Unusual extraction of trivalent f-cations using diglycolamide dendrimers in a room temperature ionic liquid: extraction, spectroscopic and DFT studies

Seraj Ahmad Ansari; Prasanta Kumar Mohapatra; Andrea Leoncini; Sk Musharaf Ali; Ashish Singhadeb; Jurriaan Huskens; Willem Verboom

doi:10.1039/c7dt03831c

Unusual extraction of trivalent f-cations using diglycolamide dendrimers in a room temperature ionic liquid: extraction, spectroscopic and DFT studies

Dalton Trans. 2017 Dec 21;46(47):16541-16550. doi: 10.1039/c7dt03831c. Epub 2017 Nov 20.

Authors

Seraj Ahmad Ansari¹, Prasanta Kumar Mohapatra¹, Andrea Leoncini², Sk Musharaf Ali³, Ashish Singhadeb³, Jurriaan Huskens², Willem Verboom²

Affiliations

¹ Radiochemistry Division, Bhabha Atomic Research Centre, Trombay, Mumbai - 400 085, India. mpatra@barc.gov.in.
² Molecular Nanofabrication Group, MESA+ Institute for Nanotechnology, University of Twente, P.O. Box 217, 7500 AE Enschede, The Netherlands.
³ Chemical Engineering Division, Bhabha Atomic Research Centre, Trombay, Mumbai-400 085, India.

PMID: 29154386
DOI: 10.1039/c7dt03831c

Abstract

The complexation of Am³⁺ and Eu³⁺ was studied with three generations of diglycolamide (DGA)-functionalized poly(propylene imine) diaminobutane dendrimers (DGA-Den) with two, four and eight DGA moieties by solvent extraction and luminescence spectroscopy in a room temperature ionic liquid, viz. 3-butyl-1-methyl imidazolium bis(trifluoromethanesulfonyl)imide ([C₄mim][Tf₂N]). The extraction of trivalent f-cations was found to increase with decreasing HNO₃ concentrations conforming to a cation exchange mechanism with the extraction of Eu³⁺ being higher than that of Am³⁺ in the acid concentration range of 0.01-6.0 M HNO₃. The nature of the extracted species showed unusual trends compared to those reported previously in molecular diluents. Fluorescence lifetime data suggested the absence of H₂O in the extracted complexes meaning strong inner-sphere complexes. The nature of the extracted complexes predicted by solvent extraction was supported by DFT computations.