A DFT Prediction Study of Dibutyl Dithiophosphate Isomers as Extractant for Rare Earth Elements

Abstract

In this work, based on the DFT approach, the electronic structural properties of dibutyl dithiophosphate (DBDTP) and its isomers (sec-butyl dithiophosphate and tert-butyl dithiophosphate) as extracants for the separation of rare earth elements at the DFT level B3LYP/6 -31G(d) were predicted and also to ascertain the DBDTP ligand isomer’s conformation as well as their relative stability. Using the base function 6-31G*, the chemical reactivity was computed with the help of chemical hardness descriptors, electronic chemical potential and electrophilicity. It was found that sec.-BDTP has biggest energy gap, while tert.-BDTP exhibited the smallest energy gap. Thus, tert.-BDTP is the most chemically reactive and stable isomer, suggesting that the rare earth metal complexes with tert.-BDTP ligand is more stable.