Synthesis, spectral and redox properties of tetraammine dioxolene ruthenium complexes †
Bibliographic record
Abstract
A series of species [RuIII(NH3)4(Cat-R)]n+ have been synthesized where Cat-R is a catecholate dianion having the substituent R = CO2−, CO2H, OMe or H. These so-called parent species were characterized by their electronic spectra, FTIR, mass spectrum, cyclic voltammetry and EPR. Controlled potential reduction yields [RuII(NH3)4(Cat-R)](n − 1)+ while controlled potential oxidation yields [RuII(NH3)4(Q-R)](n + 1)+ (Q-R = substituted quinone). Density Functional Theory (DFT) was primarily used to explore the electronic structures of these complexes. Application of the INDO semi-empirical model proved less useful. Time dependent density functional response theory was used to calculate the electronic spectra of the species with R = H. The electronic spectra of the closed shell species are well reproduced by the calculations. The physical properties of these complexes indicate a charge delocalized system reminiscent of a delocalized organic molecule. The simple valence descriptions noted above are convenient to use but do not reflect the actual electronic structure. The electronic spectra of the parent species are temperature dependent. The visible region charge transfer band shifts by about 1500 cm−1 to higher energy in acidic media at liquid nitrogen temperature. This is interpreted in terms of solvent effects rather than valence tautomerism. The electrochemical properties of [RuIII(NH3)4(Cat-R)], in aqueous solution, reveal the first example of a reversible and stable Ru–quinone species in that medium. The pKa values for several dioxolene species, with R = CO2−, are derived from a Pourbaix diagram.
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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) | 0.001 | 0.001 |
| 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 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".