Theoretical Study On Compounds Containing Rn-W Double Bonds

Rare gases have a fully filled outermost electronic configuration with very low chemical activity.Until 1962,British chemist Neil Bartlett synthesized the first rare gas compound Xe?PtF₆?_n?1?n?2?.This remarkable discovery has opened up a whole new field of chemistry research for rare gas compounds.However,most studies on the bonding of rare gases are currently involved in the formation of chemical single bonds,while the study of the formation of multiple bonds to rare gases is relatively rare.In addition,the rare gas transition metal compound breaks the chemical bond type of the s-p orbital between the rare gas and other atoms in the past,because the transition metal element contains a large number of d orbitals.Therefore,the p-d orbital bond between the rare gas and the transition metal is a major extension of the chemical bond field.The use of computational chemistry to explore new rare gas compounds provides a theoretical basis for synthetic experiments and promotes the synthesis and characterization of these new molecules,which will greatly enrich the types of compounds.This paper designs a novel compound formed by inserting rare gas atoms into transition metal fluorides.The structure,stability,vibration frequency,charge distribution and topological properties of the target compound X₂RnWX₂?X=F,Cl,Br?were calculated by B3LYP and MP2 quantum theory.It is found that the equilibrium geometry of the target molecule X₂RnWX₂?X=F,Cl,Br?has C_2V symmetry,and the predicted molecules calculated at the MP2 theoretical level have strong Rn-W bonds.The bond length values were 2.522,2.637,and 2.678?,respectively.Compared with the standard double bond length?2.65??of the Rn-W bond,the Rn-W bond in the target molecule is a chemical double bond.Molecular orbital analysis further clarifies the properties of the Rn-W bond and indicates that the double bond consists of a?bond and a?bond.In addition,a more precise coupling cluster theory method?CCSD?T??is used to correct the energy of the predicted compound F₂RnWF₂.Since each of the two-body decomposition reaction pathways of the compound has a sufficiently high energy barrier,indicating that the F₂RnWF₂ molecule has kinetic stability in the decomposition reaction,the result increases the possibility of synthesizing the compound in the low temperature isolation matrix condition.Under the MP2 theoretical level,the decomposition energy barriers of X₂RnWX₂?X=F,Cl,Br?are 10.2,6.1 and 9.6 kcal mol^-1,respectively,and the energy barrier heights of the compounds with their lowest overall energy values indicate the predicted molecule has thermodynamic stability.