title: Exploring electronic effects on the partitioning of actinides(iii) from lanthanides(iii) using functionalised bis-triazinyl phenanthroline ligands.
abstract: The first examples of 4,7-disubstituted 2,9-bis(5,5,8,8-tetramethyl-5,6,7,8-tetrahydro-1,2,4-benzo-triazin-3-yl)-1,10-phenanthroline (CyMe4-BTPhen) ligands are reported herein. Evaluating the kinetics, selectivity and stoichiometry of actinide(iii) and lanthanide(iii) radiotracer extractions has provided a mechanistic insight into the extraction process. For the first time, it has been demonstrated that metal ion extraction kinetics can be modulated by backbone functionalisation and a promising new CHON compliant candidate ligand with enhanced metal ion extraction kinetics has been identified. The effects of 4,7-functionalisation on the equilibrium metal ion distribution ratios are far more pronounced than those of 5,6-functionalisation. The complexation of Cm(iii) with two of the functionalised ligands was investigated by TRLFS and, at equilibrium, species of 1 : 2 [M : L] stoichiometry were observed exclusively. A direct correlation between the ELUMO-EHOMOenergy gap and metal ion extraction potential is reported, with DFT studies reaffirming experimental findings.
authors.affiliation: School of Chemistry, The University of Manchester, Oxford Road, Manchester, M13 9PL, UK. roger.whitehead@manchester.ac.uk.
authors.forename: Alyn C
authors.initials: AC
authors.lastname: Edwards
authors.affiliation: Karlsruher Institut für Technologie (KIT-INE), Institut für Nukleare Entsorgung, Hermann-von-Helmholtz-Platz 1, D-76344 Eggenstein-Leopoldshafen, Germany and University of Heidelberg, Department of Physical Chemistry, Im Neuenheimer Feld 253, 69120, Germany.
authors.forename: Christoph
authors.initials: C
authors.lastname: Wagner
authors.affiliation: Karlsruher Institut für Technologie (KIT-INE), Institut für Nukleare Entsorgung, Hermann-von-Helmholtz-Platz 1, D-76344 Eggenstein-Leopoldshafen, Germany.
authors.forename: Andreas
authors.initials: A
authors.lastname: Geist
authors.affiliation: School of Chemistry, The University of Manchester, Oxford Road, Manchester, M13 9PL, UK. roger.whitehead@manchester.ac.uk.
authors.forename: Neil A
authors.initials: NA
authors.lastname: Burton
authors.affiliation: School of Chemical Engineering, The University of Manchester, Oxford Road, Manchester, M13 9PL, UK.
authors.forename: Clint A
authors.initials: CA
authors.lastname: Sharrad
authors.affiliation: School of Chemistry, The University of Manchester, Oxford Road, Manchester, M13 9PL, UK. roger.whitehead@manchester.ac.uk.
authors.forename: Ralph W
authors.identifier: http://orcid.org/0000-0001-8009-5334
authors.initials: RW
authors.lastname: Adams
authors.affiliation: School of Chemistry, The University of Manchester, Oxford Road, Manchester, M13 9PL, UK. roger.whitehead@manchester.ac.uk.
authors.forename: Robin G
authors.initials: RG
authors.lastname: Pritchard
authors.affiliation: Karlsruher Institut für Technologie (KIT-INE), Institut für Nukleare Entsorgung, Hermann-von-Helmholtz-Platz 1, D-76344 Eggenstein-Leopoldshafen, Germany and University of Heidelberg, Department of Physical Chemistry, Im Neuenheimer Feld 253, 69120, Germany.
authors.forename: Petra J
authors.initials: PJ
authors.lastname: Panak
authors.affiliation: School of Chemistry, The University of Manchester, Oxford Road, Manchester, M13 9PL, UK. roger.whitehead@manchester.ac.uk.
authors.forename: Roger C
authors.initials: RC
authors.lastname: Whitehead
authors.affiliation: Department of Chemistry, The University of Reading, Reading, RG6 6AD, UK. l.m.harwood@reading.ac.uk.
authors.forename: Laurence M
authors.initials: LM
authors.lastname: Harwood