Polarization and Dipole Moment Effects on Sigma‐Hole Potential in Tin(IV)‐Porphyrins
Bibliographic record
Abstract
This study investigates how electron-withdrawing substitution, molecular polarization, and dipole moment influence the σ-hole potential in six-coordinate metalloporphyrins. To evaluate halogen bonding tendencies, we synthesized a series of five Sn(IV)-5,10,15,20-meso-tetrakis(4-iodophenyl)porphyrin complexes with various fluorinated phenolate axial ligands. Single-crystal X-ray diffraction analysis revealed distinct halogen-bonded supramolecular motifs, which vary depending on the degree of fluorination at the axial ligands. Our findings highlight the critical role of ligand-induced polarization and dipole moment variations in modulating the σ-hole characteristics of the equatorial iodine atoms. Computational modelling showed that increased fluorine substitution reduces both the atomic dipole moments of fluorine and the polarizability of the central tin ion. However, despite these changes, the axial fluorination has a negligible effect on the σ-hole potential at the iodine atoms. This limited influence is attributed to the orthogonal orientation between the porphyrin core and the peripheral phenyl rings, which suppresses resonance interactions. Overall, this work emphasizes the importance of understanding electronic effects at the molecular level, particularly in the design and formation of halogen-bonded supramolecular architectures.
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 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".