Bibliographic record
Abstract
[161337-67-3] C4F12HfO12S4 (MW 774.77) InChI = 1S/4CHF3O3S.Hf/c4*2-1(3,4)8(5,6)7;/h4*(H,5,6,7);/q;;;;+4/p-4 InChIKey = BQYMOILRPDTPPJ-UHFFFAOYSA-J (reagent used as Lewis acid in a wide array of reactions) Alternate Names: hafnium(IV) triflate; trifluoromethanesulfonic acid hafnium(IV) salt. Physical Data: mp >300 °C.1, 2 Solubility: sol in CH3CN, CH2Cl2, (CH2Cl)2, CH3NO2, dioxane, THF, toluene. Form Supplied in: white powder. Commercially available. Hafnium is routinely found with a low level of zirconium, since separation of the two elements is difficult. Analysis of Reagent Purity: IR(KBr),13C NMR, elemental analysis.1, 2 Preparative Methods: trifluoromethanesulfonic acid (22.1 mL, 250 mmol) was added to hafnium tetrachloride (8.61 g, 26.9 mmol) and the mixture was heated at 50 °C for 68 h under argon. The excess trifluoromethanesulfonic acid was removed and the residue was washed with petroleum ether. The obtained white powder was dried for 8 h (100 °C/0.5 mmHg) to give Hf(OTf)4 (20.9 g, 100%).1, 2 Handling, Storage, and Precautions: stable under recommended storage conditions. Hygroscopic. Keep container tightly closed in a dry and well-ventilated place. Irritating to eyes, respiratory system, and skin. Wear suitable gloves. Use in a fume hood.
Fetched live from OpenAlex and de-inverted. Abstracts are not stored in this database: the inverted indexes are 8.6 GB of the frame’s 9.3 GB of text, and the host has 13 GB free.
How this classification was reachedexpand
Full frame machine prediction
Teacher imitationNot calibrated prevalence, not ground truth. Human validation pending. The Gemma side is a direct model label for every work in the frame, read from the title-only record. The Codex side is a classifier learned from the 10,348 direct Codex labels and calibrated to design-weighted sample rates; fields without enough sample support carry no Codex call. Candidate is the union of the two sides; consensus is their intersection. These outputs are machine_predicted_unvalidated and are not human labels.
Distilled classifier scores by category (both heads)
| Category | Codex | Gemma |
|---|---|---|
| Metaresearch | 0.000 | 0.000 |
| Meta-epidemiology (narrow) | 0.001 | 0.000 |
| Meta-epidemiology (broad) | 0.001 | 0.000 |
| Bibliometrics | 0.000 | 0.001 |
| Science and technology studies | 0.001 | 0.000 |
| Scholarly communication | 0.000 | 0.000 |
| Open science | 0.001 | 0.001 |
| Research integrity | 0.001 | 0.001 |
| Insufficient payload (model declined to judge) | 0.015 | 0.011 |
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 source (direct Gemma or distilled Codex), 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".