Synthesis, Structure, and Properties of Near‐Infrared [b]Phenanthrene‐Fused BF₂ Azadipyrromethenes

Abstract

A new class of phenanthrene-fused BF azadipyrromethene (azaBODIPY) dyes have been synthesized through a tandem Suzuki reaction and oxidative ring-fusion reaction, or a palladium-catalyzed intramolecular C-H activation reaction. These phenanthrene-fused azaBODIPY dyes are highly photostable and display markedly redshifted absorption (up to λ=771 nm) and emission bands (λ≈800 nm) in the near-infrared region. DFT calculations and cyclic voltammetry studies indicate that, upon annulation, more pronounced stabilization of the LUMO is the origin of the bathochromic shift of the absorption and high photostability.

Synthetic Applications of Oxidative Aromatic Coupling—From Biphenols to Nanographenes

“…Intramolecular oxidative coupling has also been used as ac onvenient procedure for the ring fusion of perylene diimides (PDI), [172][173][174] as well as for p-expansions of BODIPY and aza-BODIPY-based dyes, [175][176][177][178][179] which has led to significant bathochromic shifts of the absorption and emission maxima. Al ibrary of p-expanded imidazoles has been prepared by employing aPIFA/BF 3 ·Et 2 Osystem for the oxidative cyclization of variously substituted 1,2,4,5-tetraarylimidazole derivatives.…”

Syntheseanwendungen der oxidativen aromatischen Kupplung – von Biphenolen zu Nanographenen

“…Die intramolekulare oxidative Kupplung wurde auch als geeignetes Verfahren für die Ringfusion von Perylendiimiden (PDIs) sowie für π‐Expansionen von BODIPY‐ und AzaBODIPY‐basierten Farbstoffen verwendet, was zu signifikanten bathochromen Verschiebungen von Absorptions‐ und Emissionsmaxima führt. Eine Bibliothek π‐expandierter Imidazole wurde unter Verwendung eines PIFA/BF 3 ⋅Et 2 O‐Systems für die oxidative Cyclisierung verschieden substituierter 1,2,4,5‐Tetraarylimidazolderivate erstellt …”

A Palette of Efficient and Stable Far-Red and NIR Dye Lasers

“…(3) The replacement of the meso carbon by an aza group (aza-BODIPY) [41][42][43]. Such simple modification induces pronounced bathocromic shifts [44], which can be enlarged spanning the delocalize π-system, as in the preceding point.…”