Hydrogenating atomic coinage metal cations (group 11) with H2 on charged He droplets (T<10 K) doped with metal Atoms: Early stages, ligation energies, core structures, group variations, and relativistic effects
Bibliographic record
Abstract
Experimental mass-spectrometric results are reported which demonstrate that ionized helium nanodroplets (at T < 10 K) doped with the coinage metal atoms M = Cu, Ag or Au, and then exposed to molecular hydrogen, provide an abundance of singly and multiply hydrogenated coinage metal cations M + (H 2 ) n and MH + (H 2 ) n with n up to 25 and beyond. We explore here the information provided by observed distributions in the measured intensities of these ligated ions with n = 1–6 and use ab initio quantum chemical calculations to extract fundamental insights into variations in ligation energies and structures with increasing H 2 ligation and going down the Periodic Table (M + = Cu + , Ag + and Au + ) with an eye on the role of relativistic contributions to the ligation energies expected with the increasing nuclear charge of M + . “Magic” numbers of H 2 additions with relatively high intensity are apparent among the first 5, especially the first 2, H 2 additions. Very substantial relativistic enhancements of the third over the second-row ligation energies were computed, especially for Au + : 83 % and 60 % respectively, for the first two H 2 ligands intimately bonded to Au + , and 19 % and 67 % respectively, for the addition of the first two H 2 ligands to AuH + . Relativistic enhancements for the addition of a third H 2 ligand and beyond were found to be essentially negligible. • Charged He nano-droplets doped with coinage metal M atoms yield H 2 ligated M + and MH + . • “Magic” numbers of H 2 additions of relatively high intensity are seen among the first 5. • Calculations provide core structures for M + (H 2 ) n and MH + (H 2 ) n with n = 1 to 6. • Calculated ligation energies show variations down the Group with second-row minima. • Calculated H 2 ligation energies increase for Au + and AuH + due to relativistic effects.
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 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 | 0.001 | 0.001 |
| Science and technology studies | 0.000 | 0.000 |
| Scholarly communication | 0.000 | 0.001 |
| Open science | 0.000 | 0.000 |
| Research integrity | 0.000 | 0.001 |
| 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 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".