- Micellar-incorporated hydrogels with highly tough, mechanoresponsive, and self-recovery properties for strain-induced color sensors
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Tough, mechanoresponsive hydrogels have broad and significant impacts on fundamental research and practical applications, but have proved to be extremely challenging to develop. The poor solubility of mechanophores makes them difficult to be integrated into a highly hydrophilic network of hydrogels. In this work, we synthesized dimethylacrylate-functionalized spiropyran (SP) mechanophores and used them as crosslinkers to copolymerize with hydrophobic methyl acrylate (MA) monomers and hydrophilic acrylamide (AM) monomers in the presence of surfactant polysorbate 80 (TWEEN 80) micelles, forming poly(AM-co-MA/SP) hydrogels. The mechanical properties of the as-prepared and swollen poly(AM-co-MA/SP) hydrogels strongly depend on network components (AM, MA, and SP concentrations). Thus, the optimal hydrogels can achieve excellent mechanical properties (tensile stress of 1.1 MPa, tensile strain of 6 mm mm-1, elastic modulus of 1.1 MPa, and tearing energy of 3200 J m-2). Due to multi-stimuli responses of SP crosslinkers, the hydrogels exhibited the reversible changes in color and mechanical properties between the force-, heat-, and UV light-induced deformation state and the white light-induced recovery state. Based on their fast, reversible, force-induced color change behavior, we further designed a conceptual hydrogel strain sensor to monitor color change under the stretching and relaxing processes in multiple cycles. This work demonstrates that the presence of dynamically reversible SP crosslinkers and micellar structures is the key to greatly enhance both mechanical and color recoverable properties of poly(AM-co-MA/SP) hydrogels, which could serve as promising smart materials for a variety of applications such as soft robots, electronic skins, and strain/motion/damage sensors.
- Zhang, Yanxian,Ren, Baiping,Yang, Fengyu,Cai, Yongqing,Chen, Hong,Wang, Ting,Feng, Zhangqi,Tang, Jianxin,Xu, Jianxiong,Zheng, Jie
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Read Online
- Oxidative degradation of organic photochromes
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Photo-oxidation of some representative spiropyrans and spiro-oxazines does not seem to involve singlet oxygen O2(1Δg). The photochromes rather behave, in the spiro and merocyanine form, as O2(1Δg) quenchers. Only a methoxy-nitro benzopyran derivative was found to promote formation of singlet oxygen. Superoxide anion O2 is likely the activated oxygen species responsible for their oxidative photodegradation.
- Malatesta,Milosa,Millini,Lanzini,Bortolus,Monti
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Read Online
- Solvatochromic spiropyran - a facile method for visualized, sensitive and selective response of lead (Pb2+) ions in aqueous solution
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1′-(4′-carboxybutyl) ?3′, 3′-dimethyl-6-nitro-8-hydroxylspiro [chromene-2, 2′-indoline] (SPC) is a visual, selective, and sensitive detector to lead (Pb2+) ions. The presence of 8 -hydroxyl in pyran ring makes SPC have a remarkable solvatochrom
- Cui, Congcong,Gao, He,Gao, Jun,Li, Yiwei,Liu, Guojie,Wang, Jingbo,Wang, Min
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- Programmable Chromism and Photoluminescence of Spiropyran-Based Liquid Crystalline Polymer with Tunable Glass Transition Temperature
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Spiropyran-based materials (SPBMs) can give responses to the stimulations induced by the light, heat, force, or pH, which have been used as triggers for many smart materials. Here, a cross-linkable SPBM containing mesogenic-units is synthesized, which is pale-colored, non-photoluminescent and non-mesogenic at a spiro form, but dark-colored, photoluminescent, and mesogenic at a merocyanine form. Moreover, the dynamic interconversion behavior of the form in the different chemical environments are distinct. Liquid crystalline polymers (LCPs) containing the SPBMs cross-linked via visible light, own a photoswitchable glass transition temperature (Tg) and retain the switchable property; however, the SPBMs cross-linked via UV light will be locked at the MC state, because the molecular movement was frozen at the room temperature lower than the given Tg of the LCP. Thus, programmable chromism and photoluminescence based on the tunable Tg can be endowed to the functional materials prepared from the SPBMs.
- Hu, Wei,Qin, Shengyu,Ren, Yunxiao,Shao, Yu,Sun, Chang,Wang, Qian,Wu, Yu,Yang, Dengke,Yang, Huai,Zhang, Lanying
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supporting information
p. 19406 - 19412
(2021/08/06)
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- Synthesis, crystal structure, magnetic, spectroscopic, and theoretical investigations of two new nitronyl-nitroxide complexes
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Two mononuclear complexes [(Et3NH)[M(hfac)2L] (M = Ni, 1; Zn, 2) have been synthesized using a nitronyl-nitroxide radical substituted nitrophenol, that is 2-(2-hydroxy-3-methoxy-5-nitrophenyl)-4,4,5,5-tetramethyl-4,5-dihydro-1H-imidazol-3-oxide-1-oxyl, HL, as a proligand. The crystal structures of 1 and 2 have been solved and indicate an octahedral coordination geometry of the metal ions. The magnetic behavior for 1 is characterized by a strong antiferromagnetic metal–radical interaction (J = ?351 ± 1 cm?1; H = ?JS Ni S Rad). This exchange interaction was rationalized by DFT calculations. The EPR spectra recorded in both solution and solid state at 120 K confirm the S = ? ground state for 1.
