Synthesis and characterization of N-silylated, <i> C</i><sub>1</sub><i>-</i>symmetric benzamidinates of lithium, sodium, and tin(II)
Bibliographic record
Abstract
The synthesis and characterization of complexes obtained from the reactions between Li[N-t-Bu(SiMe 3 )] (A) or the sodium analogue Na[N-t-Bu(SiMe 3 )] (B) and the cyanoarene RCN (R = Ph or 4-MeOC 6 H 4 ) are discussed. These are the THF adduct [Li{µ-cis-N(t-Bu)C(Ph)N(SiMe 3 )}(THF)] 2 (1), the TMEDA adduct Li[N(t-Bu)C(Ph)N(SiMe 3 )](TMEDA) (2), the neutral ligand-free lithium benzamidinate Li[N(t-Bu)C(C 6 H 4 OMe-4)N(SiMe 3 )] (3), and the THF adduct Li[N(t-Bu)C(C 6 H 4 OMe-4)N(SiMe 3 )](THF) (3a). The preparation and structure of the crystalline compound [Na{µ-cis-N(t-Bu)C(Ph)N(SiMe 3 )}(OEt 2 )] 2 (4) is described. From the lithium benzamidinate 1 and Sn(II) chloride the tin(II) complex [Sn{N(t-Bu)C(Ph)N(SiMe 3 )} 2 ] (5) was obtained. The molecular structures of the crystalline compounds 1, 4, and 5 were established by X-ray diffraction. In 1 and 4 the benzamidinato ligand is both chelating and bridging, with the Me 3 Si-substituted nitrogen atom as the bridging site. The central planar (MN) 2 four-membered ring is a rhombus in 1, with almost equal LiN bond lengths, whereas in 4 the bonds to Na(1) are significantly longer than those to Na(2). In 5, the ligand is N,N′-chelating. Key words: alkali metals, tin(II), benzamidinates, NMR spectra, X-ray structures.
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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 | 0.000 | 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 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".