Chelation Kinetics of Bidentate Phosphine Ligands on Pentacoordinate Ruthenium Carbonyl Complexes
Bibliographic record
Abstract
Chelation kinetics of the complexes Ru(CO) 4 (η 1 -(P−P)) have been studied in heptane, where P−P = Ph 2 P(CH 2 ) n PPh 2 ( n = 1, 2, 3, or 4, i.e., dppm, dppe, dppp, or dppb), Ph 2 P(NMe)PPh 2 (dppma), Ph 2 P( o -C 6 H 4 )PPh 2 (dpp-benzene), or R 2 P(CH 2 ) 2 PR 2 (R = Me or Cy, i.e., dmpe or dcpe). The complexes were prepared in situ by reaction of the bidentate ligands with Ru(CO) 4 (C 2 H 4 ), which itself was prepared in situ by photolysis of Ru 3 (CO) 12 under C 2 H 4 . The initially formed Ru(CO) 4 (η 1 -(P−P)) complexes react cleanly to form axial−equatorial Ru(CO) 3 (η 2 -(P−P)), as shown by the crystallographic structures of the products when P−P = dppe, dmpe, and dpp-benzene and the close similarity of their FTIR spectra to those of the other products. The chelated products undergo further reaction in solution or the solid state, and the product when P−P = dppma has been characterized by crystallography as Ru 2 (CO) 3 (μ-PPh 2 )(μ-Ph 2 PNMePPh 2 ). The kinetics of the displacement of CO from Ru(CO) 4 (η 1 -(P−P)) in n -heptane are characterized by Δ H ⧧ values that are lower by up to 9 kcal mol - 1 than those of their monodentate P-donor analogues. Δ S ⧧ values range from quite positive to slightly negative and suggest a trend from purely dissociative to appreciably associative mechanisms along the series P−P = dpp-benzene < dcpe < dmpe < dppp ≤ dppm ≈ dppbu ≈ dppe ≪ dppma. This contrasts with the CO-dissociative reactions of analogous Ru(CO) 4 L complexes when L = monodentate P-donor ligands.
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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 | 0.001 |
| 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) | 0.118 | 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".