Entrapment of <i>tert</i>-Butyllithium and Lithium <i>tert</i>-Butylamide Monomers by Partially Lithiated Derivatives of Aluminum and Gallium Primary Amide Complexes
Bibliographic record
Abstract
The lithiation of the dimeric trisamido group 13 derivatives {M[N(H) t -Bu] 3 } 2 ( 1a, M = Al; 1b, M = Ga) by alkyllithium reagents RLi (R = t -Bu or Me), at different stoichiometries, was investigated. On the basis of NMR data, the initial lithiation of 1a occurs at the bridging N(H) t -Bu groups to give the mono- and dilithiated derivatives Li x [Al 2 (N t -Bu) x (NH t -Bu) 6 - x ] ( x = 1, 2). The reaction of 1a with t -BuLi in a 1:3 molar ratio in n -pentane at 23 °C produces {Li[Al(N t -Bu)(NH t -Bu) 2 ]} 2 ·( t -BuLi) ( 2 ) in 67% yield, whereas the treatment of 1a with MeLi in diethyl ether at 23 °C yields {Li[Al(N t -Bu)(NH t -Bu) 2 ]} 2 ·[LiN(H) t -Bu] ( 7 ) and {Li[Al(N t -Bu)(NH t -Bu) 2 ]} 2 ( 8 ). The gallium analogue of 7, i.e., {Li[Ga(N t -Bu)(NH t -Bu) 2 ]} 2 ·[LiN(H) t -Bu] ( 5 ), was obtained in 47% yield by the reaction of 1b with t -BuLi in a 1:3 molar ratio in n -pentane at 23 °C. The structures of 2, 5, and 7 have been determined by X-ray crystallography and were shown to involve the entrapment of a monomeric t -BuLi or LiN(H) t -Bu fragment by a dilithiated derivative of 1a or 1b . The six fused four-membered rings give rise to a concave, lounge-chair arrangement for the 12-atom [Li 3 Al 2 N 6 E (E = C or N)] clusters of 2, 5, and 7 . Variable-temperature 1 H NMR spectra of 2, 5, and 7 in C 7 D 8 over the range −90 to 23 °C reveal a fluxional process involving Li−N bond breaking and formation.
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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".