16650-15-0Relevant articles and documents
Femtosecond UV/mid-IR study of photochromism of the spiropyran 1′,3′-dihydro-1′,3′,3′-trimethyl-6- nitrospiro[2H-1-benzopyran-2,2′-(2H)-indole] in solution
Holm, Ann-Kathrin,Rini, Matteo,Nibbering, Erik T.J.,Fidder, Henk
, p. 214 - 219 (2003)
The ring-opening reaction of 1′,3′- dihydro-1′,3′,3′- trimethyl-6-nitrospiro[2H-1-benzopyran-2,2′-(2H)-indole] is investigated in two solvents, by probing the evolution of the vibrational absorption spectrum with 130 fs time-resolution. Competition betwee
Distinct influence of the anion and ether group on the polarity of ammonium and imidazolium ionic liquids
Zhang, Shiguo,Chen, Zhengjian,Qi, Xiujuan,Deng, Youquan
, p. 1043 - 1050 (2012)
The polarity of ionic liquids (ILs), usually denoted as ET(30) by the solvatochromic probe Reichardt's dye, is one of the most fundamental properties that remarkably affect the solvation and chemical reaction in ILs. It was generally accepted that the ET(30) of ILs was dominated by the nature of the cation. However, in this work, it was found that the common ammonium-based ILs showed strongly anion-dependent ET(30). For example, the ET(30) value for [N1124][DCA] and [N 1124][NTf2] is 49.0 and 59.0 kcal mol-1, respectively, while the corresponding imidazolium ILs bearing the same anions possess nearly identical ET(30), the ET(30) value for [BMIm][DCA] and [BMIm][NTf2] is 51.4 and 51.6 kcal mol-1, respectively. Moreover, introduction of an ether group was found to increase the ET(30) of imidazolium ILs while having no obvious effect on that of ammonium-based ILs. The Kamlet-Taft parameters and density functional theory (DFT) calculations indicated that the distinct result is related to different stabilization of the ground state of Reichardt's dye 30. In imidazolium ILs, the main interactions between ILs and zwitterionic dye involve both coulombic interaction (between the cation and the phenolate oxygen atom) and H-bonding interaction (between the acidic hydrogen on imidazolium ring and the phenolate oxygen atom). However, with the ammonium ILs lack of active hydrogen, the dye is only stabilized by the coulombic interaction between the cation and the phenolate oxygen atom. Interestingly, in both imidazolium and ammonium-based ILs, the spiropyran-merocyanine equilibrium exhibit obvious anion-dependent photochromism, solvatochromism, and thermal relaxation. The Royal Society of Chemistry and the Centre National de la Recherche Scientifique 2012.
Reversing the thermal stability of a molecular switch on a gold surface: Ring-opening reaction of nitrospiropyran
Piantek, Marten,Schulze, Gunnar,Koch, Matthias,Franke, Katharina J.,Leyssner, Felix,Krueger, Alex,Navio, Cristina,Miguel, Jorge,Bernien, Matthias,Wolf, Martin,Kuch, Wolfgang,Tegeder, Petra,Pascual, Jose Ignacio
, p. 12729 - 12735 (2009)
The ring-opening/closing reaction between spiropyran (SP) and merocyanine (MC) is a prototypical thermally and optically induced reversible reaction. However, MC molecules in solution are thermodynamically unstable at room temperature and thus return to t
Spiropyran-conjugated thermoresponsive copolymer as a colorimetric thermometer with linear and reversible color change
Shiraishi, Yasuhiro,Miyamoto, Ryo,Hirai, Takayuki
, p. 1571 - 1574 (2009)
A simple copolymer, poly(NIPAM-co-SP), consisting of N-isopropylacrylamide and spiropyran units, behaves as a colorimetric thermometer exhibiting temperature-responsive linear and reversible bathochromic/hypsochromic shift of the absorption spectra under
Synthesis, optical properties and in vitro cell viability of novel spiropyrans and their photostationary states
Rastogi, Shiva K.,Zhao, Zhenze,Gildner, M. Brenton,Shoulders, Ben A.,Velasquez, Tara L.,Blumenthal, Madeleine O.,Wang, Lei,Li, Xiaopeng,Hudnall, Todd W.,Betancourt, Tania,Du, Liqin,Brittain, William J.
, (2021/01/06)
A novel class of spiropyran (SP) was synthesized using a multistep process that involves three key intermediates: (a) diazonium-tetrafluoroborate, (b) hydrazine and (c) indolium iodide. Single crystal X-ray spectroscopy was used to confirm the structure of one of the analogues. The SP analogues were confirmed as being able to isomerize and attain a photostationary state (PSS) upon irradiation with ultraviolet light (UV, 365 nm) in an aqueous environment. UV–visible absorption spectra were recorded to confirm the isomerization properties. The ability of the synthesized compounds to induce growth inhibition of HeLa cervical cancer cells was assessed via the MTT assay after incubation with either the SP or their PSS. The IC50 values of two PSS (PSS-2, 4), were observed to be around 14 ± 4 fold lower (26 ± 3 μM) than their corresponding SPs. The most cytotoxic compounds SP-7 and PSS-7 showed the lowest IC50 values (12 μM). An in vitro tubulin polymerization assay showed that SP-7 and PSS-7 exhibited the greatest difference in tubulin inhibition relative to unirradiated SP-1 and SP-4.
Combined In Situ Illumination-NMR-UV/Vis Spectroscopy: A New Mechanistic Tool in Photochemistry
Seegerer, Andreas,Nitschke, Philipp,Gschwind, Ruth M.
supporting information, p. 7493 - 7497 (2018/04/02)
Synthetic applications in photochemistry are booming. Despite great progress in the development of new reactions, mechanistic investigations are still challenging. Therefore, we present a fully automated in situ combination of NMR spectroscopy, UV/Vis spectroscopy, and illumination to allow simultaneous and time-resolved detection of paramagnetic and diamagnetic species. This optical fiber-based setup enables the first acquisition of combined UV/Vis and NMR spectra in photocatalysis, as demonstrated on a conPET process. Furthermore, the broad applicability of combined UVNMR spectroscopy for light-induced processes is demonstrated on a structural and quantitative analysis of a photoswitch, including rate modulation and stabilization of transient species by temperature variation. Owing to the flexibility regarding the NMR hardware, temperature, and light sources, we expect wide-ranging applications of this setup in various research fields.
Shining new light on the spiropyran photoswitch: A photocage decides between cis-trans or spiro-merocyanine isomerization
Fleming, Cassandra L.,Li, Shiming,Grotli, Morten,Andréasson, Joakim
supporting information, p. 14069 - 14072 (2018/10/31)
Photochromic molecules from the spiropyran family are known to undergo light-induced interconversion between the colorless spiro- and the colored merocyanine forms. Here, we show for the first time that small structural modifications open up for an additional photoisomerization mode: reversible cis-trans isomerization of the merocyanine. Moreover, the introduction of a photocage allows for light-activated switching between the two modes.
