The synthesis and X-ray crystal structures of rare earth(III) perfluoroadipate complexes — Novel coordination polymers
Bibliographic record
Abstract
A representative series of polymeric hydrated lanthanoid perfluoroadipates [Ln 2 (pfad) 3 (H 2 O) n ]·mH 2 O (Ln = La, Ce, Nd, Gd, Yb) has been prepared from the reaction of perfluoroadipic acid with either the appropriate lanthanoid oxide or Ce 2 (CO 3 ) 3 in water. X-ray crystal structures showed [Ln 2 (pfad) 3 (H 2 O) 10 ]·4H 2 O (La, Nd) to be two-dimensional inorganic polymers, which contain nine-coordinate Ln atoms to which are attached five water molecules and four carboxylate oxygen atoms. Two pfad ligands bridge two Ln atoms through one carboxylate group, the other being free, whilst one pfad ligand bridges four Ln atoms in a µ 4 -(η 1 ,η 1 /η 1 ,η 1 ) manner. In two-dimensional polymeric [Yb 2 (pfad) 2 (H 2 O) 8 ](pfad)·6H 2 O, each eight-coordinate ytterbium atom has four water ligands and four carboxylate oxygen donor atoms. The two carboxylate ligands bind in a µ 4 -(η 1 ,η 1 /η 1 ,η 1 ) manner, and there is one pfad counter-ion per two ytterbium atoms. These structures show features quite different from those of many lanthanoid adipate complexes [Ln 2 (ad) 3 (H 2 O) n ]·mH 2 O, but there is no F-Ln coordination. From the reaction of [Nd 2 (pfad) 3 (H 2 O) 10 ]·4H 2 O with benzene-1,2-disulfonic acid (H 2 bds), the mixed ligand complex [Nd 2 (bds) 2 (pfad)(H 2 O) 8 ] was isolated. This is a one-dimensional polymer featuring Nd 2 (bds) 2 units linked together by µ-η 2 ,η 2 pfad ligands. Each Nd atom is nine-coordinate with three sulfonate oxygen donors, two carboxylate oxygen atoms, and four water ligands, and the bds ligands bind in the new µ-η 2 (O,O′),η 1 (O′′) manner for Ln complexes. Surprisingly, [Na 2 pfad] was isolated unhydrated from water, the six-coordinate Na atoms being coordinated by four carboxylate oxygen atoms and two (C)-F atoms in an octahedral array. The ligands are duodecadentate, each –CF 2 CO 2 unit binding to five different sodium ions through four oxygen and one α-F atom with the second α-F atom bound to a sodium ion in a OC(O)CF-Na chelate ring.Key words: rare earths, lanthanoid, X-ray crystal structures, adipates, carboxylates.
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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) | 0.000 | 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 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".