Theoretical search for potential candidates as building blocks of hyperhalogens: BS2 and CrO4 molecules

Abstract

Previous works have shown that hyperhalogens can be created by changing the building blocks from halogens to superhalogens, e.g. hyperhalogens (Cu(BO2)2, Na(BO2)2 and Au(BO2)2) are created by replacing halogens of superhalogens MX2 (M = Cu, Na and Au; X = F, Cl and Br) with the superhalogen BO2, which has a higher electron affinity of 4.46 eV. Thus we explore the possibility of creating new hyperhalogens by using BS2 and CrO4 as building blocks. Our results show that although both BS2 and CrO4 are superhalogens, just as BO2 is, among their dimers only (CrO4)2 is a superhalogen, while (BS2)2 is not. When a Au atom is decorated with BO2, BS2 or CrO4, we found that Au(BO2)2 and Au(BS2)2 clusters can be termed hyperhalogens as their respective EA is larger than their corresponding building block BO2 and BS2, while Au(CrO4)2 is not. This is because the extra electron charge mostly goes to high electronegative BO2 and BS2 in anionic Au(BO2)2 and Au(BS2)2 clusters, while in anionic Au(CrO4)2 the extra charge is primarily located on the Au site. Moreover, the study of the interaction of superhalogen BS2 with Li or K atoms further confirms the ability of BS2 to act as a building block for hyperhalogens. The calculated fragmentation energies indicate that all of the clusters are stable against any fragmentation.