Study of the Reactivity of Osmapyridiniums and Osmanaphthalene

The chemistry of transition-metal-containing aromatic compounds is attracting increasing research interests because they show the aromaticity as well as the reactivities of organometallics.Till now,the research interests are mainly focused on the development of new synthetic method and the expanding scope of the aromatic metallacycles.In this thesis,the relatively less developed metallapyridine and metallanaphthalene were investigated.The two osmapyridiniums were synthesized by the hydride osmium carbyne and benzonitrile via the[4+2]cycloaddition reaction. And the reactivity of the osmapyridiniums was also investigated,affording another two osmapyridines and one osmapyridine.In addition,the reaction of osmanaphthalene with different kinds of ligands gave new osmanaphthalenes.The reaction between CO and the by-product of hydride osmium carbyne to give the osmium vinyl compound was also studied.This thesis contains five chapters.In chapter 1,the research background of the transition-metal-containing aromatic compound was reviewed.It is notable that the stable examples of metallanaphthalene and metallapyridine are very rare.In chapter 2,the[4+2]cycloaddition reaction between hydride alkenylcarbyne complex and benzonitrile was described,affording two osmapyridinium compounds 2-5 and 2-6.The reactivity of osmapyridinium 2-6 and 2-3 was also investigated, giving another two osmapyridinium 2-7 and 2-8 and one osmapyridine 2-9, respectively.In chapter 3,the reactivity of osmanaphthalene 3-1 was investigated.Two osmanaphthalene 3-2 and 3-3 were obtained from the reaction of osmanaphthalene 3-1 with phenanthroline and acetonitirle,respectively.In chapter 4,the reaction of CO and the unstable compound 4-1 was investigated, giving the osmium vinyl compound 4-2.In chapter 5,the innovation of this dissertation was summarized and the prospect of this research is presented.