1,3,3-Trimethylindolino-6'-nitrobenzopyrylospiran (SP-1) as an example of a photoswitchable spiropyran was loaded into the pores of different prototypical metal-organic frameworks, namely MOF-5, MIL-68(In), and MIL-68(Ga), by a vapor-phase process. The successful incorporation in the pores of the MOF was proven by X-ray powder diffraction, and the amount of the embedded photoswitchable guest was determined by X-ray photoelectron spectroscopy and elemental analysis. In contrast to the sterically hindered crystalline state, SP-1 embedded in solid MOF hosts shows photoswitching under irradiation with UV light from the spiropyran to its merocyanine form with a nearly complete photoisomerization. Switching can be reversed by heat treatment. These switching properties were confirmed by means of UV/vis and IR spectroscopy. Remarkably, the embedded guest molecules show photoswitching and absorption properties similar to those in the dissolved state, so that MOFs might be considered as "solid solvents" for photoswitchable spiropyrans. In contrast to that, embedment of SP-1 in the smaller pores of MIL-53(Al) was not successful. SP-1 is mainly adsorbed on the surfaces of the MIL-53(Al) particles, which also leads to photoswitching properties.
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http://dx.doi.org/10.1021/acs.inorgchem.7b01908 | DOI Listing |
Org Lett
December 2024
Macromolecular Chemistry, Institute of Chemistry, Faculty of Natural Science II, Martin Luther University Halle Wittenberg, von-Danckelmann-Platz 4, 06120 Halle, Germany.
RSC Adv
November 2024
Department of Organic Chemistry, University of Chemistry and Technology Prague Technická 5, Prague 6 Prague 166 28 Czech Republic
Three series of spiropyran photoswitches with an auxiliary chiral centre at position 3' of the indoline unit were synthesized. Using one example, a novel methodology for synthesis of an optically active spiropyran photoswitch with a defined chirality at position 3' is demonstrated. Furthermore, a new acid-mediated strategy for spiropyran purification affording moderate to excellent yields (up to 96%) is reported herein.
View Article and Find Full Text PDFJ Colloid Interface Sci
January 2025
Faculty of Polymer Engineering, Sahand University of Technology, P.O. Box 51335-1996, Tabriz, Iran; Institute of Polymeric Materials, Sahand University of Technology, P.O. Box 51335-1996, Tabriz, Iran.
Angew Chem Int Ed Engl
January 2025
School of Chemical Sciences, University of Chinese Academy of Sciences (UCAS), 100049, Beijing, P. R. China.
We have developed a new type of nanoparticles with potent antitumor activity photoactivatable via the combination of molecular photoswitching of spiropyran (SP) and enzymatic reaction of glucose oxidase (GOx). As two key processes involved therein, Fe(III)-to-Fe(II) photoreduction in Fe(III) metal-organic frameworks (MOFs) brings about the release of free Fe/Fe while the photoswitching of SP to merocyanine (MC) unlocks the enzymatic activity of GOx that was pre-passivated by SP. The release of free Fe boosts its hydrolysis and therefore enables the acidification of microenvironment, which is further reinforced by one of the products of the GOx-mediated glucose oxidation reaction, gluconic acid (GlcA).
View Article and Find Full Text PDFACS Nano
October 2024
Department of Applied Chemistry, National Yang Ming Chiao Tung University, 300093 Hsinchu, Taiwan.
Artificial photomodulated channels represent a significant advancement toward practical photogated systems because of their remote noncontact stimulation. Ion transport behaviors in artificial photomodulated channels, however, still require further investigation, especially in multiple nanochannels that closely resemble biological structures. Herein, we present the design and development of photoswitchable ion nanochannels inspired by natural channelrhodopsins (ChRs), utilizing photoresponsive polymers grafted anodic aluminum oxide (AAO) membranes.
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