MétaCan
Menu
Back to cohort

Thermolysis of N-tetramethylpiperidinyl esters: homolytic fragmentation and induced decomposition

2008· article· en· W812810523 on OpenAlex

Why this work is in the frame

A frame that forgets how it found something cannot be audited. These are the routes that admitted this work.

affAt least one author lists a Canadian institution in the pinned OpenAlex snapshot.
fundA Canadian funder is recorded on the work.

Bibliographic record

VenueARKIVOC · 2008
Typearticle
Languageen
FieldChemistry
TopicFree Radicals and Antioxidants
Canadian institutionsUniversity of Toronto
FundersNatural Sciences and Engineering Research Council of CanadaAmerican Chemical Society Petroleum Research FundCanada Council for the Arts
KeywordsHomolysisChemistryThermal decompositionFragmentation (computing)DecompositionPhotochemistryOrganic chemistryRadical

Abstract

fetched live from OpenAlex

The esters PhCH(OT)CO 2 T (2), PhCH 2 CO 2 T (5), PhCO 2 T, (6), and 1-AdCO 2 T (7, Ad = 1adamantyl), T = 2,2,6,6-tetramethyl-N-piperidinyl, undergo thermal decomposition at 120 C in toluene with the formation of carboxylic acids, 2,2,6,6-tetramethylpiperidine (TH), and bibenzyl in all cases, indicative of the formation of 2,2,6,6-tetramethylpiperidinyl radicals, but excluding the formation of the radicals PhCH 2 CO 2 and 1-AdCO 2 . Qualitative kinetic measurements show that 5-7 react much faster than expected for rate-limiting bond-homolysis, suggesting the occurrence of induced decomposition. Addition of 2,6-di-tert-butyl-4-methylphenol (BHT) to the reaction of PhCH 2 CO 2 T in hexane accelerates the reaction, with a first-order dependence on [BHT], and leads to the formation of the characteristic dimers 9 and 10 from 2,6-di-tert-butyl-4methylphenoxyl radical (12). These reactions of the esters 5-7 are interpreted to occur by molecule-induced homolysis, in which a hydrogen atom from toluene or BHT is transferred to oxygen forming RCO 2 H and the 2,2,6,6-tetramethylpiperidinyl radical T in a concerted process. Comparable behavior is observed for reactions in chloroform. PhCH(OT)CO 2 T (2) is proposed to form an intermediate PhCH()CO 2 T (1) which gives -lactone 19. Density functional calculations are used to model the overall energy changes in these reactions.

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.

Full frame distilled prediction

Teacher imitation

Not 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.

metaresearch head score (Codex)0.000
metaresearch head score (Gemma)0.000
Version: codex-gemma-dda1882f352aValidation status: machine_predicted_unvalidated
Candidate categoriesnone
Consensus categoriesnone
DomainCandidate signal: none · Consensus signal: none
Study designCandidate signal: Bench or experimental · Consensus signal: Bench or experimental
GenreCandidate signal: Empirical · Consensus signal: Empirical
Teacher disagreement score0.020
Threshold uncertainty score0.334

Codex and Gemma teacher scores by category

CategoryCodexGemma
Metaresearch0.0000.000
Meta-epidemiology (narrow)0.0000.000
Meta-epidemiology (broad)0.0000.000
Bibliometrics0.0000.000
Science and technology studies0.0000.000
Scholarly communication0.0000.000
Open science0.0000.000
Research integrity0.0000.000
Insufficient payload (model declined to judge)0.0000.000

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.

Opus teacher head0.020
GPT teacher head0.257
Teacher spread0.237 · 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