Conjugated Oligomers and Polymers of <i>cis</i>- and <i>trans</i>-Platinum(II)-<i>para-</i> and <i>ortho</i>-bis(ethynylbenzene)quinone Diimine
Bibliographic record
Abstract
Three conjugated polymers of the type (−spacer−C≡C−PtL 2 −C≡C−) n, with spacer = para - and ortho -bis(diphenyl(tetramethoxy)quinone diimine) and L = PEt 3, were synthesized as the cis - and trans -isomers about the Pt. The three combinations (spacer/PtL 2 Cl 2 ), ortho/trans, para/trans, and para/cis led to polydispersed polymers, which upon fractionation provided more monodispersed materials with M n ranging from 3600 to 32400 (GPC). The spacer ortho -bis(diphenylethynyl)tetramethoxyquinone diimine reacts with cis -PtL 2 Cl 2 to form small oligomers and a chelate cyclic complex ( 7 ), which was used as a model compound. All materials along with the aryl−C≡C−PtL 2 − C≡C−aryl models (L = PEt 3; aryl = C 6 H 5, 2,4,6-C 6 H 2 Me 3; 2,4,5-C 6 H 2 Me 3 ) were studied by 1 H and 31 P NMR, IR, UV–vis, TGA, DSC, luminescence spectroscopy, photophysics, and cyclic voltammetry. The UV–vis spectra exhibit an intramolecular low-energy and low-intensity charge transfer band (CT) assigned to π(Ph−C≡C) (for organics) and π/d xy ((Ph−C≡C) 2 Pt) (for organometallics) to the π*(quinone diimine), as demonstrated by comparison with a corresponding amine derivative (i.e., no CT band) and corroborated by DFT and TDDFT. The polymers and 7 are not luminescent at room temperature (solid and solution). However in 2MeTHF at 77 K, the polymers bearing the combination ortho/trans and para/cis as well as the model compound 7 exhibit higher energy phosphorescence (T n → S 0 ) originating from the ππ*/d xy ((Ph−C≡C) 2 Pt) excited states. A correlation between the structural parameters (angle made by the PtP 2 (C≡C) 2 vs the aryl planes, angle made by the aryl and the quinone diimine planes, molecular weight) with the calculated oscillator strength, absorptivities, and the observed position of the lowest energy absorption bands is demonstrated. Finally, upper energy delayed fluorescence (S n → S 0 ) was detected for the polymers and 7 at 77 K and was assigned to T 1 −T 1 interactions via aggregation as its intensity varies with the concentration.
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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 | 0.000 | 0.000 |
| 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) | 0.001 | 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".