Theoretical Study Of The Regulation Of The Electronic Properties Of Organic Molecules By Superhalogens

The dissertation can be divided into four chapters. The first chapter mainly introduces background knowledge. The utilized theoretical methods are demonstrated in the second chapter. The last part mainly includes the detailed research content, namely the regulation of the electronic properties of organic molecules induced by superhalogens. The last part includes two chapters:the regulation of the electronic properties of hydrocarbon molecules induced by superhalogens ?the third chapter? and the regulation of the electronic properties of amino acids molecules induced by superhalogens?the fourth chapter?, respectively.In the first chapter, we introduce the concept of superhalogens, development and application prospect. Finally it also introduces the research significance regulation the electronic properties of organic molecules induced by superhalogens.The second chapter describes ab initio methods used in the dissertation, including Hartree-Fock method, Coupled Cluster theory, Many-body perturbation theory and Outer Valence Green Function method.In the third chapter, we present the regulation the electronic properties of hydrocarbon molecules induced by superhalogens. We report here theoretical study of a series of composite structures of VDEs formed by mononuclear ?MgF₃^-, MgCl₃^-? and binuclear ?Mg₂F₅^-, Mg₂Cl₅^-? superhalogens combined with typical hydrocarbons i.e., ethylene, ethane and benzene, based on high-level ab initio calculations. At CCSD?T? level, compared with the mononuclear superhalogen composites, the VDE values of binuclear composites are higher. Therefore, polynuclear superhalogens are clearly more effective in regulating the electronic properties of typical organic small molecules. However, this more effective regulation is not only determined by superhalogen themselves but also related with the distribution of the extra electron of the composites. The relative order of VDEs with MP2 is generally consistent with CCSD?T?, knowing the extremely high cost of CCSD?T? calculations, MP2 method should be at least acceptable in the relative values of VDE.The fourth chapter describes the regulation the electronic properties of amino acids molecules induced by superhalogens. We report here theoretical study of a series of composite structures of VDEs formed by mononuclear ?MgF₃^-? and binuclear ?Mg₂F₅^-? superhalogens combined with typical amino acids i.e., cysteine, based on high-level ab initio calculations. According to previous conclusion, the comparison between HOMO and the extra electron distribution is performed in this system. We found that the distribution of HOMO is generally consistent with that of the extra electron, so the OVGF method could provide results as accurate as CCSD?T?. According to previous works, the underestimations of VDE by HF may be due to the lacking of electron correlation. The overestimations of VDE by MP2 may be resulted from the overcounting of the effect of electron correlation., the average VDE values of HF and MP2 are close to CCSD?T? results. So we also calculate the average VDE values of HF and MP2 here, we found that the average VDE values of those are close to OVGF results. At OVGF level, compared with the mononuclear superhalogen compositesCysMgF₂^-, the VDE values of binuclear composites CysMg₂F₄^- are higher. Therefore, polynuclear superhalogens are clearly more effective in regulating the electronic properties of typical amino acids molecules. This more effective regulation is determined by superhalogen themselves, because the extra electron of the composites aggregate on the cysteine moiety.