Generation and dissociation of oxygen‐ and chloride‐bridged iron(III) and manganese(III) tetraphenylporphyrin dimer ions in the gas phase
Bibliographic record
Abstract
Electrospray ionization mass spectrometry (ESI/MS) has allowed the discovery of novel dimer ions emerging from solutions of metalloporphyrin salts and their investigation by collision-induced dissociation (CID) with N(2) molecules. ESI mass spectra have been recorded for the formation of the oxygen or chloride-bridged dimer ions [(FeTPP)(2)OH](+), [(MnTPP)(2)OH](+), [(FeTPP)(2)Cl](+) and [(MnTPP)(2)Cl](+) derived from various solutions of FeTPPCl and MnTPPCl salts. The CID of [(FeTPP)(2)OH](+) proceeds mainly by neutral loss of (FeTPP)OH to form [FeTPP](+) and, to a minor extent, to form the charge-reversed products. The CID of [(MnTPP)(2)OH](+) exhibits exclusively the product ion [MnTPP](+) by loss of neutral (MnTPP)OH. [(FeTPP)(2)Cl](+) and [(MnTPP)(2)Cl](+) dissociate by loss of (Fe/MnTPP)Cl to give rise to [Fe/MnTPP](+). [(FeTPP)(2)O](+) and [(FeTPP)(2)OH](+) were generated from a solution of the dimer, (FeTPP)(2)O. Dissociation of [(FeTPP)(2)O](+) yields two product ions, [FeTPP](+) and [(FeTPP)O](+), with higher onsets compared to the equivalent fragments formed from [(FeTPP)(2)OH](+).
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How this classification was reachedexpand
Full frame machine prediction
Teacher imitationNot calibrated prevalence, not ground truth. Human validation pending. The Gemma side is a direct model label for every work in the frame, read from the title-only record. The Codex side is a classifier learned from the 10,348 direct Codex labels and calibrated to design-weighted sample rates; fields without enough sample support carry no Codex call. Candidate is the union of the two sides; consensus is their intersection. These outputs are machine_predicted_unvalidated and are not human labels.
Distilled classifier scores by category (both heads)
| 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 | 0.000 |
| 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 source (direct Gemma or distilled Codex), 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".