855282-75-6Relevant articles and documents
Direct iodination of electron-deficient benzothiazoles: Rapid access to two-photon absorbing fluorophores with quadrupolar D-π-A-π-D architecture and tunable heteroaromatic core
Fakis, Mihalis,Georgiou, Dimitris,Hrobárik, Peter,Nociarová, Jela,Osusky, Patrik,Polyzos, Ioannis,Rakovsky, Erik
, p. 3460 - 3465 (2021/05/31)
Direct iodination of benzothiazoles under strong oxidative/acidic conditions leads to a mixture of iodinated heteroarenes with 1-2 major components, which are easily separable and which structures depend on the I2 equivalents used. Among the unexpected bu
Oxidative C-H Homocoupling of Push-Pull Benzothiazoles: An Atom-Economical Route to Highly Emissive Quadrupolar Arylamine-Functionalized 2,2′-Bibenzothiazoles with Enhanced Two-Photon Absorption
Fakis, Mihalis,Georgiou, Dimitris,Gyepes, Róbert,Hrobárik, Peter,Nociarová, Jela,Osusky, Patrik,Polyzos, Ioannis,Smolí?ek, Maro?
, p. 5512 - 5517 (2021/07/31)
Copper(II)-catalyzed C-H/C-H coupling of dipolar 2-H-benzothiazoles end-capped with triphenylamine moieties affords highly fluorescent 2,2′-bibenzothiazoles with quadrupolar (D-π-A-π-D) architecture displaying large two-photon absorption (TPA) cross sections (543-1252 GM) in the near-infrared region. The notably higher TPA performance as compared to quadrupolar π-systems with a widely used 2,2′-bipyridine core, along with the ease of the synthesis and chelating N^N ability, makes the title biheteroaryl platform an attractive building block for a large scope of functional dyes exploiting nonlinear optical phenomena.
Benzothiazole-based fluorophores of donor-π-acceptor-π-donor type displaying high two-photon absorption
Hrobarikova, Veronika,Hrobarik, Peter,Gajdos, Peter,Fitilis, Ioannis,Fakis, Mihalis,Persephonis, Peter,Zahradnik, Pavol
experimental part, p. 3053 - 3068 (2010/07/15)
A series of novel heterocycle-based dyes with donor-π-bridge-acceptor- π-bridge-donor (D-π-A-π-D) structural motif, where benzothiazole serves as an electron-withdrawing core, have been designed and synthesized via palladium-catalyzed Sonogashira and Suzuki-type cross-coupling reactions. All the target chromophores show strong one-photon and two-photon excited emission. The maximum two-photon absorption (TPA) cross sections ΔTPA of the prepared derivatives bearing diphenylamino functionalities occur at wavelengths ranging from 760 to 800 nm and are as large as ～900-1100 GM. One- and two-photon absorption characteristics of the title dyes have also been investigated by using density functional theory (DFT) and the structure-property relationships are discussed. The TPA cross sections calculated by means of quadratic response time-dependent DFT using the Coulomb-attenuated CAM-B3LYP functional support the experimentally observed trends within the series, as well as higher ΔTPA values of the title compounds compared to those of analogous fluorene or carbazole-derived dyes. In contrast, the traditional B3LYP functional was not successful in predicting the observed trend of TPA cross sections for systems with different central cores. In general, structural modification of the π-bridge composition by replacement of ethynylene (alkyne) with E-ethenylene (alkene) linkages and/or replacement of dialkylamino electron-donating edge substituents by diarylamino ones results in an increase of ΔTPA values. The combination of large TPA cross sections and high emission quantum yields makes the title benzothiazole-based dyes attractive for applications involving two-photon excited fluorescence (TPEF).
