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Record W1988393823 · doi:10.1021/ma048202t

Photophysics and Solvent-Induced Aggregation of 2,7-Carbazole-Based Conjugated Polymers

2005· article· en· W1988393823 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.

Bibliographic record

VenueMacromolecules · 2005
Typearticle
Languageen
FieldMaterials Science
TopicConducting polymers and applications
Canadian institutionsUniversité de MontréalUniversité Laval
Fundersnot available
KeywordsSolvatochromismCarbazoleThiophenePhotochemistryChemistryConjugated systemPolymerFluorescenceQuenching (fluorescence)AlkylSolvent effectsBathochromic shiftSolventPolymer chemistryOrganic chemistry

Abstract

fetched live from OpenAlex

We report on the optical, photophysical, and solvatochromic properties of five carbazole-based polymers, namely poly( N -octyl-2,7-carbazolediyl) (POC), poly( N -(2‘-ethylhexyl)-2,7-carbazolediyl) (PEHC), poly( N -octyl-2,7-carbazolediyl- alt -2,5-thiophene) (POCT), poly( N -(2‘-ethylhexyl)-2,7-carbazolediyl- alt -2,5-thiophene) (PEHCT), and poly( N -octyl-2,7-carbazoleneethynylene) (POCE). Compared to their corresponding triads, the absorption and fluorescence spectra of polycarbazoles in chloroform are red-shifted due to an increase of the effective conjugation length. Among the polycarbazoles investigated, the optical spectra of POCT are the more red-shifted due to the electron donor properties of the thiophene rings. The variation of the photophysical properties of the polycarbazoles mainly involves radiative processes ( k F ). From steady-state and time-resolved fluorescence studies in chloroform/methanol mixtures, all polymers have revealed solvatochromic effects, which have been related to the formation of H- and/or J-aggregates. On one hand, the aggregation process found on homopolymers (POC and PEHC) and copolymers involving thiophene units (POCT and PEHCT) is accompanied by a strong quenching of the photoluminescence efficiency. On the other hand, for POCE, the molecular interactions between the polymeric chains are not strong enough to induce a deactivation of the fluorescence. Finally, it is observed that the nature of alkyl chains on the nitrogen atoms of the carbazole moieties has a significant effect on the emission properties of the polymers.

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 score0.011
Threshold uncertainty score0.410

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 head0.016
GPT teacher head0.251
Teacher spread0.235 · 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