Dialkylscandium Complexes Supported by β-Diketiminato Ligands: Synthesis, Characterization, and Thermal Stability of a New Family of Organoscandium Complexes
Bibliographic record
Abstract
Several diorganoscandium complexes stabilized by the β-diketiminato ligands (Ar)NC(R)CHC(R)N(Ar) (Ar = 2,6- i Pr-C 6 H 3; R = CH 3 (ligand a ), R = t Bu (ligand b )) have been synthesized. Reaction of the lithium salts of the ligands with ScCl 3 ·3THF leads to the complexes LScCl 2 (THF) n, which may be readily alkylated to form the dialkyl derivatives. Most are isolated as base-free, four-coordinate complexes. Several have been characterized via X-ray crystallography, and a detailed discussion of their structures is presented. Steric interactions between Ar and the Sc−alkyl groups force the scandium to adopt an out-of-plane bonding mode. In solution, this is manifested via a fluxional process which equilibrates the two diastereotopic alkyl groups and ligand groups as well. The barriers to this process roughly correlate with the steric bulk of the alkyl substituents. At elevated temperatures, the dialkyl derivatives LScR 2 undergo a metalation process whereby one of the alkyl groups is eliminated as RH, and a ligand i Pr group is metalated in the methyl position. These reactions are first order in scandium complex, and activation parameters of Δ H ⧧ = 19.7(6) kcal mol - 1 and Δ S ⧧ = −17(2) cal mol - 1 K - 1 were measured for the loss of Me 4 Si from (Lig b )Sc(CH 2 SiMe 3 ) 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".