Slovak
Albanian
Arabic
Armenian
Azerbaijani
Belarusian
Bengali
Bosnian
Catalan
Czech
Danish
Deutsch
Dutch
English
Estonian
Finnish
Français
Greek
Haitian Creole
Hebrew
Hindi
Hungarian
Icelandic
Indonesian
Irish
Italian
Japanese
Korean
Latvian
Lithuanian
Macedonian
Mongolian
Norwegian
Persian
Polish
Portuguese
Romanian
Russian
Serbian
Slovak
Slovenian
Spanish
Swahili
Swedish
Turkish
Ukrainian
Vietnamese
Български
中文(简体)
中文(繁體)
Journal of Organic Chemistry 2008-Jan

Bichromophoric photochromes based on the opening and closing of a single oxazine ring.

Články môžu prekladať iba registrovaní používatelia
Prihlásiť Registrácia
Odkaz sa uloží do schránky
Massimiliano Tomasulo
Salvatore Sortino
Françisco M Raymo

Kľúčové slová

Abstrakt

We have designed bichromophoric photochromes based on the photoinduced opening and thermal closing of a [1,3]oxazine ring. In particular, we have synthesized six compounds incorporating fused 3H-indole and 4-nitrophenoxy fragments and pendant biphenyl, styryl, biphenylvinyl, or stilbenylvinyl groups. The laser excitation of two of these six molecules cleaves a [C-O] bond and opens their [1,3]oxazine ring in less than 6 ns with quantum yields of 0.08 and 0.28, respectively. This photoinduced process generates simultaneously a 4-nitrophenolate anion and a 3H-indolium cation. Both chromophores absorb in the same region of the electromagnetic spectrum. As a result, an intense band appears at ca. 440 nm upon the photoinduced opening of the [1,3]oxazine ring. In both instances, the photogenerated species switches back to the original isomer with first-order kinetics and lifetimes of 38 and 140 ns, respectively. Both compounds have excellent fatigue resistances and retain their photochemical behavior within rigid poly(methyl methacrylate) matrices. However, the thermal reisomerization within the polymer matrix is significantly slower and requires several microseconds to occur. The other four compounds do not undergo ring opening upon excitation under otherwise identical experimental conditions. Indeed, either photoinduced electron transfer or intersystem crossing compete successfully with the ring-opening process.

Pripojte sa k našej
facebookovej stránke

Najkompletnejšia databáza liečivých bylín podporovaná vedou

  • Pracuje v 55 jazykoch
  • Bylinné lieky podporené vedou
  • Rozpoznávanie bylín podľa obrázka
  • Interaktívna GPS mapa - označte byliny na mieste (už čoskoro)
  • Prečítajte si vedecké publikácie týkajúce sa vášho hľadania
  • Vyhľadajte liečivé byliny podľa ich účinkov
  • Usporiadajte svoje záujmy a držte krok s novinkami, klinickými skúškami a patentmi

Zadajte príznak alebo chorobu a prečítajte si o bylinách, ktoré by vám mohli pomôcť, napíšte bylinu a pozrite sa na choroby a príznaky, proti ktorým sa používa.
* Všetky informácie sú založené na publikovanom vedeckom výskume

Google Play badgeApp Store badge