Electronic and Steric Influence of Trans Axial Base on the Stereoelectronic Properties of Cobalamins
Bibliographic record
Abstract
Density functional theory (DFT) has been applied to investigate the relationship between steric and electronic properties of the trans axial base and energetics of Co−C bond cleavage in models of coenzyme B 12 . By using structurally reliable six-coordinate models, B-[Co III (corrin)]-R +, it was shown that for a given base (B) the energy of homolytic cobalt−carbon bond cleavage correctly follows the Co−C R bond lengthening. For a given axial ligand (R) the dissociation energy is very weakly dependent on the trans axial base and correlates with its basicity. Analysis of the five-coordinate homolysis products, B-[Co II (corrin)] +, shows that the Co II −N B bond length is in the range of ∼2.2 Å, slightly shorter in comparison to six-coordinate analogues, while five-coordinate heterolysis products, B-[Co III (corrin)] +2, have the Co III −N B bond significantly shorter ∼1.9 Å. This noticeable difference suggests that controlling the Co−N B bond length could be an effective way to promote biologically important homolysis of the Co−C bond in B 12 -dependent enzymes over abiological heterolysis.
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 | 0.001 |
| 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) | 0.003 | 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".