Kinetics and mechanism of the ring-opening copolymerization of CO2 and propylene oxide on a two-dimensional Co-Ni double metal cyanide complex
Bibliographic record
Abstract
The use of CO 2 as building block in organic chemistry is compelling due to its availability, cost-effectiveness, and potential to mitigate emissions while generating valuable, sustainable materials. Ring-opening copolymerization (ROCOP) of CO 2 and epoxides is a prime example of this. The viability of this technology, however, is highly dependent on the performance of the catalyst, and the Co-Ni DMC complex has recently demonstrated significant potential for industrial application. Thus, this article delves into the physicochemical characterization of this complex and offers a detailed examination of the kinetics and mechanism of CO 2 /PO ROCOP using in situ infrared spectroscopy. The behaviour of the catalyst is investigated under various operating conditions, including four different reaction temperatures, yielding an apparent activation energy of 59.8 kJ/mol. Zero-order kinetics with respect to CO 2 pressure and first-order kinetics with respect to PO concentration are observed, with minimal formation of cyclic by-products across all conditions. The influence of chloride ions and the role of chain-transfer agents on the complex are corroborated. Based on the characterization, kinetic, and mechanistic studies, a coordinative cationic copolymerization mechanism is proposed for the studied complex. • Co-Ni DMC for efficient CO 2 /PO ROCOP with no induction period and no PC formation • First-order kinetics with respect to PO and zero-order with respect to CO 2 • Thermodynamic analysis reveals moderate activation energy (59.8 kJ/mol) • Proposed insertion-coordination mechanism with PO ring-opening by OH - or TBA groups • Chain transfer studies confirm catalysts potential for immortal polymerization
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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) | 0.000 | 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) | 0.000 | 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".