Catalytic Synthesis, Characterization, and Properties of Polyaminoborane Homopolymers and Random Copolymers
Bibliographic record
Abstract
Polyaminoboranes, [RNH–BH2]n, are boron–nitrogen analogues of polyolefins: however, to date, few soluble, well-characterized examples have been described. Herein, we show that metal-catalyzed dehydrocoupling of N-alkylamine–boranes Ph(CH2)xNH2·BH3 (x = 2–4) with pendant aryl groups yields soluble polyaminoboranes [Ph(CH2)xNH–BH2]n, using skeletal nickel, [Rh(μ-Cl)(1,5-COD)]2 (COD = cyclooctadiene), and [IrH2(POCOP)] (POCOP = κ3-1,3-(OPtBu2)2C6H3) as precatalysts in THF. Application of the most efficient catalytic system (1 mol %, [IrH2(POCOP)], THF, −40 °C) enabled the isolation of high molar mass, soluble polyaminoborane [Ph(CH2)4NH–BH2]n in moderate (ca. 40%) yield. Structural characterization was achieved by multinuclear nuclear magnetic resonance, infrared, and elemental analysis; and the molar mass was determined to be high (Mn > 10 000 g mol–1) by gel permeation chromatography, dynamic light scattering, and, for comparison, also 1H diffusion-ordered spectroscopy methods. The optimized dehydropolymerization conditions for the Ir catalyst were also used to prepare copolymers from mixtures of Ph(CH2)4NH2·BH3 with either MeNH2·BH3, Ph(CH2)2NH2·BH3, or NH3·BH3. Significantly, soluble copolymers containing ca. 67% of [NH2–BH2] repeat units were prepared. The thermal stability of the polyaminoborane homopolymers and copolymers was studied by thermogravimetric analysis. The use of a cross-linker, H3B·NH2(CH2)8NH2·BH3, in the dehydropolymerization reactions led to improved ceramic yields after pyrolysis indicating that, with appropriate structural design, polyaminoboranes may be of potential future interest as precursors of boron-based ceramics.
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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) | 0.000 | 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) | 0.000 | 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".