Reactions of MAlH<sub>4</sub> (M = Li, Na) with primary amines — Synthetic and structural studies of alkali metal tetrakis(amido)aluminates and related dinuclear complexes
Bibliographic record
Abstract
The reactions of MAlH4 (M = Li, Na) with primary amines NH2R (R = t-Bu, i-Pr, p-tolyl) in a 1:4 molar ratio in THF produce the tetrakis(amido)aluminates, [M(THF)n][Al(NHR)4], in yields of 46%–82% together with secondary products. The extent of solvation of the alkali-metal cation varies from none (n = 0) for M[Al(NH-i-Pr)4] (2b, M = Li; 3b, M = Na) to n = 4 in the complex [Li(THF)4][Al(NH-p-tolyl)4] (2c), which exists as a solvent-separated ion pair. The complexes 2b, 3b, and [Na(THF)][Al(NH-p-tolyl)4]∞ (3c) all exhibit one-dimensional polymeric structures in which the bis-N,N′-chelating tetrakis(amido)aluminate anions are bridged by four- (2b, 3b) and five-coordinate (3c) metal ions, respectively. The structures of two of the secondary products, {[Na(THF)2][(NH-t-Bu)Al(H)(µ-N-t-Bu)]}2 (4) and {[Na(THF)3][(NH-p-tolyl)2Al(µ-N-p-tolyl)]}2 (5), were established by X-ray crystallography. Complex 4 is a dimer of the [HAl(NH-t-Bu)(N-t-Bu)]– anion, which forms a central Al2N2 ring with each monoanion N,N′-chelated to a [Na(THF)2]+ cation. Complex 5 is a dimer of the [Al(NR)(NHR)2]– (R = p-tolyl) anion in which the bridging p-tolyl groups are coordinated in an N-monodentate fashion to the trisolvated [Na(THF)3]+ cations. Key words: aluminohydrides, alkali metals, primary amines, tetrakis(amido)aluminates, structures.
Fetched live from OpenAlex and de-inverted. Abstracts are not stored in this database: the inverted indexes are 8.6 GB of the frame’s 9.3 GB of text, and the host has 13 GB free.
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".