Molecular-level screening of substituted porphyrinoid/azomethine macrocycles for indoor light harvesting: DFT/TD-DFT, Hammett analysis and multi-source spectral matching
Synthetic Metals, cilt.320, 2026 (SCI-Expanded, Scopus)
- Yayın Türü: Makale / Tam Makale
- Cilt numarası: 320
- Basım Tarihi: 2026
- Doi Numarası: 10.1016/j.synthmet.2026.118244
- Dergi Adı: Synthetic Metals
- Derginin Tarandığı İndeksler: Science Citation Index Expanded (SCI-EXPANDED), Scopus, Chemical Abstracts Core, Chimica, Compendex, INSPEC
- Anahtar Kelimeler: Azomethine compounds, Indoor light harvesting, Organic semiconductors, Porphyrinoid macrocycles, Spectral matching
- Hacettepe Üniversitesi Adresli: Evet
Özet
Indoor organic photovoltaics require molecular absorbers whose optical responses are compatible with artificial illumination. Here, a series of substituted porphyrinoid/azomethine macrocycles (B1 – B13) was evaluated as molecular-level candidates for indoor light harvesting using DFT and TD-DFT calculations. Benchmarking against the experimental Soret- and Q-region features of two structurally related corroles identified HSEH1PBE/6–31 G** as the best-performing method, with a two-reference mean absolute error of 3.61 nm. Peripheral substitution systematically influenced frontier-orbital energies, HOMO–LUMO gaps, absorption maxima, reorganization energies, and source-dependent spectral descriptors. Composite Hammett-type relationships showed that increasing electron-withdrawing character stabilizes both frontier orbitals, preferentially lowers the LUMO, narrows the energy gap, and red-shifts absorption. Transition intensity, however, was not determined by substituent strength alone. Electron reorganization energies were consistently higher than the corresponding hole reorganization energies, indicating a modest electron–hole relaxation asymmetry. Excited-state analysis separated the series into predominantly local or mixed derivatives (B1 and B3 – B8) and derivatives with stronger interfragment charge-transfer character (B2 and B9 – B13). This qualitative classification was retained in CAM-B3LYP calculations. Spectral matching under CIE LED-B2, LED-B3, LED-B4, and FL10 illumination produced source- and descriptor-dependent rankings. B6 gave the highest absorbed fraction under three of the four sources, whereas B5 and B12 showed stronger normalized spectral-shape alignment under selected illuminants. Overall, B6 , B12 , and B13 represent complementary candidates for subsequent synthesis, thin-film characterization, and device-level validation rather than confirmed high-performance materials.