- Spinu, Cristian Andrei,Pichon, Céline,Ionita, Gabriela,Mocanu, Teodora,Calancea, Sergiu,Raduca, Mihai,Sutter, Jean-Pascal,Hillebrand, Mihaela,Andruh, Marius
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p. 279 - 293
(2021/02/01)
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- Bioinspired Synergistic Photochromic Luminescence and Programmable Liquid Crystal Actuators
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Bioinspired smart materials with synergistic allochroic luminescence and complex deformation are expected to play an important role in many areas of science and technology. However, it is still challenging to fabricate such soft actuators with high programmability that can be manipulated in situ with high spatial resolution. Herein, we have incorporated terminally functionalized aggregation-induced emission active tetraphenylethene derivative and photochromic spiropyran moieties into the networks of liquid crystal elastomers through covalent bonding to obtain the synergistic photochromic luminescence and programmable soft actuators. Bio-mimic functions and light-induced auxetic metamaterial-like devices were shown to be feasible based on the combination of assembly and origami-programming strategy. These bioinspired devices with synergistic photochromic luminescence and complex photodeformation abilities provide an elegant strategy to design multi-functional liquid crystal actuators.
- Huang, Yinliang,Bisoyi, Hari Krishna,Huang, Shuai,Wang, Meng,Chen, Xu-Man,Liu, Zhiyang,Yang, Hong,Li, Quan
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supporting information
p. 11247 - 11251
(2021/04/16)
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- Yttrium Nitrate mediated Nitration of Phenols at room temperature in Glacial Acetic acid
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Rapid nitration of electron rich phenols using Y(NO 3) 3.6H 2O in glacial acetic acid at room temperature was observed with good yield. The method allows nitration of phenols without oxidation, and isolation of nitration product in a rapid and simple way. The described method is selective for phenols. [Figure not available: see fulltext.]
- Mondal, Mohabul A,Mandal, Debashis,Mitra, Kanchan
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- Diversely halogenated spiropyrans - Useful synthetic building blocks for a versatile class of molecular switches
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Spiropyrans are dyes that can be reversibly switched to a highly colored merocyanine form by a number of stimuli such as light, mechanical force or temperature. To make use of these molecules, there is a requirement to functionalize them appropriately. Herein we report a library of spiropyrans bearing two (pseudo) halide functional groups on either half of the molecule. Such halide substituents are valuable, because they themselves may be used as reactive sites in cross-coupling reactions, for example. Different combinations of halides, for which different reactivities in cross-coupling reactions may be expected, will facilitate selective consecutive cross-coupling reactions and condensations. Data concerning the UV/vis characteristics, the photostationary equilibria of the materials as well as the half-life of the merocyanine forms in solution are presented.
- Schulz-Senft, Mathias,Gates, Paul J.,S?nnichsen, Frank D.,Staubitz, Anne
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p. 292 - 301
(2016/09/09)
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- Synthesis and adrenolytic activity of new propanolamines
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The synthesis of (2R, S)-1-(6-methoxy-4-(methoxymethyl)-1H-indol-5-yloxy)- 3-(2-(2-methoxyphenoxy)ethylamino)propan-2-ol and (2R, S)-1-(4-methoxy-6- (methoxymethyl)-1H-indol-5-yloxy)-3-(2-(2-methoxyphenoxy)ethylamino)propan-2-ol is described. The compound
- Groszek, Grazyna,Bajek, Agata,Bis, Agnieszka,Nowak-Krol, Agnieszka,Bednarski, Marek,Siwek, Agata,Filipek, Barbara
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scheme or table
p. 3887 - 3904
(2010/10/04)
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- A new course of the Perkin cyclization of 2-(2-formyl-6-methoxyphenoxy)alkanoic acids. Synthesis of 2-alkyl-7-methoxy-5-nitrobenzo[b]furans
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2-Alkyl-7-methoxy-5-nitrobenzo[b]furan, 2-alkyl-9-methoxy-7-nitro-3-oxo-2,3-dihydro-5H-benzo[e][1,4]-dioxepin-5-yl acetate and 2-alkyl-5-hydroxy-9-methoxy-7-nitro-5H-benzo[e][1,4]-dioxepin-3-one were formed as a result of the cyclization of 2-(2-formyl-6-
- Kowalewska, Monika,Kwiecień, Halina
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p. 5085 - 5090
(2008/09/21)
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- Simple synthesis of 7-amino-4,5-dihydrobenzo[f][1,4]oxazepin-3-ones
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A simple method for the synthesis of 7-amino-4,5-dihydro-benzo[f][1,4] oxazepin-3-ones from 5-nitrobenzaldehydes and 2-haloesters was described. The three-step procedure involves the synthesis of methyl 2-(2-formyl-4- nitrophenoxy)alkanoates, followed by
- Kwiecien, Halina,Szychowska, Monika
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p. 3599 - 3609
(2008/03/13)
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- Thermo- and Photochromic Dyes: Spiro(indolinebenzopyrans) 2. - Detailed Assignment of the 1H NMR Spectra and Structural Aspects of the Closed Form of 1,3,3-Trimethylspiro(indoline-2,2'-benzopyrans)
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The proton NMR assignments for a series of 12 thermo- and photochromic 1,3,3-trimethylspiro(indoline-2,2'-benzopyrans) dyes is reported.All of the protons in the dye molecule were assigned through a combination of homonuclear decoupling experiments and correlation spectroscopy.The relative stereochemistry of the indolino gem-dimethyl groups was assigned so that, for the S-epimer, the pro-R methyl was found to resonate at 1.24 ppm while the pro-S methyl appeared at 1.37 ppm for compound 1. KEY WORDS: Thermo- and photochromic dyes, Spiro(indoline-2,2'-benzopyrans), 1H NMR assignments
- Keum, Sam-Rok,Lee, Ki-Bong,Kazmaier, Peter M.,Manderville, Richard A.,Buncel, Erwin
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p. 1128 - 1131
(2007/10/02)
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