Theoretical Study Of Rare Gas Compounds With Xenon(Radon) Double Bonds

The first rare gas compound appeared in 1962,and hundreds of rare gas compounds were successfully synthesized and theoretically predicted.It is worth noting that the current research on rare gas compounds is mainly concentrated on rare gas hydrides,rare gas fluorides,rare gas metal compounds,and mainly based on rare gas chemical single bonds.Previous studies have shown that heavy elements such as xenon and radon have higher chemical activities than other elements of the same family.Since they have empty d orbitals,can they form multi-bond compounds? In this paper,based on the previous work on the formation of double bond compounds between the transition metals Mo and W and the rare gas Xe,the bonding properties between As atoms with d orbit and Xe and Rn are further studied.This paper focuses on the structural properties of AsXeF₂ molecule and the structure was optimized at three levels: B3 LYP,BMK,and B2 PLYPD.AsXeF₂ is a planar molecule with C2 V symmetry.It is found that the As-Xe bond in the molecule is shorter than the standard single and double bonds.On this basis,the molecular orbital,bond order,ELF?electron localization function?and other analysis methods indicate that the As-Xe bond is a double bond.This article also analyzes the stability of the molecule and studies three possible decomposition pathways.Two of the decomposition pathways are endothermic reactions,and the AsXeF₂ molecule is thermodynamically stable relative to the two reaction products;the other decomposition pathway is an exothermic reaction.The results showed that the AsXeF₂ molecule and its isomer FAs Xe F were easy to isomerize.The energy barrier is 3.3kcal mol-1 at the B3 LYP level,and the energy barrier further decomposed into?Xe + As F2?is 24 kcal mol-1.In addition,in order to analyze the reaction energy barrier more accurately,this paper also used CCSD?T?to correct the TS energy under the structure of B3 LYP level.Based on the calculation of AsXeF₂ molecule,this paper also performed similar calculation and made an analysis on similar molecules PXeF₂,PXeF₂,PRnF₂.The analysis results show that PXeF₂,PXeF₂,and PRnF₂ molecules may also exist,and the As-Rn,P-Xe,and P-Rn bonds are all double bonds.