Temperature dependence of conformation, chemical state, and metal-directed assembly of tetrapyridyl-porphyrin on Cu(111)
Bibliographic record
Abstract
We present a combined scanning tunneling microscopy (STM), near-edge x-ray-absorption fine-structure, and x-ray photoemission spectroscopy (XPS) study on the bonding and ordering of tetrapyridyl-porphyrin molecules on the Cu(111) surface in the 300-500 K temperature range. Following deposition at 300 K the molecules are adsorbed with a pronounced conformational adaptation of the anchored species featuring a saddle-shaped macrocycle and terminal groups pointing toward the substrate. Upon moderate annealing supramolecular chains evolve that are stabilized by metal-ligand interactions between the mesopyridyl substituents and copper adatoms resulting in twofold copper coordination. Annealing to temperatures exceeding 450 K strongly alters the molecular appearance in high-resolution STM data. This modification was also induced by controlled voltage pulses and related to a deprotonation of the molecule by XPS. Under appropriate conditions a novel binding motif leads to honeycomb structures coexisting with the chain segments. The conformation withstands annealing without large modification.
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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".