Synthesis And Characterization Of Metallacycles Using O-alkynylphenyl Alkynes As Organic Source

Transition metalla-aromatics has drawn attention to more and more experimentalists and theoreticians.Throughout the history and development of transition metalla-aromatics,specifically,a series of metalla-aromatics that contained oxygen,nitrogen and sulfur atom are very common in transition metalla-aromatics.However,it is never reported the transition metalla-aromatics that contained halogen.Therefore,we aim to develop a method that can construct a series of metallachlorophenium aromatic complexes[LnMCl(ClR)]in this dissertation.Recently,metallacycles that showed Mobius aromaticity,spiro-aromaticity or σ-aromaticity were also revealed.The unsaturated systems of metallacycles that showedσ-aromaticity are rare.Only two examples that contained a fused σ-aromatic metallacyclopropene unit were reported.Herein,we report that the isolation of the first cyclopropaosmanaphthalenes that contained a σ-aromatic metallacyclopropene unit.The five chapters of this dissertation are shown as following:In the first chapter,the background of our research was briefly introduced,including the classification and criteria of aromaticity and transition metalla-aromatics.In addition,we describe the ideas and purposes of this dissertation in the final section of the chapter.In the second chapter,the synthetic method of osmachlorophenium complexes has been demonstrated.The first example of such complexes was isolated during our investigation of the reactivity of OsCl2(PPh3)3 with o-ethynylphenyl alkynes,which has the M-ClR bond being shorter than the M-Cl bond.We studied the reaction mechanism by deuteration experiment and the DFT calculation.Our reaction provides a new reaction pathway of electrophilic cyclization which compares the reactions of o-ethynylphenyl alkynes mediated by other transition.In addition,the theoretical calculations of nuclear independent chemical shift,isomerization stabilization energy and isotropic magnetic induction current density show that th e five-membered osmium-chlorocarbon ring has aromaticity.In the third chapter,the synthesis of ruthena-,rhoda-and irida-chlorophenium complexes has been studied.We expand the metal center of osmachlorophenium complex to ruthenium and iridium through the optimization of experimental conditions.Meanwhile,the five-membered metal-chlorocarbon ring has aromaticity by the DFT calculation.In this chapter,-we find that the reactivity of RhCl(PPh3)3 with the o-ethynylphenyl alkynes is a new chemistry.In the fourth chapter,the first cyclopropametallanaphthalene aromatics was produced from the reaction of OSCl2(PPh3)3 with o-cthynylphenyl alkynes in the presence of PPh3 and followed by the protonation of HCl.The DFT caclutions show that the cyclopropametallanaphthalene has two kinds of aromaticity including π-aromaticity and σ-aromaticity,in which the metallacyclopropene unit shows σ-aromaticity and the metallanaphthalene unit show s π-aromaticity.The summary is present in chapter 5.The innovation and the prospect of the research was also demonstrated.