Self‐Assembled Multimetallic/Peptide Complexes: Structures and Unimolecular Reactions of [M<sub><i>n</i></sub>(GlyGly−H)<sub>2<i>n</i>−1</sub>]<sup>+</sup> and M<sub><i>n</i>+1</sub>(GlyGly−H<sub>2<i>n</i></sub>]<sup>2+</sup> Clusters in the Gas Phase
Bibliographic record
Abstract
The unimolecular chemistry and structures of self-assembled complexes containing multiple alkaline-earth-metal dications and deprotonated GlyGly ligands are investigated. Singly and doubly charged ions [Mn (GlyGly-H)n-1 ](+) (n=2-4), [Mn+1 (GlyGly-H)2n ](2+) (n=2,4,6), and [M(GlyGly-H)GlyGly](+) were observed. The losses of 132 Da (GlyGly) and 57 Da (determined to be aminoketene) were the major dissociation pathways for singly charged ions. Doubly charged Mg(2+) clusters mainly lost GlyGly, whereas those containing Ca(2+) or Sr(2+) also underwent charge separation. Except for charge separation, no loss of metal cations was observed. Infrared multiple photon dissociation spectra were the most consistent with the computed IR spectra for the lowest energy structures, in which deprotonation occurs at the carboxyl acid groups and all amide and carboxylate oxygen atoms are complexed to the metal cations. The N-H stretch band, observed at 3350 cm(-1) , is indicative of hydrogen bonding between the amine nitrogen atoms and the amide hydrogen atom. This study represents the first into large self-assembled multimetallic complexes bound by peptide ligands.
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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".