Ссылки

DOI

  • Ekaterina S. Starnovskaya
  • Maria I. Valieva
  • Aluru Rammohan
  • Dmitry S Kopchuk
  • Albert F Khasanov
  • Olga S Taniya
  • Alexander S. Novikov
  • Alexey Kalinichev
  • Sougata Santra
  • Grigory V Zyryanov
  • Brindaban Ranu
Push-pull fluorophores exhibiting pronounced intramolecular charge transfer have a low fluorescence quantum yield. Here we report a new series of D-π-A push-pull fluorophores containing a unified 2,2'-bipyridine domain acceptor with terminal electron donating carbazole/fluorene groups that exhibit good fluorescence performance. All fluorophores demonstrated high fluorescence quantum yields up to 0.99 and large Stokes shifts up to 10394 cm−1 (157 nm). For the first time, the solvatochromic method was successfully applied to 2,2'-bipyridine compounds of this type to evaluate their static and dynamic hyperpolarizability coefficients. Due to their remarkable fluorescence capability, two-photon emission cross sections were measured for three dyes using the two-photon fluorescence method. Both experimental studies and calculated charge transfer indices (CT-indices) confirmed the greatest charge separation in carbazole substituted isomers. The annelation of cyclopentene moiety to the 2,2'-bipyridine core inhibited the formation of aggregates in the solid state and significantly increased the energy gap. Finally, planarized ICT (PLICT) process was confirmed for fluorene-containing fluorophores based on theoretical calculations in the ground and excited states in various solvents. The synthesized carbazole-containing 2,2’-bipyridines are very promising ligands for constructing metallic NLO-phores, while fluorene-based fluorophores with a predominant PLICT state can be considered as promising environment polarity sensitive fluorescent dyes and biological probes to detect structural changes in proteins/biomolecular interactions and optical switches.
Язык оригиналаанглийский
Страницы (с-по)12393-12402
ЖурналNew Journal of Chemistry
Том47
Номер выпуска26
Дата раннего онлайн-доступа23 мая 2023
DOI
СостояниеОпубликовано - 2023

ID: 106484417