158034-75-4

Upstream product

• 920-46-7 Methacryloyl chloride 
• 23001-29-8 6-hydroxy spiropyran 

Relevant academic research and scientific papers

Photo-reversible and selective Cu2+ complexation of a spiropyran-carrying sulfobetaine copolymer in saline solution

A sulfobetaine copolymer (1) carrying a photochromic spiropyran residue was synthesized, which reversibly isomerized between the closed and open forms in pure water and in saline by irradiation with visible light. The thermodynamic stability of the open form of the spiropyran methacrylate (SPMA) units of compound 1 was reduced upon increasing NaCl concentration. In addition, photo-reversible and selective Cu2+ complexation in saline solution ([NaCl] = 1.0 wt%) was achieved using compound 1 with metal ions (Cu 2+, Zn2+, Ni2+, or Co2+). Covalently cross-linked compound 1 showed selective Cu2+ adsorption in pure water. In contrast, the other metal ions were increasingly adsorbed as NaCl concentration increased, resulting in lower selectivity of Cu2+ ion adsorption with 1, e.g., the ratios of adsorption of Cu2+, Zn 2+, Ni2+, and Co2+ with 1 in 10 wt% saline were 73, 20, 10, and 3%, respectively, while only Cu2+ adsorption was observed in a solution of 1.0 wt% NaCl. Because the stability of the open form of the SPMA units and the metal complexation of 1 were influenced by NaCl concentration, the electrostatically cross-linked networks of the zwitterionic sulfobetaine units of 1 may be loosened by NaCl addition, resulting in easy entry of metal ions into the network. The order of metal complexation among the four metals corresponded to the Irving-Williams series. Hydrogen-bonded networks of water molecules also may contribute to the relatively ineffective selective adsorption of Cu2+ ions by 1 compared to the electrically neutral spiropyran-carrying copolymer of N-isopropylacrylamide, 2.

Multiresponsive spiropyran-based copolymers synthesized by atom transfer radical polymerization

Multiresponsive spiropyran-based random copolymers were synthesized by atom transfer radical polymerization. The polymers were prepared by the copolymerization of 2-(dimethylamino)ethyl methacrylate (DMAEMA) with the photochromic monomer 1′,3′,3′-trimethyl-6- methacryloyloxyspiro(2H-1-benzopyran-2,2′-indoline) (SP). The solvatochromic, pH, temperature, and light responsive behavior of the PDMAEMA-co-PSP polymers in solution was monitored by UV/vis spectroscopy. The copolymers exhibited reverse photochromism and stabilized the planar zwitterionic form of the chromophore, leading to negative solvatochromism upon increasing the polarity of the solvent, in contrast to a poly(methyl methacrylate)-co-PSP analogue which stabilized a nonpolar photoisomer and exhibited negligible sensitivity to the polarity of the surrounding medium, before irradiation. Moreover, the PDMAEMA-co-PSP copolymers exhibited a reversible pH-responsive character in aqueous media; the addition of a strong acid induced the SP-to-merocyanine (MC) isomerization, the formation of [MC-OH]+ and [SP-NH]+ species, and the disappearance of the H-type aggregates, whereas the initial SP moieties were recovered in alkaline media. The chromophore content and the photoinduced MC-to-SP isomerization affected the transition temperature of the PDMAEMA-co-PSP polymers. The lower critical solution temperature (LCST) of the copolymers increased with their content in hydrophilic MC moieties, while the MC-to-SP photoinduced isomerization decreased significantly the LCST due to the hydrophobic character of the SP units. Finally, the copolymers exhibited a first-order photoinduced bleaching of the chromophore units in water and acetonitrile, with a slower decoloration rate in the aqueous medium due to the effective stabilization of the bipolar MC form in the polar environment.

Photo-reversible Pb2+-complexation of insoluble poly(spiropyran methacrylate-co-perfluorohydroxy methacrylate) in polar solvents

The first demonstration of photo-reversible Pb2+-complexation of an insoluble spiropyran-carrying copolymer in aqueous solutions is presented.