Amphiphilicity of Tetraazaporphyrins Containing Four Terminal Carboxylic Acid and Four Alkyl Groups Promotes Face-on Orientation in Langmuir Films
Bibliographic record
Abstract
Control over the orientation of polycyclic aromatic dyes in thin films is paramount for tailoring their optical, electronic, and mechanical properties and reactivity. Their supramolecular assembly in deposited films is tuned here by converting the macrocyclic dyes into large amphiphilic structures. Octaalkythio-substituted tetraazaporphyrins (TAPs) with one carboxyalkyl and one alkyl chain per pyrrole ring were synthesized as statistical mixtures of four regioisomers. The unsymmetrically substituted maleodinitrile precursors were prepared in good yields with a flow reactor. All the tetra-ester precursor TAPs and the tetraacid TAPs do not show mesomorphism and instead display isotropic liquid phases at or close to room temperature. Interfacial properties of amphiphilic tetraacids were probed using Langmuir and Langmuir-Blodgett (LB) films. Langmuir films were generated on aqueous subphases at different pH values and characterized by surface pressure – molecular area isotherms, compressibility, Brewster angle microscopy, ellipsometry, and grazing incidence X-ray diffraction (GIXD). LB films transferred onto mica substrates were studied by atomic force microscopy (AFM). Reported is the dependence of the their LB properties on the spacer length, type of alkyl chain, and type of central metal. Also presented for comparison are diacid TAP compounds that preferentially give edge-on orientation.
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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".