title: Computer-Aided Molecular Design of Bis-phosphine Oxide Lanthanide Extractants.
abstract: Computer-aided molecular design and high-throughput screening of viable host architectures can significantly reduce the efforts in the design of novel ligands for efficient extraction of rare earth elements. This paper presents a computational approach to the deliberate design of bis-phosphine oxide host architectures that are structurally organized for complexation of trivalent lanthanides. Molecule building software, HostDesigner, was interfaced with molecular mechanics software, PCModel, providing a tool for generating and screening millions of potential R2(O)P-link-P(O)R2 ligand geometries. The molecular mechanics ranking of ligand structures is consistent with both the solution-phase free energies of complexation obtained with density functional theory and the performance of known bis-phosphine oxide extractants. For the case where the link is -CH2-, evaluation of the ligand geometry provides the first characterization of a steric origin for the "anomalous aryl strengthening" effect. The design approach has identified a number of novel bis-phosphine oxide ligands that are better organized for lanthanide complexation than previously studied examples.
authors.affiliation: Chemical Sciences Division, Oak Ridge National Laboratory , 1 Bethel Valley Road, Oak Ridge, Tennessee 37831-6119, United States.
authors.forename: Billy W
authors.initials: BW
authors.lastname: McCann
authors.affiliation: Department of Chemistry and Ames Laboratory, Iowa State University , Ames, Iowa 50011-3111, United States.
authors.forename: Nuwan De
authors.initials: ND
authors.lastname: Silva
authors.affiliation: Department of Chemistry and Ames Laboratory, Iowa State University , Ames, Iowa 50011-3111, United States.
authors.forename: Theresa L
authors.initials: TL
authors.lastname: Windus
authors.affiliation: Department of Chemistry and Ames Laboratory, Iowa State University , Ames, Iowa 50011-3111, United States.
authors.forename: Mark S
authors.initials: MS
authors.lastname: Gordon
authors.affiliation: Chemical Sciences Division, Oak Ridge National Laboratory , 1 Bethel Valley Road, Oak Ridge, Tennessee 37831-6119, United States.
authors.forename: Bruce A
authors.initials: BA
authors.lastname: Moyer
authors.affiliation: Chemical Sciences Division, Oak Ridge National Laboratory , 1 Bethel Valley Road, Oak Ridge, Tennessee 37831-6119, United States.
authors.forename: Vyacheslav S
authors.initials: VS
authors.lastname: Bryantsev
authors.affiliation: Supramolecular Design Institute , 127 Chestnut Hill Road, Oak Ridge, Tennessee 37830-7185, United States.
authors.forename: Benjamin P
authors.initials: BP
authors.lastname: Hay