Fluoreszenzfarbstoffe mit großen Stokes‐Shifts – eine einfache Synthese von [2,2′‐Bipyridin]‐3,3′‐diol

Abstract

[2,2′‐Bipyridin]‐3,3′‐diol (4) wird aus Furoin (8) in einem Schritt über die Zincke‐Umlagerung in 32proz. Ausbeute erhalten. Die Fluoreszenzquantenausbeute des Farbstoffs beträgt in Chloroform 50% – Absorptions‐ und Fluoreszenzspektrum sind vollständig getrennt (TZ  1011). Für den großen Stokes‐Shift ist ein intramolekularer Protonentransfer nach dem Förster‐ Mechanismus verantwortlich.

Labelling of liposomes with intercalating perylene fluorescent dyes

“…The perylene dyes are prepared from perylene-3,4:9,10-tetracarboxylic bisanhydride, the corresponding amine or amine hydrochloride and imidazole ac-cording to literature procedure [4][5][6][7][8][9]. Special care is taken to prepare highly pure dyes.…”

Luminescent Excited‐State Intramolecular Proton‐Transfer (ESIPT) Dyes Based on 4‐Alkyne‐Functionalized [2,2′‐Bipyridine]‐3,3′‐diol Dyes

“…Such a structural change agrees with the ultrafast excited-state intramolecular-proton-transfer process from the Franck-Condon state, which is typical of such species. [6,11,12] As for the absorption maxima (see above), the emission maxima of 3-5 are redshifted compared with those of 1 and 2 as a consequence of the presence of the alkynyl substituents. Such a red shift is more significant for compound 5, which contains the terpyridine moiety.…”

“…From the examples found in the literature, such as salicylates, [3] O-hydroxyphenyl pyridine, [4] or O-hydroxyphenyl benzothiazole, [5] we focused our attention on functionalized 2,2'-bipyridyl-3,3'-diols. [6] This choice was moAbstract: Functionalized 6,6'-dimethyl-3,3'-dihydroxy-2,2'-bipyridine dyes (BP(OH) 2 ) exhibit relatively intense fluorescence from the relaxed excited state formed by excited-state intramolecular proton transfer (ESIPT). Bromo functionalization of (BP(OH) 2 ) species followed by palladium(0)-catalyzed reactions allows the connection (via alkyne tethers) of functional groups, such as the singlet-emitter diazaboraindacene (bodipy) group or a chelating module (terpyridine; terpy).…”

X-ray and spectroscopic investigation of 2-(2-hydroxyphenyl)pyridine-1-oxide

“…3). Although the distances between the planes of the tings are as large as 3.80(1) ,~, it is believed that this kind of stacking brings about a change of the molecular electron distribution (Langhals, 1986), and thus can be responsible for the intense green colour of the crystals of 2.…”