A Study On The Aromaticity Of Cyclazines,Fulvalenes And The Related Compounds

Aromaticity is one of the most basic and oldest concepts in organic chemistry.For nearly two hundred years,chemists have been devoted themselves to expansion of the conception of aromaticity,concentrated on expanding the types of aromatic compounds,engaged in the study of the universality of aromatic criteria.At present,aromaticity of organic compounds can be identified by experimental means and theoretical criteria.In this paper,topological resonance energy(TRE),which is belongs to the energy criterion,has been used.By TRE method,the global aromaticity of those compounds,suchasazaacepentalenes,perturbed[n]annulenes,doubly bridged[n]annulenes,fulvenes,fulvalenes and derivatives of calicene have been studied.The local aromaticity of the compounds has been calculated by BRE and CRE methods;furthermore,comparsion of CRE values and other aromatic criteria have also been done.The CC values of every non-identical circuit current of the above compound have been computed by CC method.The RC values of the corresponding compound were calculated from the CC values.We have also compared the consistency of the RC values and the ~1H-NMR data of the corresponding compound.This paper is composed of the following six chapters:The first chapter introduces the origin and development of aromaticity,several common aromaticity criteria have also been mentioned.Moreover,the aromatic criteria used in this paper,namely,TRE,%TRE,MRE,BRE,CRE,CC and RC methods have described in detail.Finally,the significance and purpose of this paper have been elaborated.In part 2,the main research object contains azaacepentalenes and corresponding derivatives.TRE,%TRE and MRE methods have been used to predicted the global aromaticity of those compounds,by using topological charge stability rule(TCS)to explain the aromatiocity of the related compounds.Then,the local aromaticity has been investigated by BRE and CRE methods,and the circuit current of the corresponding compounds has been predicted by CC method.Finally,the magnetic properties of those compounds have been studied by RC method,comparsion of RC results with ~1H-NMR data of corresponding compounds have also been done.In the third chapter,the study of the global aromaticity,local aromaticity and magnetic properties of perturbed[n]annulenes and its nitrogen-substituted derivatives have been done.According to the peripheral model theory proposed by Platt,the main source of aromaticity of the perturbed[n]annulenes is the peripheral ring or the small single-ring circuit,which is inferred to be proved.In addition to that,the results of TRE method have been compared with REPE calculations by Hess,relative hardness predictions by Robert.In chapter 4,the aromaticity of the doubly bridged[n]annulenes and its related derivatives has been mainly studied.Those derivatives have good application prospects in the fields of superconducting materials and semiconductor materials.The global aromaticity of these compounds has been analyzed by TRE and%TRE methods,and the local aromaticity has been investigated by BRE and CRE methods.The magnetic properties of the above compounds have been predicted by RC method.In chapter 5,it is mainly concerned with fulvenes and fulvalenes and their derivatives.In addition to fulvenes and fulvalenes,the aromaticity of benzofulvenes,benzofulvalenes and quinarenes have also been studied.The effect of benzene on the aromaticity of the fused products has been discussed.The effect of inserting a six-membered ring into the fulvalenes on the aromaticity of its derivatives quinarene has been discussed.In chapter 6,compounds composed by the substructure of calicene,such as bicalicene,bicyclic tercalicene,tricyclic tetracalicene and their ionic compounds are the main research objects.The global aromaticity of such compounds has been investigated by TRE and%TRE methods,and the order of the neural and ionic compounds was analyzed.The local aromaticity of the neutral and ionic compounds has been studied by BRE and CRE methods,and the contribution of the three-membered ring,five-membered ring and eight-membered ring to the global aromaticity of the molecule has also been analyzed.The magnetic properties of the neutral and ionic compounds have been predicted using the RC method and compared with the ~1H-NMR data of the synthesized compounds.