Zero-valent Cobalt, Iron, And Manganese Complexes With N-heterocyclic Carbene And Styrene Ligation

This thesis mainly discusses the synthesis,characterization and reactivity of zero-valent cobalt,iron and manganese complexes with N-heterocyclic carbenes?NHC?and styrene ligation.1.Synthesis and characterization of zero-valent metal complexes coordinated by N-heterocyclic carbenes?NHC?and styrene.The synthesis of the styrene-coordinated metal complex was achieved by a one-pot method.Treatment of the carbene ligand?IPr,IMes?,with metal chlorides?FeCl₂,CoCl₂,MnCl₂?,styrene and graphite potassium in tetrahydrofuran leads to the formation of the zero-valent metal styrene complexes [?IPr?Fe??²-CH₂CHPh?₂]?1?,[?IMes?Fe??²-CH₂CHPh?₂]?2?,[?IMes?Co??²-CH₂CHPh?₂]?3?,[?IMes?Co??²-CH₂CHPh?₂]?4?,[?IPr?Mn??²-CH₂CHPh?₂]?5?.Compounds 1-5 have been characterized by ¹H NMR spectroscopy,solution magnetic susceptibilitymeasurement,UV-vis-NIR spectroscopy,infrared resonance,single-crystal X-ray diffraction study.Compound 2 was also characterized by ⁵⁷Fe M?ssbauer spectroscopy.2.Reactivity of Fe?0?,Co?0?complexes coordinated by NHC and Styrene.Zero-valent iron-styrene complex 1 reacts with 2,6-dimethylphenylisocyanide to form an isocyanide-coordinated metal complex [?IPr?Fe?CNCy?4]?6?.Its reaction with one equivalent of vinyltrimethylsilyl produced a mixture of [?IPr?Fe??²-CH₂CHPh?₂]?1?and [?IPr?Fe??²-CH₂CHSiMe₃?₂]?8?.The zero-valent iron-styrene complex 2 reacts with two equivalents of 2,6-diisopropylphenyl azide to form the iron bisimide complex [?IMes?Fe?NDipp?2]?9?.The zero-valent cobalt-styrene complex 3 reacts with 2,6-diisopropylphenyl azide produced the cobalt bisimide complex [?IMes?Co?NDipp?₂]?10?.