التفاصيل البيبلوغرافية
| العنوان: |
Red-Purple Photochromic Indigos from Green Chemistry: Mono‑ t BOC or Di‑ t BOC N ‑Substituted Indigos Displaying Excited State Proton Transfer or Photoisomerization |
| المؤلفون: |
Daniela Pinheiro (10645770), Adelino M. Galvão (5418908), Marta Pineiro (1694143), J. Sérgio Seixas de Melo (10645773) |
| سنة النشر: |
2021 |
| المجموعة: |
Smithsonian Institution: Digital Repository |
| مصطلحات موضوعية: |
Biophysics, Biochemistry, Ecology, Infectious Diseases, Virology, Environmental Sciences not elsewhere classified, Biological Sciences not elsewhere classified, Chemical Sciences not elsewhere classified, Physical Sciences not elsewhere classified, indigo, mol, NtBOCInd ESPT, Time-resolved fluorescence experiments, state proton transfer, deactivation routes, Different excited-state deactivatio., solvent-dependent, tert, dimer units, butoxy carbonyl groups, alternative ESPT, butoxycarbonyl, nonemissive cis conformation, time-resolved data, photoisomerization, Green Chemistry, radiationless deactivation, time-dependent density, Red-Purple Photochromic Indigos, nonpolar solvents |
| الوصف: |
In indigo, excited state proton transfer (ESPT) is known to be associated with the molecular mechanism responsible for highly efficient radiationless deactivation. When this route is blocked (partially or totally), new deactivation routes become available. Using new green chemistry procedures, with favorable green chemistry metrics, monosubstitution and disubstitution of N group(s) in indigo, by tert -butoxy carbonyl groups, N -( tert -butoxycarbonyl)indigo (NtBOCInd) and N,N′ -( tert -butoxycarbonyl)indigo (N,N’tBOCInd), respectively, were synthetically accomplished. The compounds display red to purple colors depending on the solvent and substitution. Different excited-state deactivation pathways were observed and found to be structure- and solvent-dependent. Trans–cis photoisomerization was found to be absent with NtBOCInd and present with N,N’tBOCInd in nonpolar solvents. Time-resolved fluorescence experiments revealed single-exponential decays for the two compounds which, linked to time-dependent density functional theory (TDDFT) studies, show that with NtBOCInd ESPT is extremely fast and barrierlesspredicted to be 1 kJ mol –1 in methylcyclohexane and 5 kJ mol –1 in dimethylsulfoxide, which contrasts with ∼11 kJ mol –1 experimentally obtained for indigo. An alternative ESPT, competitive with the N–H···OC intramolecular pathway, involving dimer units is also probed by TDDFT and found to be consistent with the experimentally observed time-resolved data. N,N’tBOCInd, where ESPT is precluded, shows solvent-dependent trans–cis / cis–trans photoisomerization and is surprisingly found to be more stable in the nonemissive cis conformation, whose deactivation to S 0 is found to be solvent-dependent. |
| نوع الوثيقة: |
article in journal/newspaper |
| اللغة: |
unknown |
| Relation: |
https://figshare.com/articles/journal_contribution/Red-Purple_Photochromic_Indigos_from_Green_Chemistry_Mono_i_t_i_BOC_or_Di_i_t_i_BOC_i_N_i_Substituted_Indigos_Displaying_Excited_State_Proton_Transfer_or_Photoisomerization/14414298 |
| DOI: |
10.1021/acs.jpcb.1c00120.s001 |
| الاتاحة: |
https://doi.org/10.1021/acs.jpcb.1c00120.s001 |
| Rights: |
CC BY-NC 4.0 |
| رقم الانضمام: |
edsbas.AD51BDB1 |
| قاعدة البيانات: |
BASE |