Can Methyl Isobutyl Ketone Replace the Ionic Liquid in Selective Nd₂O₃ Dissolution from Nd₂O₃/Pr₆O₁₁ Mixtures? A Falsifiable Hypothesis and a Full Account of Its AI-Assisted Derivation

No experimental results are reported in this article. What is reported is a hypothesis, the reasoning that produced it, the specific reasons it may be wrong, an experimental programme capable of falsifying it, and a complete account of how generative artificial intelligence was used to derive it, including the errors those systems made. A programme from the Bhabha Atomic Research Centre, running from 2024, separates neodymium from praseodymium by selectively dissolving Nd₂O₃ out of a thermally conditioned physical mixture of Nd₂O₃ and Pr₆O₁₁, using a fluorinated β-diketone dissolved in an imidazolium bis(trifluoromethylsulfonyl)imide ionic liquid. Across five publications five fluorinated β-diketones have been examined, and secondary discussion indicates the imidazolium cation has also been varied within that family. Every reported dissolution medium located in this search is nonetheless an imidazolium bis(triflimide) ionic liquid; no test has been published in which the bulk phase is replaced by a conventional molecular organic solvent. The hypothesis advanced here is that the bulk ionic liquid may be replaceable by methyl isobutyl ketone, a commodity ketone already used in multistage mixer-settler extraction service and already named as a solvent in rare earth extraction patents, with the ligand and every other condition held constant. In the course of preparing this article I re-read the published supporting information and found a result that reframes the hypothesis. With unsintered oxides, the same ionic liquid and the same 0.1 M 2-thenoyltrifluoroacetone give a separation factor of 1.98 to 2.07 over one to four hours — comparable in magnitude to conventional solvent extraction, although the two quantities are defined differently. After sintering at 900 °C the same medium gives approximately 46. Thermal conditioning is therefore essential to the high selectivity observed under the reported conditions. The data do not show that the liquid plays no part — the selectivity may arise from the interaction between a conditioned surface and the liquid chemistry — but they do show that the liquid alone does not produce it. The sharper form of the hypothesis is therefore whether methyl isobutyl ketone can sustain the selectivity that appears when the liquid meets a thermally conditioned solid. The dielectric argument that originally motivated the choice of solvent is stated here with its correct provenance and is expressly described as a screening heuristic rather than evidence: the relative permittivity of 11 used to represent an imidazolium bis(triflimide) medium appears in a different study, on a different ionic liquid, with a different ligand class, while the selective-dissolution work used periodic density-functional calculations with no continuum dielectric at all. Seven mechanistic reasons the substitution may fail are set out, together with a nine-experiment falsification programme, the stoichiometric ceiling on solids loading, and a decision tree assigning a conclusion to each possible outcome. The final sections are a methodological record rather than a chemical one. They describe how an author with no laboratory and no formal training in chemistry produced this hypothesis through iterative dialogue with large language models, and they log thirteen specific errors those systems made — a fabricated patent application number, a federal solicitation deadline welded onto a programme that had closed three years earlier, a misattributed computational parameter, an experimental design that changed two variables at once in a system where one of them moves the answer fourteenfold, and proposed operating conditions exceeding the ligand stoichiometric ceiling by a factor of eighteen — together with how each was caught. United States Provisional Patent Application No. 64/178,827, covering aspects of the process, was filed by the author before this article was posted; the hypothesis and experimental programme are nonetheless set out here in full so that they can be tested.