HOMO–LUMO energy gap control in platinum(<scp>ii</scp>) biphenyl complexes containing 2,2′-bipyridine ligands
Bibliographic record
Abstract
A series of platinum(ii) biphenyl 2,2'-bipyridine complexes containing electron-donating and electron-withdrawing moieties on the 4 and 4' positions of the bipyridine ligand exhibit emission from excited states in the 600 nm region of the spectrum upon excitation in the metal-to-ligand charge transfer transition located near 450 nm. These complexes are distorted from planarity based on both single crystal structure determinations and density functional theory (DFT) calculations of isolated molecules in acetonitrile. The DFT also reveals the geometry of the lowest-lying triplet state (LLTS) of each complex that is important for emission behavior. The LLTS are assigned based on the electron spin density distributions and correlated with the singlet excited states to understand the mechanism of electronic excitation and relaxation. Time-dependent DFT calculations are performed to compute the singlet excited state energies of these complexes so as to help interpret their UV-Vis absorption spectra. Computational and experimental results, including absorption and emission energy maxima, electrochemical reduction potentials, LLTS, singlet excited states, and LUMO and HOMO energies, exhibit linear correlations with the Hammett constants for para-substituents σp. These correlations are employed to screen complexes that have not yet been synthesized. The correlation analysis indicates that the electronic structure and the HOMO-LUMO energy gap in Pt(ii) complexes can be effectively controlled using electron-donating and electron-withdrawing moieties covalently bonded to the ligands. The information presented in this paper provides a better understanding of the fundamental electronic and thermodynamic behavior of these complexes and could be used to design systems with specific applications.
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 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 | 0.000 | 0.000 |
| Meta-epidemiology (narrow) | 0.000 | 0.000 |
| Meta-epidemiology (broad) | 0.000 | 0.000 |
| Bibliometrics | 0.000 | 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 | 0.001 |
| 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".