Highly Fluorescent Red-Light Emitting Bis(boranils) Based on Naphthalene Backbone

Abstract

Ten bis(boranils) differently substituted at the boron atom and iminophenyl groups were synthesized from 1,5-dihydroxynaphthalene-2,6-dicarboxaldehyde using a simple one-pot protocol. Their photophysical properties can be easily tuned in a wide range by the variation of substituents. Their absorption and emission spectral bands are significantly red-shifted (λ = 495-590 nm, λ = 533-683 nm) when compared with simple boranils, whereas fluorescence quantum yields are strongly improved to reach 83%. The attachment of pendant NO and NEt groups at the opposite positions of the π-conjugated bis(boranil) scaffold resulted in the formation of an unprecedented system featuring push-pull architecture.

Azabora[5]helicene Charge‐Transfer Dyes Show Efficient and Spectrally Variable Circularly Polarized Luminescence

“…[18] Much effort has been dedicated to the development of synthetically flexible platforms which enablet he photophysical fine-tuning of the dyes. [3,[9][10][11][19][20][21][22][23][24][25][26][27] As parto fo ur own research program we have developed borylated arylisoquinoline (BAI) dyes,w hich in their N,C-chelate variant are strongly emitting, solvatochromic, and two-photon-absorbing charge-transfer fluorophores with applicationp otentiali nb ioimaging. [9,10,28] With the idea to further enricht he photophysicso ft his fascinating platform we have built on their biaryl structure,w hich providesameanst oa rrive at dyes with helical chirality and the correspondingo bservation of interesting chiropticalp roperties, including the detection of circularly polarized luminescence (CPL).…”

“…Four‐coordinate organoboron chelates are attractive targets for the design of photostable fluorescent dyes for the most varied applications, including bioimaging, sensing, and organic light‐emitting diodes . Much effort has been dedicated to the development of synthetically flexible platforms which enable the photophysical fine‐tuning of the dyes . As part of our own research program we have developed borylated arylisoquinoline (BAI) dyes, which in their N,C‐chelate variant are strongly emitting, solvatochromic, and two‐photon‐absorbing charge‐transfer fluorophores with application potential in bioimaging .…”

Bio-Inspired Artificial Light-Harvesting Arrays Based on Boron(III)-Chelates

“…Unfortunately, the fluorescence quantum yields tend to be low, at least in solution, and thereby restrict the application of the compounds as solar concentrators. This is not the case for the rigid naphthyl-bridged binuclear complexes shown in Figure 11 where emission quantum yields can approach 90% [17]. One added advantage of these simple chelates is the ability to synthesise optically resolved fluorophores in good yield.…”

Design of Two‐Photon‐Excited Fluorescent Dyes Containing Fluoroborylene Groups

“…These systems can be divided into to 3 major categories, following their architectures: D‐A ( 1 ), D‐A‐D ( 2 – 4 ) and D‐A‐A‐D ( 5 ). Our interest in this class of fluorescent dyes, including such representative families as BODIPY, aza‐BODIPY, boranils, HBO and difluoroboron β‐diketonate complexes, stems from their excellent photostability, ease of functionalization and high fluorescence quantum yields. As highlighted above, the latter property is crucial for bioimaging applications.…”