Dimetallacycles from Monomeric 18-Electron M(CO)<sub>4</sub>(η<sup>1</sup>-C<sub>2</sub>H<sub>2</sub>) and M(CO)<sub>5</sub>(M = Ru, Os) Building Blocks: Synthesis and Mechanism of Formation
Bibliographic record
Abstract
The synthesis and spectroscopic characteristics of M(CO) 4 (η 2 -C 2 H 2 ) (M = Os, 1a; Ru, 1b ) are presented. The compounds readily react with the parent pentacarbonyls to yield the dimetallacyclic compounds Os 2 (CO) 8 (μ-C 2 H 2 ) ( 2 ) and MRu(CO) 8 (μ-C 2 H 2 CO) (M = Os, 3; Ru, 4 ). The structure of the compounds, based on IR and 13 C NMR spectroscopies, including extensive 13 C labeling, depends on the M(CO) 5 . Kinetic studies of the formation of 2 and 3 show that, in both cases, the reaction is slowed by the addition of free CO, but the inhibition is much greater with Os(CO) 5 . The initial step is dissociation of CO from Os(CO) 4 (η 2 -C 2 H 2 ), and the inhibition results from the competition between the reverse of this dissociation and reaction of the unsaturated intermediate with Os(CO) 5 or Ru(CO) 5 . With CO added to the system, subsequent steps in the condensation may become rate-limiting. Studies of the Ru(CO) 5 /Os(CO) 4 (η 2 -C 2 H 2 ) system with 13 CO-enriched reactants reveal further details about the course of the reaction.
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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 | 0.001 |
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".