Preparation, Characterization, X-ray Crystal Structure, and Energetics of Cesium 5-Cyano-1,2,3,4-Tetrazolate: Cs[NCCNNNN]
Bibliographic record
Abstract
Cesium 5-cyano-1,2,3,4-tetrazolate, Cs[NCCNNNN] (Cs1), was prepared in 100% yield by a 3 + 2 cycloaddition reaction of CsN3 and (CN)2 in SO2. Cs1 forms monoclinic crystals (a = 8.297(2) A, b = 11.040(3) A, c = 6.983(2) A, beta = 120.31(2) degrees, space group C2/c, Z = 4, R1 = 0.048, wR2 = 0.120 for 1217 independent reflections). Cs1 is best described as a three-dimensional array of cations and anions connected by weak Cs(+)-N delta- contacts. The cations and anions each form a diamond-type lattice (tetrahedral arrangement of ions) with the counterions lying in hexagonal channels running parallel to the c-axis. The anions in the channels form stacks with the CN groups pointing in opposite directions in adjacent layers. The calculated (RB3PW91/6-311 + G*) geometry of 1 is in agreement with the X-ray crystal structure, and the calculated vibrational spectrum is in good agreement with the observed FT-IR and FT-Raman spectra. The lattice enthalpies and heats of formation of M1 (M = Cs, K) as well as the enthalpy of formation from MN3(s) and (CN)2(g) were estimated. The 13C and 14N NMR spectra of Cs1 are also reported. The ionization potential (450.7 kJ mol) and electron affinity (427.4 kJ/mol) of 1 were calculated. Attempts to oxidize 1 with AsF5 led to the formation of Cs1.xAsF5 (x approximately 2). The 7 pi dianion [NCCNNNN].2- is calculated to be a stable entity in the gas phase, but Cs(2)1 is estimated to be unstable with respect to dissociation to 2 CsCN and 3/2 N2 (delta Hdiss = -132.4 kJ/mol). The preparation of the potassium salt of 1 and the corresponding thermodynamic quantities are reported.
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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 | 0.001 |
| Meta-epidemiology (narrow) | 0.000 | 0.000 |
| Meta-epidemiology (broad) | 0.000 | 0.000 |
| Bibliometrics | 0.000 | 0.001 |
| Science and technology studies | 0.000 | 0.000 |
| Scholarly communication | 0.000 | 0.000 |
| Open science | 0.001 | 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".