Mix and Match Tuning of the Conformational and Multistate Redox Switching Properties of an Overcrowded Alkene

Journal of the American Chemical Society, Journal Year: 2024, Volume and Issue: unknown

Published: Sept. 13, 2024

Overcrowded alkenes have received considerable attention as versatile structural motifs in a range of optical switches and light-driven unidirectional motors. In contrast, their actuation by electrochemical stimuli remains underexplored, even though this alternative energy input may be preferred various applications enables additional control over molecular switching states properties. While symmetric bistricyclic overcrowded enes (BAEs) containing two identical halves based on either thioxanthene (TX) or acridine (Acr) are known to reversible conformational redox switches, potentials generally too high low, respectively, thereby preventing wider applications. Herein, we demonstrate that the "mixed" TX-Acr switch possesses properties lie between those its parent analogs, enabling interconversion three stable at mild potentials. This includes neutral

Language: Английский

Recent Advances in NIR‐Switchable Multi‐Redox Systems Based on Organic Molecules

Chemistry - A European Journal, Journal Year: 2024, Volume and Issue: unknown

Published: Nov. 6, 2024

Abstract Electrochromic systems capable of switching absorption in the near‐infrared (NIR) region (750–2500 nm) are attractive from viewpoint applications for material and life science, thus several examples have been reported to date. In general, development organic‐based is needed reduce environmental impact improve biocompatibility. Although extending switchable spectral range crucial application organic electrochromic molecules, NIR based on redox interconversion still a challenging issue regarding reversibility durability during interconversion. To overcome this potential instability, introduction heteroatoms into molecular backbone and/or π‐extension could be useful strategies terms effective delocalization charge spin corresponding states. review, we focus redox‐active well‐defined small molecules that enable ON/OFF precise control states, present recent studies their intrinsic electrochemical spectroscopic properties structural characterization charged

Language: Английский

Electron‐deficient Indenofluorene‐based Systems: Multicolor and Visible‐to‐near‐infrared (NIR) Electrochromism and OFF‐OFF‐ON Electrofluorochromism

Chemistry - An Asian Journal, Journal Year: 2024, Volume and Issue: unknown

Published: Oct. 29, 2024

Abstract Multifunctional electrochromic systems with divergent functions are highly sought after but rare and challenging to develop. Here, we report the synthesis multi‐functional behaviour (multi‐colour modulation, visible‐to‐near IR absorption switching, electrofluorochromism) of electron‐deficient indenofluorene‐based systems. The compounds ( IF 1 ‐IF 5 ) have been obtained via Knoevenagel condensation indenofluorenone K various nucleophiles (malononitrile, benzylcyanide, dimethyl malonate, methyl cyanoacetate, benzothiazole‐2‐acetonitrile). possess strong colours absorb in visible region (λ max =295–388 nm). These electroactive exhibit two reversible reduction waves (−0.35–−0.88 V −0.65–−1.30 vs Ag/AgCl), generating radical anion dianion For studies, upon applying one‐electron potential (−0.35 maximum redshift from 382 nm 1240 − ⋅), which subsequently blueshifts 466 & 745 (IF 2 ⋅ increasing two‐electron (−0.65 Ag/AgCl). color solution was switched green dark blue further light orange. is cycling. In addition, unlike non‐fluorescent , reduced system red‐emissive em =630 nm) due combination radicals leading formation antiaromatic quinoidal π‐conjugated .

Language: Английский