Structural Effects of Varied Steric Bulk in 2,(4),6‐Substituted Dimethylthallium(III) Phenoxides
Bibliographic record
Abstract
Abstract The structural effects of varied steric bulk on 2,(4),6‐substituted dimethylthallium(III) phenoxides has been examined. The facile reaction of Me3Tl with a series of 2,(4),6‐substituted phenols in toluene or diethyl ether resulted in the formation of the species [Me2TlO(2,6‐R2C6H3)]2 [R = H (4), Me (5), iPr (6), Ph (7)] and [Me2TlO(2,4,6‐tBu3C6H2)] (8). All compounds have been characterized by elemental analysis as well as their melting point; FTIR, FT‐Raman, solution 1H and 13C{1H} NMR spectroscopy; and X‐ray crystallography. The structures of 4–7 are dimeric through short intermolecular Tl–O interactions, which yield a symmetric Tl2O2 unit and a distorted seesaw C2O2 bonding environment for thallium. An increase in the steric bulk in 4–6 has little effect on Tl–O bond lengths, whereas the CMe–Tl–CMe bond angle was found to significantly decrease. Further, the phenoxide ligands in 5 and 6 were found to be oriented perpendicular to the Tl2O2 unit to minimize steric interactions. Alternatively, compound 7 shows an increase in Tl–O bond lengths and an increase in the CMe–Tl–CMe bond angle compared to 4–6, and orientation of the phenoxide ligands perpendicular to the Tl2O2 core. The significant steric bulk imposed by the –O(2,4,6‐tBu3C6H2) ligand in 8 precludes dimer formation and allows for isolation of a monomeric species that contains a three‐coordinate T‐shaped C2O bonding environment for thallium. DFT calculations show that the energetic favorability of dimer formation decreases with increased phenoxide steric bulk.
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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".