Synthesis and Characterizations of Linear and Ladder Conjugated Polymers
Bibliographic record
Abstract
Semiconducting polymers have gained tremendous attention in the past decades as a potential alternative over Si-based semiconductors. The research on tuning the band gap of semiconducting polymers has mainly focused on the development of new electron donor and acceptor building blocks. Post-polymerization such as annulations and modification of functional groups is considered as an effective approach to the band-gap tuning for semiconducting polymers.The first part of this thesis describes the synthesis and characterization of ladder and linear-ladder polymers by post-polymerization annulations. 8-Octylnaphtho[2,3-c]thiophene-4,9-dione (NTDO) having the two keto groups was incorporated into conjugated linear polymers, which were then treated with Lawesson's Reagent (LR) for post-polymerization annulation. The obtained ladder and linear-ladder polymers had a lower energy band gap and absorption at a longer wavelength in comparison with their precursor polymers. The linear-ladder polymers containing of the electron-donating thiophene units and electron-withdrawing benzothiadiazole units had the absorption onset in the NIR region, e.g., at 1300 nm and 1000 nm, respectively.The second part discusses chemical transformations of the NTDO-containing conjugated polymers. The transformation by sequential reduction, dehydration, and esterification on the NTDO homopolymer was successful. The energy band gap decreased, absorption maxima were red-shifted and the absorption spectrum was broadened after chemical transformation. The transformation of the keto group of NTDO-based D-A polymers to the corresponding dicyanovinylene group unexpectedly resulted in an increase of the LUMO energy level and therefore an increase in energy band gap. In the third part of this thesis, the building block of thieno[3,4-c]pyrrole-4,6-dione (TPD) was incorporated into conjugated linear polymers. Treatment of TPD-containing polymers with LR led to conversion of the keto group to thio-keto instead of annulation by intramolecular coupling. The obtained polymer displayed a hypsochromic shift and a higher energy band gap.In the final part of this thesis, fluorene-based conjugated polymers containing the AIE-active tetraphenylethene and dicarboxylate pseudocrown as an ion receptor were synthesized and the optical sensing for lead ion was investigated. The study showed that polymer structure, solvent polarity, and nature of probe-analyte complex play collective roles in the dual-mode fluorescence detection for lead ion.
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 | 0.000 |
| Meta-epidemiology (narrow) | 0.000 | 0.000 |
| Meta-epidemiology (broad) | 0.000 | 0.000 |
| Bibliometrics | 0.001 | 0.001 |
| 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".