Synthesis and Ligand Properties of Chelating Bis( <i>N</i> -heterocyclic carbene)-Stabilized Bis(phosphinidenes)
Bibliographic record
Abstract
NHC–phosphinidene (NHCP) adducts are an emerging class of ligands with proven binding ability for main group and transition metal elements. They possess electron-rich P atoms with two lone pairs (LPs) of electrons, making them interesting platforms for the formation of multimetallic complexes. We describe herein a modular, high-yielding synthesis of bis(NHCP)s, starting from alkylidene-bridged bis(NHC)s ((IMe) 2 C n H 2n; n = 1,3) and triphosphirane (PDip) 3 (Dip = 2,6- i Pr 2 C 6 H 3 ) as phosphinidene transfer reagent. The coordination chemistry of [{DipP(IMe)} 2 CH 2 ], 1, was studied in detail, and complexes [ 1 ·FeBr 2 ] and [ 1 ·Rh(cod)]Cl were prepared, showing that the ligand has a flexible bite angle. The dicarbonyl complex [ 1 ·Rh(CO) 2 ]Cl, with an average value for the CO stretching frequency of 2029 cm –1, indicates a strongly donating ligand when compared to related complexes. The binding ability of the remaining two phosphorus LPs was demonstrated with AuCl(SMe 2 ), giving the heterotrimetallic complex [ 1 ·(AuCl) 2 ·Rh(cod)]Cl. Moreover, [ 1 ·Rh(cod)]X (X – = Cl, B(3,5-(CF 3 ) 2 -C 6 H 3 ) 4 ) was tested in the catalytic hydrogenation of methyl- Z -α-acetamidocinnamate (MAC) and dimethyl itaconate (ItMe 2 ), revealing that the chloride complex was inactive, while the BAr F complex demonstrated moderate activity. Additionally, [ 1 ·Rh(cod)]Cl was shown to be moderately air- and moisture-stable, slowly decomposing to the corresponding NHC-stabilized bis-dioxophosphorane, which was independently synthesized by treating the free ligand with dry O 2 .
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) | 0.001 | 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".