A Study On The Reactions Of Nickel(0) N-heterocyclic Carbene Complexes With Organic Azides

Terminal imido complexes of late transition metals have attracted great interest because of their unique reactivity of C-H bond amination and olefin aziridination.The reaction of iron?0?and cobalt?0?complexes with organic azides proved an effective way for the preparation of iron and cobalt terminal imido complexes.Inspired by this,the reactions of nickel?0?N-heterocyclic carbene?NHC?complexes with organic azides were investigated,and presented in this dissertation.1.The reaction of NHC-coordinated nickel?0?alkene complex[?IPr?Ni??²-CH₂CHSi Me₃?₂]with organic azide Dmp N₃ produced the two-coordinate imido complex[?IPr?Ni=NDmp]?1?in a trace amount with the starting materials being largely remained.The reaction of[?IPr?Ni??²-CH₂CHSi Me₃?₂]with the arylazide Dipp N₃ gave IPr NNNDipp?2?as the only isolable product.The interaction of[?IPr?Ni??²-CH₂CHSi Me₃?₂]with Ph C?CF₃?₂N₃ gave the azanickelacyclobutane complex[?IPr?Ni??-C,N-N?C?CF₃?₂Ph?CH?Si Me₃?CH₂?]?3?.Recrestallization of 3 led to the isolation if a new azanickelacyclobutane complex[?IPr?Ni??-C,N-N?C?CF₃?₂Ph?CH₂CHSi Me₃?]?4?andtraceamountof[?IPr?Ni?NHC?CF₃?₂Ph??CH₂CHNC?CF₃?₂Ph?]?5?.Complexes 3 and 4 were characterized by single crystal X-ray diffraction,elemental analysis,nuclear magnetic resonace,UV-vis-NIR,and FT-IR spectroscopies.The structure of complex 5 was also confirmed by single crystal X-ray diffraction.2.The interaction of[?IPr?Ni??⁶-toluene?]with Dmp N₃ produced the two-coordinate imido complex[?IPr?Ni=NDmp]?1?in high yield.The reaction of[?IPr?Ni??⁶-toluene?]with the azide bearing electron withdrawing substituent?3,5-?CF₃?₂C₆H₃N₃?produced a bridging imido complex[?IPr?Ni??²-NAr?₂Ni?IPr?]?Ar=3,5-?CF₃?₂C₆H₃??6?.Complexes 1 and 6 were characterized by single-crystal X-ray diffraction,nuclear magnetic resonace,UV-vis-NIR,and FT-IR spectroscopies.Complex 1 has a solution magnetic moment of 2.6?1??B,indicating its S=1 ground spin-state.