Small bite-angle diphosphines — Synthesis and structure of low-valent complexes of bis(di-<i>ortho</i>-tolylphosphino)methane (dotpm) and related ligands
Bibliographic record
Abstract
The coordination chemistry of bis(di-ortho-tolylphosphino)methane (dotpm) has been studied. It is an excellent chelating ligand and a range of low-valent mononuclear complexes have been prepared; cis-[M(CO) 4 (η 2 -dotpm)] (M = Cr, Mo, W; 1–3), [CpRuCl(η 2 -dotpm)] (4), and cis-[MX 2 (η 2 -dotpm)] (M = Pt, X = Cl, Br, I; 5a–5c, M = Pd, X = Cl; 6). The backbone protons are relatively acidic and can be deprotonated using n-BuLi or LiN(SiMe 3 ) 2 . Subsequent alkylation by RX (X = halogen; R = Me, Et, CH 2 Ph) affords cis-[M(CO) 4 (η 2 -Rdotpm)] (M = Cr, Mo, W, R = Me; 7–9, M = Mo, W, R = Et, CH 2 Ph; 12–15), [CpRuCl(η 2 -Medotpm)] (10), and cis-[PtI 2 (η 2 -Medotpm)] (11). Thermolysis of cis-[Mo(CO) 4 (η 2 -Medotpm)] (8) yields what is believed to be the coordinately and electronically unsaturated complex [Mo(CO) 3 (η 2 -Medotpm)] (16), suggesting that derivatives of dotpm (cone angle 194°) are bulky enough to stabilize a 16-electron complex. Crystal structures of 2, 3, 7–9, 13, and 14 have been determined (diphosphine bite angles ranging from 66.58(3)° to 70.96(5)°.Key words: diphosphine, transition metal, bulky, carbonyl, ortho-tolyl.
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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 | 0.000 |
| 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 | 0.000 |
| Scholarly communication | 0.000 | 0.000 |
| Open science | 0.000 | 0.000 |
| Research integrity | 0.000 | 0.000 |
| Insufficient payload (model declined to judge) | 0.004 | 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".