Reduction of Titanium Supported by a <i>σ</i>-/<i>π</i>-Bonded Tripyrrole Ligand: Ligand C−N Bond Cleavage and Coordination of Olefin and Arene with an Inverse Sandwich Structure
Bibliographic record
Abstract
The formally Ti(I)/Ti(II) mixed-valence toluene complex {2,5-[(C 4 H 3 N)CPh 2 ] 2 [C 4 H 2 N(Me)]}Ti ( μ, η 6 -C 7 H 8 )Ti[{2,5-[(C 4 H 3 N)CPh 2 ] 2 [C 4 H 2 N(Me)]}][K(DME) 2 ]·toluene ( 1 ) with an inverse sandwich type of structure has been obtained from the reduction of {2,5-[(C 4 H 3 N)CPh 2 ] 2 [C 4 H 2 N(Me)]}TiCl with potassium in toluene. The bridging molecule of toluene in the paramagnetic 1 shows a visible distortion due to a substantial amount of metal-to-ring back-bonding. Complex 1 was always the only detectable product, even in cases when lower than stoichiometric amounts of reductant were employed. DFT calculations have been carried out to elucidate the electronic structure of the mixed-valence 1 in order to clarify the reason for its apparent thermodynamic stability. The most energetically favorable model comprises two divalent Ti centers connected to an organic radical anion. The olefin adducts {2,5-[(C 4 H 3 N)CPh 2 ] 2 [C 4 H 2 N]}Ti( η 2 - trans- PhHC CHPh)[K(DME)] ( 2 ) and {2,5-[(C 4 H 3 N)CPh 2 ] 2 [C 4 H 2 N (Me)]}Ti( η 2 - trans -PhHC CHPh) ( 3 ) were obtained from identical reactions carried out in the presence of trans -stilbene. Complexes 2 and 3 may be regarded as the result of the oxidative addition of a transient divalent species to the trans -stilbene molecule. In the case of 2 however, the reaction is accompanied by the cleavage of the C−N bond of the π -bound alkylated pyrrole ring.
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 | 0.000 | 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) | 0.001 | 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".