Strongly Blue Luminescent Cationic Iridium(III) Complexes with an Electron‐Rich Ancillary Ligand: Evaluation of Their Optoelectronic and Electrochemiluminescence Properties
Bibliographic record
Abstract
Abstract Two strongly blue luminescent cationic heteroleptic iridium complexes 1b and 2b bearing a 4,4′‐bis(dimethylamino)‐2,2′‐bipyridine (dmabpy) ancillary ligand and either 1‐benzyl‐4‐(2,4‐difluorophenyl)‐1 H ‐1,2,3‐triazole (dFphtl) or 2‐(2,4‐difluorophenyl)‐5‐methylpyridine (dFMeppyH), respectively, have been synthesized and fully characterized. In comparison with other analogues, the interplay of the triazole unit with the dmabpy unit and methylation of the pyridine ring are discussed with respect to the photophysical, electrochemical, and electrochemiluminescent (ECL) properties of the complexes. The two complexes, 1b and 2b , are blue emitters with λ max = 495 and 494 nm, respectively. The nature of the excited states was established by various photophysical and photochemical experiments as well as DFT calculations. Both complexes emit from a ligand‐centered state, however, the emission of 1b possesses significant charge‐transfer character, which is absent in 2b . The presence of the methyl group on the cyclometalating ligand leads only to a modest increase in the radiative rate constant, k r , but otherwise does not appreciably influence the optoelectronic properties of the complex compared with the non‐methylated analogue. In contrast, the efficacy of the ECL emission when scanning to 2.50 V is strongly influenced by the presence of the methyl group. ECL emission is also enhanced in complexes bearing dmabpy ancillary ligands compared with those containing d t Bubpy ligands. The two complexes exhibit similar electrochemical behavior. Incorporation of the dmabpy ligand shifts both the oxidation and reduction cathodically. The combination of the dmabpy and dFphtl groups increases the redox potential difference and thus the HOMO–LUMO gap but the emission is not further blueshifted. Thus, the structural modification of the cyclometalating ligand, although only modestly tuning the emission energy, modulates the nature of the excited state and the efficiency of the ECL process.
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How this classification was reachedexpand
Full frame distilled prediction
Teacher imitationNot 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.
Codex and Gemma teacher scores by category
| Category | Codex | Gemma |
|---|---|---|
| Metaresearch | 0.001 | 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 | 0.001 | 0.000 |
| Research integrity | 0.000 | 0.001 |
| Insufficient payload (model declined to judge) | 0.000 | 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 teacher head, 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".