Organotitanium Complexes Supported by a Dianionic Pentadentate Ligand
Bibliographic record
Abstract
The tetrapyralzolylpyridyl diborate pentadentate ligand B2Pz4Py has been complexed to Ti(III) to form the chloro complex (B2Pz4Py)Ti(III)Cl, which is a convenient starting material for preparing alkyl and hydride derivatives of this ligand. The former (R = CH3 and CH2SiMe3) are highly thermally stable and do not react with dihydrogen to form (B2Pz4Py)Ti(III)H. Rather, treatment of the chloro starting material with NaHBEt3 affords the desired hydrido complex in 85% yield. This Ti(III) hydride was fully characterized and exists in both solution and the solid state as a dimeric species; dissociation into monomers faces a high barrier of over 40 kcal/mol, according to Density Function Theory computations. This is due to stabilization of the dimer by dispersion forces. The computations show that the dimer has an S = 1 ground state, but in solution, partial dissociation into an intermediate dimer which is an open shell singlet is possible, which accounts for the lower than expected magnetic susceptibility of 1.93 per dimer. Full dissociation into reactive monomers does not occur, based on the observed lack of reactivity with carbon dioxide. All of these com-pounds react with water to form a mu-oxo dinuclear species, which reacts further with dioxygen to form oxidized peroxo and oxo Ti(IV) complexes. All three of these compounds were fully characterized.
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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) | 0.002 | 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".