Syntheses, X-ray structures, and redox behaviour of the group 14 bis-boraamidinates M[PhB(μ- <i>N</i> - <i>t</i> -Bu) <sub>2</sub> ] <sub>2</sub> (M = Ge, Sn) and Li <sub>2</sub> M[PhB(μ- <i>N</i> - <i>t</i> -Bu) <sub>2</sub> ] <sub>2</sub> (M = Sn, Pb)
Bibliographic record
Abstract
The solid-state structures of the complexes M[PhB(μ-N-t-Bu) 2 ] 2 (1a, M= Ge; 1b, M = Sn) were determined to be spirocyclic with two orthogonal boraamidinate (bam) ligands N,N′-chelated to the group 14 centre. Oxidation of 1b with SO 2 Cl 2 afforded the thermally unstable, blue radical cation {Sn[PhB(μ-N-t-Bu) 2 ] 2 } •+ , identified by electron paramagnetic resonance (EPR) spectroscopy supported by density functional theory (DFT) calculations, whereas the germanium analogue 1a was inert towards SO 2 Cl 2 . The reaction between Li 2 [PhB(μ-N-t-Bu) 2 ] 2 and SnCl 2 or PbI 2 in 2:1 molar ratio in diethyl ether produced the novel heterotrimetallic complexes Li 2 Sn[PhB(μ-N-t-Bu) 2 ] 2 (2b) and (Et 2 O·Li)LiPb[PhB(μ-N-t-Bu) 2 ] 2 (2c·OEt 2 ), respectively. By contrast, treatment of Li 2 [PhB(μ-N-t-Bu) 2 ] 2 with C 4 H 8 O 2 ·GeCl 2 yielded the germanium(IV) complex 1a via a redox process. The X-ray structures of 2b and 2c·THF revealed polycyclic arrangements in which one bam ligand is N,N′-chelated to the Sn(II) or Pb(II) atom and one of the Li + cations, while the second bam ligand exhibits a unique bonding mode, bridging all three metal centres. The fluctional behaviour of 2b was investigated by variable temperature, multinuclear NMR spectroscopy.
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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) | 0.002 | 0.001 |
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".