Synthesis and X-ray structures of amidinate, oxoamidate, and thioamidate complexes of boron
Bibliographic record
Abstract
The reactions of PhBCl2 with Li[CE(NtBu)(nBu)] or Li[CS(NtBu)(NHtBu)] (1:1 molar ratio) in toluene at 23°C produced the heterocycles Ph(Cl)B(μ-NtBu)(μ-E)C(nBu) (1a, E = NtBu; 1b, E = O; 1c, E = S) or Ph(Cl)B(μ-NtBu)(μ-S)C(NHtBu) (2), which were characterized by 1H, 11B and 13C NMR and by mass spectra. X-ray structural determinations revealed that 1a, 1c and 2 contain four-membered rings. In 2 the thioamidate ligand adopts an N,S bonding mode. Crystal data: 1a, monoclinic, space group P21, a = 8.816(3), b = 11.311(2), c = 10.168(3) Å, β = 98.86(3)°, V = 1001.7(5) Å3, Z = 2, R = 0.042, and Rw = 0.020; 1c, monoclinic, space group P21/n, a = 7.617(2), b = 11.200(1), c = 19.568(2), β = 90.74(2)°, V = 1669.1(5) Å3, Z = 4, R = 0.046, and Rw = 0.059; 2, monoclinic, space group P21/a, a = 11.357(2), b = 12.289(2), c = 12.620(3) Å, β = 95.43(2)°, V = 1753.4(5) Å3, Z = 4, R = 0.043, and Rw = 0.027. Key words: boron, amidinate, oxoamidate, thioamidate, X-ray structures.
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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 | 0.001 | 0.000 |
| Research integrity | 0.000 | 0.000 |
| Insufficient payload (model declined to judge) | 0.002 | 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".