15875-49-7Relevant academic research and scientific papers
Photoswitching using visible light: A new class of organic photochromic molecules
Helmy, Sameh,Leibfarth, Frank A.,Oh, Saemi,Poelma, Justin E.,Hawker, Craig J.,De Alaniz, Javier Read
, p. 8169 - 8172 (2014)
A versatile new class of organic photochromic molecules that offers an unprecedented combination of physical properties including tunable photoswitching using visible light, excellent fatigue resistance, and large polarity changes is described. These uniq
Unraveling the Photoswitching Mechanism in Donor-Acceptor Stenhouse Adducts
Lerch, Michael M.,Wezenberg, Sander J.,Szymanski, Wiktor,Feringa, Ben L.
, p. 6344 - 6347 (2016)
Molecular photoswitches have opened up a myriad of opportunities in applications ranging from responsive materials and control of biological function to molecular logics. Here, we show that the photoswitching mechanism of donor-acceptor Stenhouse adducts (DASA), a recently reported class of photoswitches, proceeds by photoinduced Z-E isomerization, followed by a thermal, conrotatory 4π-electrocyclization. The photogenerated intermediate is manifested by a bathochromically shifted band in the visible absorption spectrum of the DASA. The identification of the role of this intermediate reveals a key step in the photoswitching mechanism that is essential to the rational design of switching properties via structural modification.
It's a Trap: Thiol-Michael Chemistry on a DASA Photoswitch
Alves, Jessica,Barner-Kowollik, Christopher,Blinco, James P.,Gr?fe, David,Walden, Sarah L.,Wiedbrauk, Sandra
, p. 809 - 813 (2020)
Donor–acceptor Stenhouse adducts (DASA) are popular photoswitches capable of toggling between two isomers depending on the light and temperature of the system. The cyclized polar form is accessed by visible-light irradiation, whereas the linear nonpolar f
Visible Light-Controlled Inversion of Pickering Emulsions Stabilized by Functional Silica Microspheres
Chen, Yongkui,Li, Zhiyong,Wang, Huiyong,Pei, Yuanchao,Shi, Yunlei,Wang, Jianji
, p. 2784 - 2790 (2018)
A new class of donor-acceptor Stenhouse adduct (DASA)-functionalized silica microspheres (SMs) is designed and described to formulate Pickering emulsions with inversion property and large polarity change upon visible light irradiation. By tuning the hydrophilicity of the functional SM particles with visible light, these Pickering emulsions can easily perform inversion from water-in-oil to oil-in-water. The inversion performance of the emulsions is ascribed to DASA photoisomerization from an extended, hydrophobic, and intensely purple-colored triene to a compact, zwitterionic, and colorless cyclopentenone upon irradiation with visible light. This unique inversion behavior has been applied to control encapsulation and the release of fluorescein sodium salt.
New donor-acceptor stenhouse adducts as visible and near infrared light polymerization photoinitiators
Bonardi, Aude-Héloise,Dumur, Frédéric,Duval, Sylvain,Gigmes, Didier,Lalevée, Jacques,Noirbent, Guillaume,Xu, Yangyang
, (2020)
Polymerization photoinitiators that can be activated under low light intensity and in the visible range are being pursued by both the academic and industrial communities. To efficiently harvest light and initiate a polymerization process, dyes with high molar extinction coefficients in the visible range are ideal candidates. In this field, Donor-acceptor Stenhouse Adducts (DASA) which belong to a class of recently discovered organic photochromic molecules still lack practical applications. In this work, a series of DASA-based dyes are proposed as photoinitiators for the free radical polymerization of (meth)acrylates upon exposure to a near infrared light (laser diode at 785 nm).
