Magnetic Circular Dichroism of Phthalocyanine (M = Mg, Zn) and Tetraazaporphyrin (M = Mg, Zn, Ni) Metal Complexes. A Computational Study Based on Time-Dependent Density Functional Theory
Bibliographic record
Abstract
We present here simulated magnetic circular dichroism (MCD) spectra of MTAP (M=Mg, Ni, Zn) and MPc (M=Mg, Zn) where TAP=tetraazaporphyrin and Pc=phthalocyanine. The study is based on magnetically perturbed time-dependent density functional theory (MP-TDDFT) and a newly implemented method for the calculation of A and B terms from the theory of MCD. It follows from our investigation that the MCD spectrum for the MTAP and MPc systems in the Q-band region consists of a single positive A term augmented by a positive B term, in agreement with experiment where available. The Q band can be fully characterized in terms of the 2a1u-->2eg one-electron excitation. For the aza systems MgTAP and ZnTAP, the simulated MCD spectra in the Soret region are dominated by the two one-electron excitations 2a2u-->2eg and 1a2u-->2eg and has the appearance of a positive A term (with values between 1.33-1.55, depending on the MTAP system) made asymmetric by a negative B term, in good agreement with experiment. We find, in agreement with all available experimental findings on MPc (M=Mg, Zn) type systems, that the MCD spectra in the Soret region are dominated by two transitions with positive A/ D-term values and two negative B/ D-term values. The major contribution to the two transitions comes from the 2a2u-->2eg and 1a2u-->2eg one-electron excitations. It appears that the ratio of A/ B for the term parameters is underestimated by theory.
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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) | 0.001 | 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) | 0.009 | 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".