Synthesis and coordination chemistry of the diamido-arsine ligand [NAsN] (NAsN = PhAs(CH<sub>2</sub>SiMe<sub>2</sub>NPh)<sub>2</sub>))
Bibliographic record
Abstract
The preparation and characterization of the diamido-arsine ligand [NAsN]Li2(THF) (1) (where NAsN = PhAs(CH2SiMe2NPh)2), the protonated ligand precursor [NAsN]H2 (2), and its coordination chemistry with tantalum is presented. The complex [NAsN]TaMe3 (3) can be synthesized from 1 and TaMe3Cl2. Hydrogenation of 3 did not produce the desired tetrahydride ([NAsN]Ta)2(µ-H)4, instead, activation of Ta–N bonds in the complex produced a modest yield of the free ligand 2. In an attempt to understand the unusual reactivity of 3, a density functional theory investigation of the model complexes 'NAsN'Li2(OMe2)2 (4) and 'NAsN'TaMe3 (5) (where 'NAsN' = MeAs(CH2SiH2NMe)2) and their phosphine analogs 'NPN'Li2(OMe2) (7), 'NPN'TaMe3 (8), and a related niobium complex 'NPN'NbMe3 (10) (where 'NPN' = MeP(CH2SiH2NMe)2) was undertaken. The difference between the chemistry supported by the As and P ligands originates from the poor binding of As to Ta in these systems and is likely due to a mismatch of the soft As donor and the hard Ta(V) metal centre.Key words: arsine ligand, tridentate, tantalum, hydrogenation, DFT calculations.
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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 | 0.000 | 0.000 |
| Meta-epidemiology (narrow) | 0.000 | 0.000 |
| Meta-epidemiology (broad) | 0.000 | 0.000 |
| Bibliometrics | 0.000 | 0.000 |
| Science and technology studies | 0.000 | 0.000 |
| Scholarly communication | 0.000 | 0.000 |
| Open science | 0.000 | 0.000 |
| Research integrity | 0.000 | 0.000 |
| Insufficient payload (model declined to judge) | 0.002 | 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 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".