Selektive Nah‐Infrarot‐Chromophore: Bis(pyrrolopyrrol)‐Cyanine

Abstract

Sehr unsichtbar: Bis(pyrrolopyrrol)‐Cyanine sind ausgedehnte Chromophore auf der Basis von Diketopyrrolopyrrolen (siehe allgemeine Struktur). Die Verbindungen zeigen eine sehr hohe, schmalbandige Absorption im Nah‐Infrarot(NIR)‐Bereich und intensive Fluoreszenz bei 1 μm. Da sie im sichtbaren Bereich fast nicht absorbieren, kommen sie dem Ideal eines selektiven NIR‐Absorbers nahe.

Bright Near‐Infrared Fluorophores Based on Squaraines by Unexpected Halogen Effects

“…Among the currently known brightest fluorophores with emission in the region above 700 nm are borondipyrromethenes (BODIPYs) and pyrrolopyrrole cyanines with emission maxima up to 780 and 966 nm, respectively. [5] Squaraine dyes are among the most promising candidates for NIR fluorophores because they show sharp and intense absorption in the long-wavelength region, and because of their rigid structure they possess good photostability. [6] Indeed, squaraines have already been applied in bioimaging, [7] and as sensitizers, therapeutic agents, and sensors for biological applications.…”

Structurally Tunable 3‐Cyanoformazanate Boron Difluoride Dyes

“…[1,2] The most common of these complexes [3] are produced via the coordination of boron difluoride [BF 2 ]…”

Bright Near‐Infrared Fluorophores Based on Squaraines by Unexpected Halogen Effects

“…[5] Squaraine dyes are among the most promising candidates for NIR fluorophores because they show sharp and intense absorption in the long-wavelength region, and because of their rigid structure they possess good photostability. The former addresses stability and reactivity of the chromophore within its application environment, whereas the latter feature approaches its contrast strength.…”