Zeolitic polyoxometalates metal organic frameworks (Z-POMOF) with imidazole ligands and ε-Keggin ions as building blocks; computational evaluation of hypothetical polymorphs and a synthesis approach
Bibliographic record
Abstract
We investigate here a new family of zeolitic Metal Organic Frameworks (MOFs) based on imidazole (im) as the ligand and epsilon-type Keggin PolyOxoMetalates (POMs) as building units. The POM used in this study is the epsilon-{PMo(12)O(40)} Keggin isomer capped by four Zn(ii) ions (noted epsilon-Zn) in tetrahedral coordination. We describe here our methods to first construct and then evaluate the stability of hypothetical 3-D POMOFs possessing a tetrahedral network, typified by dense silica polymorphs and zeotypes and referred here to as Z-POMOFs. We use the analogy between the connectivity of silicon ion in dense minerals or zeolites and the epsilon-Zn, using imidazolate ligands to mimic the role of oxygen atoms in zeolites. Handling the epsilon-Keggin and imidazole as the constitutive building-blocks, a selection of 40 polymorphs were constructed and their relative stabilities computed. Among these Z-POMOFs, the cristobalite-like and zni-structure were identified as the most stable candidates. In parallel, we have attempted to synthesize Z-POMOF structures with epsilon-Zn POMs, synthesized in situ under hydrothermal conditions, and imidazole ligands. We present our first experimental result, the extended material [NBu(4)][PMo(V)(8)Mo(VI)(4)O(37)(OH)(3)Zn(4)(im)(Him)], named epsilon(im)(2). The structure of the hybrid framework is built by the connection of dimerized epsilon-Zn POMs to imidazole ligands in two directions. The obtaining of the first POMOF based on imidazole ligand is an encouraging step towards the synthesis of a new family of POMOFs.
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How this classification was reachedexpand
Full frame distilled prediction
Teacher imitationNot calibrated prevalence, not ground truth. Human validation pending. Learned from the 10,348 direct Codex labels and 10,348 direct Gemma labels. Candidate is the union of thresholded teacher heads; consensus is their intersection. These outputs are machine_predicted_unvalidated and are not human labels or direct frontier model labels.
Codex and Gemma teacher scores by category
| Category | Codex | Gemma |
|---|---|---|
| Metaresearch | 0.000 | 0.001 |
| Meta-epidemiology (narrow) | 0.000 | 0.000 |
| Meta-epidemiology (broad) | 0.001 | 0.000 |
| Bibliometrics | 0.000 | 0.000 |
| Science and technology studies | 0.000 | 0.001 |
| Scholarly communication | 0.000 | 0.000 |
| Open science | 0.000 | 0.000 |
| Research integrity | 0.000 | 0.001 |
| Insufficient payload (model declined to judge) | 0.000 | 0.000 |
Machine scores (provisional)
The two teacher heads of the student model, read on this work. A score orders the frame for review; it never asserts a category, and the validation status ships verbatim with every row.
Baseline scores from an immature model (maturity gate not passed, 7 training rounds). Scores rank; they never assert a category.
score_only:v0-immature-baseline · verbatim from the scoring run: score_only means the number may rank works, and no category label ships from itClassification
machine, unvalidatedMachine predicted; a candidate call from one teacher head, not a consensus.
How this classification was reached, model by model and score by score, is at the end of the page under "How this classification was reached".