Synthesis and characterization of [M(DMSO)<sub>6</sub>][SnCl<sub>6</sub>] complexes (M = Fe<sup>2+</sup>, Co<sup>2+</sup>, and Ni<sup>2+</sup>) — An old mystery solved
Bibliographic record
Abstract
The synthesis of an "unknown" Fe(II) complex originally reported in 1973 and formulated then as [Fe(DMSO)5Cl][SnCl4] was thoroughly reproduced and the compound reformulated as the novel [Fe(DMSO)6][SnCl6] double complex salt. Current elemental analysis and IR and Mössbauer spectroscopy matched the original 1973 data, and Raman spectroscopy and single crystal X-ray diffraction provided additional confirmation of our reformulation. [Fe(DMSO)6][SnCl6] (1) crystallizes in the trigonal space group R[Formula: see text] with octahedral [Fe(DMSO)6]2+ and [SnCl6]2– complex ions with an Fe—O bond length of 2.121(3) Å. The same synthesis was extended to Co(II) and Ni(II) to generate the novel [Co(DMSO)6][SnCl6] (2), which crystallizes in the triclinic space group P[Formula: see text] with a Co—O bond length of 2.093(4)–2.113(5) Å, and [Ni(DMSO)6][SnCl6] (3), which crystallized in the trigonal R[Formula: see text] space group and has a Ni—O bond length of 2.062(2) Å. The Sn—Cl bond length in all three complexes ranged from 2.421(2) to 2.448(2) Å.Key words: DMSO complexes of Fe(II), Co(II) and Ni(II), SnCl62– salts, IR, Raman and Mössbauer spectroscopy, X-ray crystal structures.
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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) | 0.001 | 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".