A Joyful Journey: Tungsten(VI) and Tungsten(V) Fluorides Meet <i>N</i> ‐Heterocyclic Carbenes and Cyclic (Alkyl)(Amino)Carbenes
Bibliographic record
Abstract
Abstract The first complexation of tungsten(VI) fluoride with N ‐heterocyclic carbenes (NHCs) and a cyclic (alkyl)(amino) carbene (cAAC Me ) is reported, which led to formation of the complexes [(NHC)WF 6 ] (NHC = I i Pr Me , 1 ; BI i Pr, 2 ; IMes, 3 ; IDipp, 4 ; and SIDipp, 5 ) and [(cAAC Me )WF 6 ] 6 . Solid‐state structural analysis revealed distorted mono‐capped trigonal prismatic geometries for 2 and 3 , whereas 6 adopts a pentagonal bipyramidal coordination. Reduction of 1 – 6 with 0.5 equivalents of TMS‐pyr Me ‐TMS afforded rare tungsten(V) fluoride complexes [(NHC)WF 5 ] (NHC = I i Pr Me , 7 ; BI i Pr, 8 ; IMes, 9 ; IDipp, 10 ; and SIDipp, 11 ). Reduction of 6 with TMS‐pyr‐TMS yielded the dinuclear, fluoride‐bridged complex [(cAAC Me )WF 5 ] 2 12 . Subsequent addition of a second equivalent cAAC Me to 12 gave the mononuclear, seven‐coordinated bis‐carbene complex [(cAACMe) 2 WF 5 ] 13 . Magnetic susceptibility measurements and EPR spectroscopy confirm a predominantly metal‐centered d¹ radical in both 12 and 13 . These findings expand the scope of tungsten fluoride chemistry by providing rare examples of tungsten(VI) and tungsten(V) complexes stabilized by soft carbon‐donor ligands, paving the way for further exploration.
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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 | 0.002 | 0.002 |
| Meta-epidemiology (narrow) | 0.001 | 0.000 |
| Meta-epidemiology (broad) | 0.001 | 0.000 |
| Bibliometrics | 0.000 | 0.000 |
| Science and technology studies | 0.002 | 0.002 |
| Scholarly communication | 0.003 | 0.007 |
| Open science | 0.001 | 0.003 |
| Research integrity | 0.002 | 0.004 |
| Insufficient payload (model declined to judge) | 0.014 | 0.004 |
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".