Self‐Assembly of Cyclohelicate [M<sub>3</sub>L<sub>3</sub>] Triangles Over [M<sub>4</sub>L<sub>4</sub>] Squares, Despite Near‐Linear Bis‐terdentate L and Octahedral M
Bibliographic record
Abstract
Abstract Self‐assembly of 1:1:2 M II (BF 4 ) 2 (M=Zn or Fe), pyrazine‐2,5‐dicarbaldehyde ( 1 ) and 2‐(2‐aminoethyl)pyridine gave trimetallic triangle architectures rather than the anticipated tetrametallic [2×2] squares. Options for the nontrivial synthesis of 1 are considered, and synthetic details provided for both preferred routes. Rare cyclohelicate triangle architectures are observed for the pair of structurally characterized yellow‐brown [Zn 3 L 3 ](BF 4 ) 6 and dark green [Fe 3 L 3 ](BF 4 ) 6 complexes of the neutral bis‐terdentate Schiff base L . In order to form these pyrazine‐edged triangles, the octahedral metal ions—with all 6 N‐donors provided by the terdentate binding pockets of two L —are located 0.4–0.5 Å out of the plane of the bridging pyrazines, towards the center of the triangle. Density functional theory calculations confirm that simple particle counting entropic arguments, which predict triangles over squares, are correct here, with the triangles shown to be energetically favored over the corresponding squares. However, importantly, DFT analysis of these and related triangle versus square systems also show that vibrational contributions to entropy dominate and may significantly influence the preferred architecture, such that simple particle counting cannot in general be reliably employed to predict the observed architecture.
Fetched live from OpenAlex and de-inverted. Abstracts are not stored in this database: the inverted indexes are 8.6 GB of the frame’s 9.3 GB of text, and the host has 13 GB free.
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 | 0.002 | 0.001 |
| Meta-epidemiology (narrow) | 0.002 | 0.002 |
| Meta-epidemiology (broad) | 0.002 | 0.001 |
| Bibliometrics | 0.000 | 0.000 |
| Science and technology studies | 0.002 | 0.001 |
| Scholarly communication | 0.002 | 0.001 |
| Open science | 0.003 | 0.002 |
| Research integrity | 0.001 | 0.003 |
| 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; both teacher heads agree on what is shown here.
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".