Synthesis and Structure of a Calcium Polyphosphate with a Unique Criss-Cross Arrangement of Helical Phosphate Chains
Bibliographic record
Abstract
We report here the facile synthesis and structural characterization of γ-Ca(PO 3 ) 2, a novel polymorph of calcium polyphosphate. The single-step synthesis of this potential biomaterial was achieved using flux methods at 250 °C, yielding a single-phase product stable at room temperature. Single-crystal X-ray diffraction determined the structure to be of monoclinic symmetry ( a = 9.5669(2) Å, b = 9.5023(2) Å, c = 10.3717(3) Å, and β = 93.474(2)°, space group Cc ), with layers of helical polyphosphate chains directed alternately along the [110] and [−110] unit cell directions to produce a unique arrangement of criss-cross polyphosphate layers separated by calcium ions. Further structural characterization by MAS-NMR and FT-IR was found to be consistent with this structure. Thermal studies indicated that γ-Ca(PO 3 ) 2 is stable up to 690 °C, whereupon it irreversibly converts to the β-Ca(PO 3 ) 2 polymorph.
Fetched live from OpenAlex and de-inverted. Abstracts are not stored in this database: the inverted indexes are 8.6 GB of the frame’s 9.3 GB of text, and the host has 13 GB free.
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) | 0.000 | 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".