Zeolite Activation of Organometallics: Anchoring and Decarbonylation Kinetics of Mo(CO)<sub>6</sub> in Dehydrated Na<sub>56</sub>Y Zeolite
Bibliographic record
Abstract
Quantitative temperature-dependent kinetic studies are reported of thermal reactions of Mo(CO) 6 that has been newly encapsulated in the α-cages of a Na 56 Y zeolite host. Under static vacuum, Mo(CO) 6 undergoes parallel anchoring and decarbonylation reactions, the latter yielding (OC) 3 Mo−Na 56 Y directly and the former resulting in the development of a characteristic six-band spectrum in the C−O stretching region. Kinetic and spectroscopic evidence was obtained for there being two different forms of (OC) 3 Mo−Na 56 Y. The activation parameters are unusual, with very low enthalpies and extremely negative entropies, viz. Δ H ⧧ = 40 ± 3 kJ mol - 1 and Δ S ⧧ = −185 ± 9 J K - 1 mol - 1 for anchoring and decarbonylation. This contrasts with the typically high enthalpic and positive entropic factors reported for corresponding CO dissociative reactions in xylene (Δ H ⧧ = 133 ± 6 kJ mol - 1 and Δ S ⧧ = +28 ± 16 J K - 1 mol - 1 ) or even the quite unusual values Δ H ⧧ = 61 ± 5 kJ mol - 1 and Δ S ⧧ = −139 ± 13 J K - 1 mol - 1 reported previously for 13 CO exchange in Mo(CO) 6 −Na 56 Y. It is concluded that the inner surface of Na 56 Y provides different activating environments for different reactions, behaving as multidentate anionic “zeolate” nucleophiles, with varying numbers of O 2 - ions participating in highly ordered transition states. A common intermediate, with three O 2 - ions participating in the anchoring and decarbonylation process, is proposed, one with two O 2 - ions being proposed for the 13 CO exchange reaction. The importance of temperature-dependent time-resolved infrared spectroscopy in elucidating such intimate mechanistic details is emphasized.
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) | 0.001 | 0.001 |
| Meta-epidemiology (broad) | 0.001 | 0.000 |
| Bibliometrics | 0.001 | 0.002 |
| 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) | 0.000 | 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".