Photostable NIR‐II Pigments from Extended Rylenecarboximides

Abstract

A series of near-infrared (NIR) organic absorbers, named FNs and FPs, have been obtained with absorption maxima from 870 nm to 1100 nm and thus falling into the attractive second near-infrared region (NIR-II). The synthesis of their extended aromatic cores utilized an initial arylamination between 4-aminonaphthalene-1,8-dicarboximide (NMI-NH 2 ) or 9-aminoperylene-3,4-dicarboximide (PMI-NH 2 ) with chloro-substituted 9,10-anthraquinones followed by a novel base-induced cyclodehydrogenation. A NIR-II pigment, compound FPP, was obtained through de-alkylation of a soluble precursor. The synthesis of this photostable pigment is high-yielding and avoids column chromatographic purification which is important for many applications.

A Terrylene–Anthraquinone Dyad as a Chromophore for Photothermal Therapy in the NIR-II Window

“…Compared with precursor TQ, FTQ revealed a pronounced bathochromic shift of 442 nm, reflecting the significantly extended π-conjugation after dehydrocyclization. Importantly, in comparison with the NMI (λ max = 872 nm) and PMI fused analogues (λ max = 1028 nm), 18 extending the conjugation to FTQ induced further red-shifted absorption, displaying λ max at 1140 nm and an intense absorption peak (λ 1 ) at 837 nm with molar absorption coefficients of 17,628 and 54,833 M −1 cm −1 , respectively.…”

“…Rylene dicarboximides (Figure 1) are considered as a promising candidate due to their exceptional stability and high photothermal conversion efficiency (PCE). 17 In our recent study, 18 we have introduced a series of novel NIR chromophores based on anthraquinone fused with naphthalene-1,8-dicarboximide (FNQ) and perylene-3,4-dicarboximide (FPQ), which demonstrate maximum absorption peaks (λ max ) above 720 nm. However, to achieve the PTT effect in the NIR-II window, further improvement of the absorption domain and processability is urgently required.…”

Synthesis and Characterization of Quinone Compounds Derived from Doubly and Triply Linked Diporphyrins and Tuning of Their Absorption Properties**

“…This occurred probably because of the protonation or metalation of 2 , as suggested by the fact that the solution color of 2 changed from green to black upon the addition of Sc(OTf) 3 . Therefore, we synthesized free base 3 under basic conditions that are frequently used for the synthesis of expanded rylenebisimides (Scheme 1b) [28–30] . In fact, treatment of 2 with K 2 CO 3 in ethanolamine at 130 °C afforded 3 in 32 % yield.…”

“…Therefore, we synthesized free base 3 under basic conditions that are frequently used for the synthesis of expanded rylenebisimides (Scheme 1b). [28][29][30] In fact, treatment of 2 with K 2 CO 3 in ethanolamine at 130 °C afforded 3 in 32 % yield.…”

Rigid and Photostable Shortwave Infrared Dye Absorbing/Emitting beyond 1200 nm for High-Contrast Multiplexed Imaging

“…Additionally, long-wavelength dyes, particularly cyanine dyes, are potentially susceptible to vibration- or solvent-induced symmetry breaking, resulting in the loss of cyanine characters . Many also exhibit collateral absorption in the visible range from S 0 to S n , which induces discoloration of the surgical field of view . To date, robust organic fluorochromes for the blue end of the NIR spectral region of 650–800 nm are abundant .…”