Theoretical Studies Of Novel Superhalogens/Hyperhalogens Species

By means of the quantum chemical methods and the atom-assembly strategies, wedesigned a serious novel superhalogen and hyperhalogen species, and studied theirelectron affinities and stabilities. It is not only helpful for researching novelexperience hyperhalogens and superhalogens, but also enriching hyperhalogen andsuperhalogen families. The summarized most important results of this paper are asfollows:1. In this paper, using superhalogen species, namely AuF4and PO3, as the modelbuilding blocks, we made the first attempt to assemble the Au,P-based hyperhalogenspecies, i.e., AuF_4-n（PO₃）_n （n=1-4）, at the B3LYP/6-311+G（d）/SDD andCCSD（T）/6-311+G（d）/SDD （single-point） levels（6-311+G（d） for O, F, P and SDD forAu）. Notably, all the designed Au,P species in the paper, dioxo-bonded structures arethe most stable isomers with n3. They are significantly more stable than the usuallypresumed isomers maintaining mon-oxo-bridge isomers. Meanwhile, when n3, theenergetically favored structures are isomers with clustering of the–PO₃moieties. Toour best knowledge, we first reported cage-like oxide hyperhalogen species, i.e., themost stable isomers of AuP4O120,. Thus, we can safely draw a conclusion that the PO3moiety, as building block, cannot be retained in the “bottom-up” assembly. Theground state of AuF₄-n（PO₃）n （n=1-4） possess the Vertical Detachment Energy（VDE） value, ranging from7.168.20eV, much higher than the VDE values of AuF4（7.08eV） and PO₃（4.69eV）, which are the corresponding building blocks. Also,these hyperhalogen species possess Adiabatic Detachment Energy （ADE） valuesexceeding6.00eV. We discussed possible generation routes for AuF₄-n（PO₃）n0,（n=1-4）, and suggested possible ways to synthesis them. These oxyfluoride species,we designed, not only enriches the family of hyperhalogens, but it also demonstratesthe great importance of taking the structural transformation into consideration duringthe superhaogen hyperhalogen design, as an example, for the present Au-P basedsystems. 2. The structures, electron affinity and thermodynamic stability of the compoundsXO₃^0,-, XO₂F₂^0,- and XOF₄^0,- containing the higher group-15elements X=P, As, Sb,Bi have been studied. Amongst, the results of AsO₂F₂, BiO₂F₂and BiOF₄representthe first report. It was shown that some oxyfluoride species, i.e., PO₂F₂（0,-），AsO₂F₂^0,-，POF₄^0,-，AsOF₄^0,-，SbOF₄^0,-，and BiOF₄^0,-, possess significantly higher EA values（VDE is around5.03-6.21eV and ADE is around4.60-5.48eV） than that of halogen（F，3.40eV；Cl，3.62eV）. Thus, we recommended that the oxyfluorides in form ofXO₂F₂^0,- and XOF₄^0,- should be potentially considered as a type of superhalogens,which have been ignored previously. The concept,“oxyfluoride superhalogen”, shouldenrich the superhalogen family. Yet, we also found that though BiO2F20, and BiO30, accord to the structural formula of the novel oxyfluoride and the traditional oxidesuperhaogens, respectively, both possess a high VDE yet a low ADE. This is inmarked contrast to the previously reported superhalogens, which generally containboth the high VDE and high ADE values. Thus, BiO2F20, and BiO30, should not beconsidered as superhalogens. BiO2F20, is the exception of the newly proposedoxyfluoride superhaoglen, while BiO30, is the first exception of traditional oxidesuperhalogen. The finding revealed that for the analogous main-group compoundswith the same structural formula, the difference in the metallic property of the coreelement could lead to the significant difference in the ground structures of either theanionic or neutral structures, which would result in the much differed superhalogenfeatures.