The neutral complex [Cr<sup>III</sup><sub>4</sub>(μ<sub>3</sub>-O)<sub>2</sub>(μ<sub>2</sub>-CH<sub>3</sub>CO<sub>2</sub>)<sub>7</sub>(<sup>t</sup>bpy<sup>0</sup>)(<sup>t</sup>bpy<sup>•</sup>)]<sup>0</sup> — a tetranuclear Cr(III) species containing a neutral (bpy<sup>0</sup>) and a π-radical anion (bpy<sup>•</sup>)<sup>1–</sup>
Bibliographic record
Abstract
The tetranuclear neutral species [Cr III 4 (μ 3 -O) 2 (μ 2 -CH 3 CO 2 ) 7 ( t bpy 0 )( t bpy • )] 0 ·3THF has been prepared from a mixture of [Cr II 2 (μ 2 -CH 3 CO 2 ) 4 ]·2H 2 O and 4,4′-di-tert-butyl-2,2′-bipyridine (1:2) in tetrahydrofuran (THF) under anaerobic conditions. Black crystals of [Cr III 4 (μ-O) 2 (μ-CH 3 CO 2 ) 7 ( t bpy) 2 ] 0 were grown and investigated by X-ray crystallography: a [Cr 4 O 2 ] 8+ butterfly core structure has been identified. In addition, the presence of seven μ 2 -acetate bridges, a neutral ( t bpy 0 ) ligand, and a single π-radical anion ( t bpy • ) 1– have been clearly identified. The magnetic properties have been investigated by solid-state SQUID (superconducting quantum interference device) measurements (2–300 K) and a coupling model is presented. Its X-band electron paramagnetic resonance spectrum has been recorded at 10 and 300 K in toluene solution and successfully simulated. The spin of the ( t bpy • ) 1– radical couples strongly antiferromagnetically to one Cr(III) center (J 4 = –129 cm −1 ). These properties are compared with those reported previously for the monocationic species [Cr III 4 (μ 3 -O) 2 (μ 2 -CH 3 CO 2 ) 7 (bpy 0 ) 2 ](PF 6 ) in Bino et al. (Inorg. Chem. 1991, 30, 856).
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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 | 0.018 | 0.009 |
| Meta-epidemiology (narrow) | 0.018 | 0.019 |
| Meta-epidemiology (broad) | 0.018 | 0.010 |
| Bibliometrics | 0.008 | 0.012 |
| Science and technology studies | 0.014 | 0.016 |
| Scholarly communication | 0.014 | 0.012 |
| Open science | 0.020 | 0.005 |
| Research integrity | 0.011 | 0.022 |
| Insufficient payload (model declined to judge) | 0.002 | 0.004 |
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; both teacher heads agree on what is shown here.
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".