A New Silver(I) Aggregate Having an Octagonal Ag<sub>4</sub>S<sub>4</sub> Core Where μ<sub>3</sub>‐S Bonding Interactions Lead to a Nanotube Assembly that Exhibits Quasiaromaticity
Bibliographic record
Abstract
Abstract Silver(I) chloride reacts with 2‐mercapto‐3,4,5,6‐tetrahydropyrimidine (StpmH2, C4H8N2S) in DMSO with excess triethylamine to give a complex of formula {[Ag4Cl4(μ3‐StpmH2)4]n} (1). The product was characterized by elemental analyses, FTIR far‐IR, UV/Vis, and 1H and 109Ag NMR spectroscopic techniques. The 109Ag NMR spectroscopic data of the complexes {[Ag6(μ2‐Br)6(μ2‐StpmH2)4(μ3‐StpmH2)2]n} (2) and {[Ag4(μ2‐StpmH2)6](NO3)4}n (3) are also reported here for comparison. Crystal structure of complex 1 was determined by X‐ray diffraction at 100(1) K. Complex 1, C4H8AgClN2S, crystallized in the tetragonal system, space group P4cc, a = 15.7761(9) Å, b = 15.7761(9) Å, c = 6.9624(8) Å, V = 1732.8(2) Å3, Z = 2. Each metal ion is bonded to one terminal Cl atom and three μ3‐S atoms from three StpmH2 ligands. Four silver ions are bridged by four sulfur atoms forming an octagonal Ag4S4 core. Each AgI ion of one core is also bridged to an AgI ion of another core through a sulfur atom, which forms an infinite nanotube structure. A computational study utilizing the method of nucleus‐independent chemical shifts (NICS) showed that the Ag4S4 core exhibits strong quasiaromaticity at the geometric cage center. To the best of our knowledge, this is the first example of an AgI cluster that presents quasiaromaticity and stacking interactions.(© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2007)
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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".