Comprehensive DFT calculations on protonated metallic hexa halide anions MX6−(M=Ni, Pd, Pt; X=F, Cl)

• Published in: Journal of the Indian Chemical Society Vol. 98; no. 4
• Main Authors: Anoop Kumar, Pandey, Shukla, D.V, Vijay, Singh, Vijay Narayan, Mishra, Apoorva, Dwivedi
• Format: Journal Article
• Language: English
• Published: Elsevier B.V 01.04.2021
• Subjects: DFT; Electronic properties; Superacid; Superhalogen; V.D.E; Superhalogen; Superacid; Electronic properties; V.D.E; DFT
• ISSN: 0019-4522
• DOI: 10.1016/j.jics.2021.100046

We propose a new series of superacids by protonation of hexa-halide anions MX6−(M ​= ​Ni, Pd, Pt & X ​= ​F, Cl) by using combination of DFT/B3LYP method and SDD basis set. The strength of superacid is calculated by their Gibbs free energies of deprotonation. The acidity of these superacids is not only related to electronic stability of corresponding metallic anions MX6− but also on topology of protonated metallic anions. We have noticed that these base anions have very high vertical detachment energy (VDE), which indicates that they belong to superhalogenic family. A rough correlation (R2 ​= ​0.62) is found in between VDE of MX6−and acidity of protonatedMX6−. The AIM analyses of HMX6 help to understand its superacidic behaviour. Some electronic parameters of HMX6 are also calculated by using same level theory. We have also discussed the optimized structure of NiF6Li supersalt. The HOMO LUMO plots are used to describe chemical reactivity as well as the binding nature of HMX6 superacids and LiNiF6 salt. A new series of superacids have been proposed by protonation of hexa-halide anions MX6-(M ​= ​Ni, Pd, Pt X ​= ​F,Cl) by using DFT/B3LYP method with SDD for M and 6–311 ​+ ​G (d) basis sets for H, Cl, and F atoms. The acidity of these superacids has been investigated which depends on the electronic stability of their corresponding metallic anions (MX6-) as well as the topology of their protonated counterparts. It has been noticed that these base anions have very high vertical detachment energy (VDE), which indicates that they belong to superhalogenic family. The AIM analyses of HMX6 have been studied to understand their super acidic behaviour. Some electronic parameters of HMX6 are also calculated using same level theory. Also the optimized structure of new super salt (NiF6Li) has been discussed. The HOMO LUMO plots are used to describe chemical reactivity as well as the binding nature of HMX6 super acids and corresponding LiNiF6 salt. [Display omitted] •The superacidic behaviour of HMX6 is explored [where M= Ni, Pd, Pt] by using the combination of DFT-B3LYP/SDD basis set.•The calculated deprotonation energies show that all species belong to the family of superacids.•AIM analysis shows that acidity of HMX6 ​not only depends on VDE of their conjugate base anions but also topology of HMX6.•In LiNiF6, AIM analysis shows that all the three interactions in between Li8 ​and F3/F4/F5 ​are electrovalent in nature.