Access to Strong Thieno[3,2-b]phosphole-Based Solid-State Emitters via Manganese(III)-Mediated Oxidative Annulation

Abstract

The synthesis of novel organic molecular frameworks with strong luminescence in the solid state has become an enormously growing area of current research due to their versatile applications for optoelectronics or bioimaging. Here, a facile synthetic strategy via Mn III -mediated oxidative annulation reaction to obtain propeller-rich molecules bearing a thieno[3,2-b]phosphole motif as a stator moiety is reported. All synthesized compounds show aggregation-induced emission (AIE) characteristics, strong fluorescence in the solid state, and substituentdependency of the photophysical properties. The phosphinated thieno[3,2-b]phospholes possess a high degree of restrictions on intramolecular motions, leading to powerful solid-state light emitters with fluorescence quantum yields close to 100% and lifetimes up to 7.9 ns, even at room temperature.

Illuminating the Path to Enhanced Bioimaging by Phosphole‐based Fluorophores

“…More detailed, compounds 2-5 and the dansyl variant 10 displayEC 50 values in the range of 1.8 to 3.5 nM comparable to the EC 50 value of the control peptide 1. The modification of the short NPY analogue [K 27 (Adm),P 30 ,K 31 ,Bip 32 ,L 34 ]-NPY (27)(28)(29)(30)(31)(32)(33)(34)(35)(36) with IPS-Cl 2 (7) at position K 31 led to an increased EC 50 value of 28 nM compared to 3 nM for the control peptide 6. Modification of [K 27 (Lau),P 30 ,K 31 ,Bip 32 ,L 34 ]-NPY (27)(28)(29)(30)(31)(32)(33)(34)(35)(36) with IPS-Cl 1 (9) was well tolerated regarding receptor activation and resulted in a decreased EC 50 value of 3 nM compared to 6 nM for the control peptide 8.…”

“…The modification of the short NPY analogue [K 27 (Adm),P 30 ,K 31 ,Bip 32 ,L 34 ]-NPY (27)(28)(29)(30)(31)(32)(33)(34)(35)(36) with IPS-Cl 2 (7) at position K 31 led to an increased EC 50 value of 28 nM compared to 3 nM for the control peptide 6. Modification of [K 27 (Lau),P 30 ,K 31 ,Bip 32 ,L 34 ]-NPY (27)(28)(29)(30)(31)(32)(33)(34)(35)(36) with IPS-Cl 1 (9) was well tolerated regarding receptor activation and resulted in a decreased EC 50 value of 3 nM compared to 6 nM for the control peptide 8. These findings clearly demonatrate that the introduction of IPS-Cl fluorophores does not influence the peptides' properties.…”

“…[21] These compounds show potential as efficient emitters in organic light-emitting diodes (OLEDs) owing to their unique characteristics. [22][23][24][25][26][27][28][29][30][31][32] Furthermore, phosphole-based fluorophores have already found practical applications in bioanalytics, specifically in biolabeling processes. [33,34] In the field of scientific investigation, pioneering research conducted by Yamaguchi et al in 2015 yielded groundbreaking advancements in the development of a photostable dye featuring a phosphole moiety.…”

Thieno[3,2-b]phosphole-based AIEgens: facile preparation and dual modulation of solid-state luminescence

“…65 Oxidative annulation with diphenylacetylene and Mn(OAc) 3 Á2H 2 O leads to the formation of 2. 63,[66][67][68] To demonstrate the potential of compound 2, we have previously conducted experiments involving Ni II -catalyzed cross-coupling 69 phosphination. 63 This methodology enabled the synthesis of highly efficient fluorophores, exhibiting solid-state quantum yields of up to 100%.…”

“…[52][53][54][55][56][57][58][59][60][61][62] In a recent study, we have described the successful synthesis of propeller-like thieno [3,2-b]phosphole oxides that demonstrate strong fluorescence in the solid state, coupled with significant dependence on substituents for their optical properties. 63 Building upon these findings, our current investigation capitalizes on this molecular framework to achieve emission tunability spanning into the red region of the visible light spectrum. This is accomplished through the strategic introduction of distinct substituents at the aand b-positions of the thiophene moiety.…”