible and fluorescence spectroscopy and DFT computations.