Synthesis Of Non-bridegehead Osmapentalenes And Theoretical Study Of Some Reactions And Aromaticity Of Metallapentalenes/Metallapentalynes

Fused-metallacycles have attracted wide attentions due to their unique properties of both transition metal complexes and organic fused rings.Our group has reported an unprecedent transition-metal-contained polycyclic framework,metallapentalynes in 2013.Since then,our group has developed the "Carbolong Chemistry" based on metallapentalenes and metallapentalynes as the key skeletons.The carbolong complexes have unique properties,such as unique aromaticity,good optical properties and diverse reactivities.Carbolong complexes play an important role in the development of the concept of aromaticity,and show potential applications in the filed of near-infrared materials,biomedical materials.In this dissertation,on the purpose of extending the "Carbolong Chemistry" of our group,we investigated the ligand substitution reactions of non-metal-bridgehead osmapentalenes.Besides,on the basis of the Density Functional Theory(DFT),we further studied some of the reaction mechanisms and related aromaticity involved the metallapentalenes and metallapentalynes.The main contents are showed as following:In chapter 1,the concept of aromaticity was briefly introduced.In addition,the chemistry of metallapentalenes and metallapentalynes was introduced.At last,the objectives and plans of this dissertation were presented.In chapter 2,as an extensive study of non-metal-bridgehead osmapentalene chemistry developed by our group,we investigated the ligand substitution reactions of these complexes.In addition,a new carbolong ligand was designed and synthesized in order to construct novel structures with potential applications.In chapter 3,in the view of the reactions of cyclcpropaosmapentalenes with substituted terminal alkynes,osmapentalyne with chalcogen electrophiles,and Simmons-Smith reactions of metallapentalynes,we took the density functional theory(DFT)to study the mechanisms of these reactions,which will improve the understanding of metallapentalenes and metallapentalynes on the theoretical level.In chapter 4,in light of a series of newly synthesized cyclopropametallapentalenes,osmaisoxazoles and aza-osmapentalenes by our group,we focused on the evaluation of the aromaticity in the skeletons of these carbolong complexes with the aid of density functional theory.In addition,an analysis of the electrophilic substitution sites of aza-osmapentalenes was also made by the theoretical calculations.This chapter improved the analysis of the aromaticity in the novel carbolong-based skeletons,and laided the foundation for future development and study of the properties of new structures.In chapter 5,the summary of this dissertation and the prospect of this work were presented.