Tunable Visible and Near Infrared Photoswitches
Hemmer, James R.,Poelma, Saemi O.,Treat, Nicolas,Page, Zachariah A.,Dolinski, Neil D.,Diaz, Yvonne J.,Tomlinson, Warren,Clark, Kyle D.,Hooper, Joseph P.,Hawker, Craig,Read De Alaniz, Javier
, p. 13960 - 13966 (2016)
A class of tunable visible and near-infrared donor-acceptor Stenhouse adduct (DASA) photoswitches were efficiently synthesized in two to four steps from commercially available starting materials with minimal purification. Using either Meldrum's or barbitu
Design and synthesis of donor-acceptor stenhouse adducts: A visible light photoswitch derived from furfural
Helmy, Sameh,Oh, Saemi,Leibfarth, Frank A.,Hawker, Craig J.,Read De Alaniz, Javier
, p. 11316 - 11329 (2014)
The development of an easily synthesized, modular, and tunable organic photoswitch that responds to visible light has been a long-standing pursuit. Herein we provide a detailed account of the design and synthesis of a new class of photochromes based on fu
A readily accessible porous organic polymer facilitates high-yielding Knoevenagel condensation at room temperature both in water and under solvent-free mechanochemical conditions
Sarma, Parishmita,Sarmah, Kashyap Kumar,Kakoti, Dharittri,Mahanta, Sanjeev Pran,Adassooriya, Nadeesh Madusanka,Nandi, Goutam,Das, Pranab Jyoti,Bu?ar, Dejan-Kre?imir,Thakuria, Ranjit
, (2021)
A novel nitrogen-rich amorphous porous organic polymer has been synthesized using a microwave-assisted process. Its high chemical stability, reusability and poor solubility enable the use of the porous polymer as a metal-free heterogeneous catalyst for C–
Taming the complexity of donor-acceptor stenhouse adducts: Infrared motion pictures of the complete switching pathway
Zulfikri, Habiburrahman,Koenis, Mark A. J.,Lerch, Michael M.,Di Donato, Mariangela,Szymański, Wiktor,Filippi, Claudia,Feringa, Ben L.,Buma, Wybren Jan
, p. 7376 - 7384 (2019)
Switches that can be actively steered by external stimuli along multiple pathways at the molecular level are the basis for next-generation responsive material systems. The operation of commonly employed molecular photoswitches revolves around one key structural coordinate. Photoswitches with functionalities that depend on and can be addressed along multiple coordinates would offer novel means to tailor and control their behavior and performance. The recently developed donor-acceptor Stenhouse adducts (DASAs) are versatile switches suitable for such applications. Their photochemistry is well understood, but is only responsible for part of their overall photoswitching mechanism. The remaining thermal switching pathways are to date unknown. Here, rapid-scan infrared absorption spectroscopy is used to obtain transient fingerprints of reactions occurring on the ground state potential energy surface after reaching structures generated through light absorption. The spectroscopic data are interpreted in terms of structural transformations using kinetic modeling and quantum chemical calculations. Through this combined experimental-theoretical approach, we are able to unravel the complexity of the multidimensional ground-state potential energy surface explored by the photoswitch and use this knowledge to predict, and subsequently confirm, how DASA switches can be guided along this potential energy surface. These results break new ground for developing user-geared DASA switches but also shed light on the development of novel photoswitches in general.
Shedding Light on the Photoisomerization Pathway of Donor-Acceptor Stenhouse Adducts
Di Donato, Mariangela,Lerch, Michael M.,Lapini, Andrea,Laurent, Adèle D.,Iagatti, Alessandro,Bussotti, Laura,Ihrig, Svante P.,Medved, Miroslav,Jacquemin, Denis,Szymański, Wiktor,Buma, Wybren Jan,Foggi, Paolo,Feringa, Ben L.
, p. 15596 - 15599 (2017)
Donor-acceptor Stenhouse adducts (DASAs) are negative photochromes that hold great promise for a variety of applications. Key to optimizing their switching properties is a detailed understanding of the photoswitching mechanism, which, as yet, is absent. Here we characterize the actinic step of DASA-photoswitching and its key intermediate, which was studied using a combination of ultrafast visible and IR pump-probe spectroscopies and TD-DFT calculations. Comparison of the time-resolved IR spectra with DFT computations allowed to unambiguously identify the structure of the intermediate, confirming that light absorption induces a sequential reaction path in which a Z-E photoisomerization of C2-C3 is followed by a rotation around C3-C4 and a subsequent thermal cyclization step. First and second-generation DASAs share a common photoisomerization mechanism in chlorinated solvents with notable differences in kinetics and lifetimes of the excited states. The photogenerated intermediate of the second-generation DASA was photo-accumulated at low temperature and probed with time-resolved spectroscopy, demonstrating the photoreversibility of the isomerization process. Taken together, these results provide a detailed picture of the DASA isomerization pathway on a molecular level.
