The aminosilane-modified magnetite nanoparticles were synthesized by the coprecipitation and surface modification with 3-aminopropyltriethoxysilane (APTTS). The superparamagnetic APTTS/Fe3O4 nanospheres with an average diameter of 10 nm were characterized significantly with functional group, well dispersion and stabilization in aqueous fluids, as well as a maximized saturation magnetization of 63.54 emu/g.
Bimetallic CuNi nanoparticles (NPs) with low cost were rationally confined inside MIL-101 to give CuNi@MIL-101, which exhibits high efficiency and excellent recyclability toward the hydrogenation of nitroarenes under mild conditions on coupling with ammonia borane dehydrogenation. This is the first report on MOF-stabilized base metal NPs for cascade reactions.
An imidazolate-bridged homodinuclear complex, {[Cu(L)(H2O)]2(im)}(ClO4)3 (1), assembled with beta-cyclodextrin (betaCD) and its guanidinium-containing derivative (betaGCD), and thus a helical inclusion complex, {[Cu(L)(H2O)(betaCD)]2(im)}(ClO4)3 (2), were successfully isolated and structurally characterized. Structural analysis showed that each Cu(II) ion has a distorted square pyramidal N4Ow coordination sphere and forms a chiral chain through hydrogen-bonding and hydrophobic interactions. The UV-vis data showed that such a chain can provide the imidazolate bridge additional stability and results in the dissociation equilibrium taking place at the physiological pH. The obtained IC50 value for 2 (0.23 muM) showed a high superoxide dismutase (SOD) activity, which corresponds to a highly stable imidazolate bridge. Interestingly, the guanidinium-containing 1/betaGCD system showed higher SOD activity (IC50 = 0.16 muM), which is enhanced at least by 30% in comparison with that of guanidinium-lacking 2. This result supports that the positive guanidinium plays a role in the catalytic mechanism of Cu,Zn-SOD by ensuring that superoxide enters and peroxide leaves rapidly from the coordination sphere of the copper ion.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.