MétaCan
Menu
Back to cohort
Record W2055090396 · doi:10.1039/b500996k

Indices for predicting the quality of leaving groups

2005· article· en· W2055090396 on OpenAlexafffund
Paul W. Ayers, James S. M. Anderson, Juan I. Rodríguez, Zobia Jawed

Bibliographic record

VenuePhysical Chemistry Chemical Physics · 2005
Typearticle
Languageen
FieldChemistry
TopicChemical Reaction Mechanisms
Canadian institutionsMcMaster University
FundersNatural Sciences and Engineering Research Council of Canada
KeywordsLeaving groupChemistryCarbocationElectrophileNucleophileCarbanionSubstitution reactionIonizationIonization energyElectrophilic substitutionReactivity (psychology)Computational chemistryNucleophilic substitutionIonElectronMedicinal chemistryOrganic chemistryPhysicsQuantum mechanics

Abstract

fetched live from OpenAlex

The inherent quality of leaving groups in chemical reactions is related to their ionization potential and electron affinity using a quadratic model for the dependence of the energy on the number of electrons. A good leaving group for nucleophilic substitution/elimination reactions is one where the difference in energy between the system with the "optimum" number of electrons and the anion is small. Similarly, a good leaving group for electrophilic substitution/elimination reactions is one where the difference in energy between the system with the optimum number of electrons and the cation is small. This insight allows us to define indices for the quality of leaving groups in nucleophilic and electrophilic reactivity, which we term the nucleofugality and the electrofugality, respectively. These indices are useful not only for predicting the quality of leaving groups in organic reactions, but also for explaining the stability of carbocations, carbanions, and trends in pKa.

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 imitation

Not 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.

metaresearch head score (Codex)0.002
metaresearch head score (Gemma)0.008
Version: metacan-v3-hybrid-931329e0061cValidation status: machine_predicted_unvalidated
Candidate categoriesnone
Consensus categoriesnone
DomainCandidate signal: none · Consensus signal: none
Study designCandidate signal: Theoretical or conceptual · Consensus signal: none
GenreCandidate signal: Empirical · Consensus signal: Empirical
Teacher disagreement score0.004
Threshold uncertainty score0.008

Distilled classifier scores by category (both heads)

CategoryCodexGemma
Metaresearch0.0020.008
Meta-epidemiology (narrow)0.0010.000
Meta-epidemiology (broad)0.0010.001
Bibliometrics0.0040.002
Science and technology studies0.0000.001
Scholarly communication0.0010.002
Open science0.0010.001
Research integrity0.0010.001
Insufficient payload (model declined to judge)0.0020.001

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.

Opus teacher head0.031
GPT teacher head0.309
Teacher spread0.278 · how far apart the two teachers sit on this one work
Validation statusscore_only:v0-immature-baseline · verbatim from the scoring run: score_only means the number may rank works, and no category label ships from it

Classification

machine, unvalidated

Machine predicted; a candidate call from one source (direct Gemma or distilled Codex), not a consensus.

The models applied no category: nothing in the taxonomy fit this work.
Study designTheoretical or conceptual
Domainnot available
GenreEmpirical

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".

Quick stats

Citations147
Published2005
Admission routes2
Has abstractyes

Explore more

Same venuePhysical Chemistry Chemical PhysicsSame topicChemical Reaction MechanismsFrench-language works237,207