Bridging Methylene to Bridging Acyl Conversion in Heterobinuclear Rh/Ru Complexes: Models for Adjacent-Metal Involvement in Bimetallic Catalysts
Bibliographic record
Abstract
Protonation of the methylene-bridged complex [RhRu(CO) 4 (μ-CH 2 )(dppm) 2 ][CF 3 SO 3 ] ( 1 ) at −80 °C yields an asymmetrically bridged methyl complex in which the methyl ligand is σ-bound to Ru while being involved in an agostic interaction with Rh. Warming to −40 °C results in migration of the methyl group to a terminal site on Rh, and further warming to 0 °C results in migratory insertion to give the acetyl-bridged complex [RhRu(OSO 2 CF 3 )(CO) 2 (μ-C(CH 3 )O)(μ-CO)(dppm) 2 ][CF 3 SO 3 ] ( 4 ), in which the acetyl carbon is bound to Rh and its oxygen is bound to Ru. At ambient temperature one carbonyl is lost from 4 to give [RhRu(OSO 2 CF 3 )(CO) 2 (μ-C(CH 3 )O)(dppm) 2 ][CF 3 SO 3 ] ( 5 ). Carbon-13 NMR spectroscopy and the X-ray structures of both acetyl-bridged products suggest significant carbene character in the acyl carbon. Attempts to obtain methyl and subsequently acetyl species by methylene insertion into metal−hydride bonds of the appropriate precursors [RhRu(X)(CO) 4 (μ-H)(dppm) 2 ][X] (X - = CF 3 SO 3 -, BF 4 - ) failed, with these hydride species being unreactive to CH 2 N 2 . Similarly, reaction of 1 with HCl yielded only the methyl complex [RhRu(CH 3 )(CO) 3 (μ-Cl)(dppm) 2 ][CF 3 SO 3 ], which did not undergo migratory insertion. Protonation of the methylene-bridged PMe 3 adduct [RhRu(PMe 3 )(CO) 3 (μ-CH 2 )(dppm) 2 ][CF 3 SO 3 ] yields [Rh Ru (OSO 2 CF 3 )(CO) 2 (μ- C (CH 3 )O)(dppm) 2 ][CF 3 SO 3 ] in which the binding of the acetyl group is reversed, being C-bound to Ru and O-bound to Rh. This species undergoes facile rearrangement to 5 at ambient temperature.
Fetched live from OpenAlex and de-inverted. Abstracts are not stored in this database: the inverted indexes are 8.6 GB of the frame’s 9.3 GB of text, and the host has 13 GB free.
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 | 0.001 | 0.000 |
| Meta-epidemiology (narrow) | 0.001 | 0.001 |
| Meta-epidemiology (broad) | 0.001 | 0.001 |
| Bibliometrics | 0.001 | 0.002 |
| Science and technology studies | 0.000 | 0.000 |
| Scholarly communication | 0.000 | 0.001 |
| Open science | 0.001 | 0.001 |
| 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 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".