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Record W4232913035 · doi:10.22215/etd/2013-09901

Study of Chromogenic Zwitterionic Chromophores

2013· dissertation· nl· W4232913035 on OpenAlexaff
Yasaman Aghili

Bibliographic record

Venuenot available
Typedissertation
Languagenl
FieldMaterials Science
TopicPhotochromic and Fluorescence Chemistry
Canadian institutionsCarleton University
Fundersnot available
KeywordsChromophoreChromogenicSolvatochromismPhotochemistryMagentaCyanPolymerMaterials scienceChemistryPolymer chemistrySolventOrganic chemistryOpticsChromatography

Abstract

fetched live from OpenAlex

To understand the relationship of structure and chromogenic properties of zwitterionic chromophores, dicyanomethane-based (FDCN and MPCT) and tricyanoquinodimethanebased (PpQDM) chromophores were studied. These chromophores are selected based on the design to have different conjugation lengths and thus have the three primary colors: yellow (FDCN), magenta (MPCT) and cyan (PpQDM). All of the three chromophores exhibited intense absorption in the UV-Vis region with relatively high molar extinction coefficients (ε) attributed to strong charge transfer (CT) from the negatively charge dicyanomethanide to the positively charged nitrogen in pyridinium.In this regard, the chromogenic (i.e., color-changing) properties, including solvatochromism, halochromism, and thermo-halochromism of the three chromophores were studied in solution, polymer gel and solid polymer. Distinctive chromogenic features of these zwitterionic chromophores were governed by structural factors, including the strength of the donor and acceptor moieties in addition to the nature of the bridging unit. Thermohalochromic behavior of the chromophores was based on the protonation of the chromophore by acid and consequently deprotonation by heating. Moreover, the colorchanging process could be reversible and irreversible, depending on the nature of a medium. Using malononitrile and a polymer gel as a medium, thermo-halochromic process was irreversible, whereas in a suitable polymer host (i.e., PS, PMMA and PS-co-PMMA), these chromophores showed reversible thermo-halochromic behavior.Strong charge transfer (CT) of the zwitterionic chromophores in UV-Vis range in addition to their easily CT turned on-off properties eventually led to perform an evaluation based on their potential application as indirect thermo-indicators. FDCN (as the studied chromophore) demonstrated to be capable of reversibly switching on and off the fluorescence of the commercial fluorescent dyes under externalstimuli of heat and pH changes.

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)0.000
metaresearch head score (Gemma)0.000
Version: metacan-v3-hybrid-931329e0061cValidation 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: Other · Consensus signal: none
Teacher disagreement score0.001
Threshold uncertainty score0.003

Distilled classifier scores by category (both heads)

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)0.0010.000

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 head0.017
GPT teacher head0.272
Teacher spread0.254 · 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 designBench or experimental
Domainnot available
GenreOther

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".

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Citations0
Published2013
Admission routes1
Has abstractyes

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