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 Me 3 Tl with a series of 2,(4),6‐substituted phenols in toluene or diethyl ether resulted in the formation of the species [Me 2 TlO(2,6‐R 2 C 6 H 3 )] 2 [R = H ( 4 ), Me ( 5 ), i Pr ( 6 ), Ph ( 7 )] and [Me 2 TlO(2,4,6‐ t Bu 3 C 6 H 2 )] ( 8 ). All compounds have been characterized by elemental analysis as well as their melting point; FTIR, FT‐Raman, solution 1 H and 13 C{ 1 H} NMR spectroscopy; and X‐ray crystallography. The structures of 4 – 7 are dimeric through short intermolecular Tl–O interactions, which yield a symmetric Tl 2 O 2 unit and a distorted seesaw C 2 O 2 bonding environment for thallium. An increase in the steric bulk in 4 – 6 has little effect on Tl–O bond lengths, whereas the C Me –Tl–C Me bond angle was found to significantly decrease. Further, the phenoxide ligands in 5 and 6 were found to be oriented perpendicular to the Tl 2 O 2 unit to minimize steric interactions. Alternatively, compound 7 shows an increase in Tl–O bond lengths and an increase in the C Me –Tl–C Me bond angle compared to 4 – 6 , and orientation of the phenoxide ligands perpendicular to the Tl 2 O 2 core. The significant steric bulk imposed by the –O(2,4,6‐ t Bu 3 C 6 H 2 ) ligand in 8 precludes dimer formation and allows for isolation of a monomeric species that contains a three‐coordinate T‐shaped C 2 O 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 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 | 0.000 | 0.000 |
| Meta-epidemiology (narrow) | 0.000 | 0.000 |
| Meta-epidemiology (broad) | 0.001 | 0.000 |
| Bibliometrics | 0.000 | 0.000 |
| Science and technology studies | 0.000 | 0.000 |
| Scholarly communication | 0.000 | 0.000 |
| Open science | 0.001 | 0.000 |
| Research integrity | 0.000 | 0.001 |
| Insufficient payload (model declined to judge) | 0.006 | 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 teacher head, 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".