Gas-Phase Conformations of Synthetic Polymers: Poly(ethylene glycol), Poly(propylene glycol), and Poly(tetramethylene glycol)
Why this work is in the frame
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Bibliographic record
Abstract
Effects of chain flexibility and cationizing agent on the gas-phase conformations of a series of polyethers were studied. Collision cross-sections of poly(propylene glycol) (PPG) and poly(tetramethylene glycol) (PTMEG) oligomers (from the 5-mer to 14-mer) cationized by sodium were measured using ion mobility methods and compared to earlier work on sodiated poly(ethylene glycol) (PEG). Molecular mechanics/dynamics calculations show that all three polyethers form a ring of oxygen atoms around Na +, coordinating additional oxygens to the cation from above and/or below this ring. However, the number and arrangement of these oxygens are system dependent. Up to 8 oxygens in PEG coordinate Na +, but that number drops to 7 for PPG and 6 for PTMEG. The difference is attributed to changes in the structural details of the ring as well as the position of the Na + ion in that ring. Molecular mechanics/dynamics calculations were also used to investigate the structures of neutral PPG and PTMEG oligomers. In these cases, the oligomers are relatively compact below 200 K but they suddenly unfold into more extended structures between 200 and 300 K.
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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 | 0.001 |
| Bibliometrics | 0.000 | 0.001 |
| Science and technology studies | 0.000 | 0.001 |
| Scholarly communication | 0.000 | 0.000 |
| Open science | 0.001 | 0.000 |
| Research integrity | 0.000 | 0.001 |
| Insufficient payload (model declined to judge) | 0.004 | 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 it