Saved in:
| Main Authors: | , , , |
|---|---|
| Format: | Artículo Open Access |
| Published: |
Wiley
2025
|
| Subjects: | |
| Online Access: | https://onlinelibrary.wiley.com/doi/10.1111/php.14045 |
| Tags: |
Add Tag
No Tags, Be the first to tag this record!
|
| _version_ | 1867010485549793280 |
|---|---|
| author | Leonardo M. F. Oliveira Danillo Valverde Gustavo Juliani Costa Antonio Carlos Borin |
| author_facet | Leonardo M. F. Oliveira Danillo Valverde Gustavo Juliani Costa Antonio Carlos Borin Leonardo M. F. Oliveira Danillo Valverde Gustavo Juliani Costa Antonio Carlos Borin |
| collection | Wiley Open Access |
| contents | Excited state relaxation mechanisms and tautomerism effects in 2,6‐Diamino‐8‐Azapurine Leonardo M. F. Oliveira Danillo Valverde Gustavo Juliani Costa Antonio Carlos Borin Photochemistry and Photobiology AbstractThe photochemistry of 9H‐2,6‐diamino‐8‐azapurine (9H‐8AZADAP), a promising fluorescent probe, was investigated using the Multi‐State Complete‐Active‐Space Second‐Order Perturbation Theory (MS‐CASPT2) quantum chemical method, along with the Average Solvent Electrostatic Configuration and Free Energy Gradient (ASEC‐FEG) and Polarizable Continuum Model (PCM) to take into account water solvation effects. For both isolated and solvated species, the main photochemical event is initiated by the absorption of light from ground‐state to the bright 1(ππ* La) state, which undergoes barrierless evolution to its minimum energy region (1(ππ* La)min) without crossing any other potential energy surface (PES). Subsequently, the excess of energy is released through fluorescence. From the 1(ππ* La)min region, two radiationless decay pathways back to the initial ground state, mediated by two distinct conical intersections between the ground and 1(ππ* La) states, are found to be unlikely due to the presence of high energy barriers in both environments. Our results also indicate that the solvation effects are more pronounced when using the ASEC‐FEG method, which predicts larger structural and energy changes, especially concerning energetic barriers. Based on the free energy perturbation theory (FEP), a hypothetical thermodynamic cycle was devised, from which we infer that in an aqueous environment the N3 site is the most favorable for protonation. We also conclude that the 8H‐8AZADAP tautomer is responsible for the fluorescent band observed experimentally at 410 nm and elucidates the mechanism of phototautomerism. 10.1111/php.14045 http://onlinelibrary.wiley.com/termsAndConditions#vor |
| doi_str_mv | 10.1111/php.14045 |
| format | Artículo Open Access |
| id | wiley_oa_10_1111_php_14045 |
| institution | Wiley Open Access |
| license_str_mv | http://onlinelibrary.wiley.com/termsAndConditions#vor |
| publishDate | 2025 |
| publisher | Wiley |
| record_format | wiley_oa |
| spellingShingle | Excited state relaxation mechanisms and tautomerism effects in 2,6‐Diamino‐8‐Azapurine Leonardo M. F. Oliveira Danillo Valverde Gustavo Juliani Costa Antonio Carlos Borin Photochemistry and Photobiology Excited state relaxation mechanisms and tautomerism effects in 2,6‐Diamino‐8‐Azapurine Leonardo M. F. Oliveira Danillo Valverde Gustavo Juliani Costa Antonio Carlos Borin Photochemistry and Photobiology AbstractThe photochemistry of 9H‐2,6‐diamino‐8‐azapurine (9H‐8AZADAP), a promising fluorescent probe, was investigated using the Multi‐State Complete‐Active‐Space Second‐Order Perturbation Theory (MS‐CASPT2) quantum chemical method, along with the Average Solvent Electrostatic Configuration and Free Energy Gradient (ASEC‐FEG) and Polarizable Continuum Model (PCM) to take into account water solvation effects. For both isolated and solvated species, the main photochemical event is initiated by the absorption of light from ground‐state to the bright 1(ππ* La) state, which undergoes barrierless evolution to its minimum energy region (1(ππ* La)min) without crossing any other potential energy surface (PES). Subsequently, the excess of energy is released through fluorescence. From the 1(ππ* La)min region, two radiationless decay pathways back to the initial ground state, mediated by two distinct conical intersections between the ground and 1(ππ* La) states, are found to be unlikely due to the presence of high energy barriers in both environments. Our results also indicate that the solvation effects are more pronounced when using the ASEC‐FEG method, which predicts larger structural and energy changes, especially concerning energetic barriers. Based on the free energy perturbation theory (FEP), a hypothetical thermodynamic cycle was devised, from which we infer that in an aqueous environment the N3 site is the most favorable for protonation. We also conclude that the 8H‐8AZADAP tautomer is responsible for the fluorescent band observed experimentally at 410 nm and elucidates the mechanism of phototautomerism. 10.1111/php.14045 http://onlinelibrary.wiley.com/termsAndConditions#vor |
| title | Excited state relaxation mechanisms and tautomerism effects in 2,6‐Diamino‐8‐Azapurine |
| topic | Photochemistry and Photobiology |
| url | https://onlinelibrary.wiley.com/doi/10.1111/php.14045 |