Journal article
Structural Analysis of Lanthanide-DOTAM Coordination Complexes and Use of Machine Learning to Rationally Design Molecular Recognition for Selective Rare Earth Recovery
Chemical science (Cambridge)
07/15/2026
DOI: 10.1039/D6SC03531K
Abstract
Rare earth elements (REE) are challenging for chemical separations because of similarities in charge and ionic radii. Developing materials with high metal specificity, such as molecularly imprinted polymers, could enhance selectivity, but there are limited details available to support the rational design of selective REE binding motifs. In the current study, structural characterization of REE-DOTAM (1,4,7,10-tetrakis(carbamoylmethyl)-1,4,7,10-tetraazacyclododecane) complexes were combined with density functional theory (DFT) and machine learning (ML) to provide specific structural descriptors that can be used to develop selective REE sites. Nineteen REE-DOTAM complexes were synthesized from mixed solvent systems (H2O/DMF, H2O/DMSO, H2O/DMA) and characterized using single-crystal X-ray diffraction. The resulting structural data were used to construct perfect templates (fixed ligand geometries without further relaxation) and relaxed templates (fully geometry-optimized structures). DFT-derived substitution energies revealed that selectivity between heavy and light REEs could be achieved, with larger energetic penalties observed for the perfect templates. Machine learning analysis attributed selectivity primarily to hydration energies in the perfect templates, with twist angles as the dominant structural controls in the relaxed systems. Additional analysis of the ML output suggested specific conditions that could be targeted for rationally designed DOTAM based materials for improved REE selectivity
Details
- Title: Subtitle
- Structural Analysis of Lanthanide-DOTAM Coordination Complexes and Use of Machine Learning to Rationally Design Molecular Recognition for Selective Rare Earth Recovery
- Creators
- Nicole Shapiro - University of IowaHarindu RajapakshaXiaohui QuSara E. MasonDavid Michael CwiertnyTori Z Forbes
- Resource Type
- Journal article
- Publication Details
- Chemical science (Cambridge)
- DOI
- 10.1039/D6SC03531K
- ISSN
- 2041-6520
- eISSN
- 2041-6539
- Publisher
- Royal Society of Chemistry
- Language
- English
- Electronic publication date
- 07/15/2026
- Academic Unit
- Center for Health Effects of Environmental Contamination; Civil and Environmental Engineering; Core Research Facilities; Chemistry; Chemical and Biochemical Engineering
- Record Identifier
- 9985183576002771
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