RESUMEN
Disclosed herein is a cross-dehydrogenative-coupling reaction of N-heterocycles including 1,2,4-triazine-3,5(2H, 4H)-diones and quinoxaline-2(1H)-ones with N-methylanilines to form C(sp2)-C(sp3) under visible-light illumination and ambient air at room temperature. In this process, easily available Ru(bpy)3Cl2·6H2O serves as the catalyst, and air acts as the green oxidant. This method features high atom economy, environmental friendliness, and convenient operation and provides an efficient and practical access to aminomethyl-substituted N-heterocycles with extensive functional group compatibility in 40-86% yields.
RESUMEN
The unit-cell parameters for the title mixed-metal coordination polymer, {[NiSr(C(3)H(2)O(4))(2)(H(2)O)(5)]·2H(2)O}(n), which is isostructural with its Co-containing analogue, were reported previously [Gil de Muro et al. (1999 â¶). Eur. J. Inorg. Chem. pp. 935-943]; the full crystal structure including a description of the hydrogen bonding is reported here. The Sr(2+) ion is bonded to five O atoms from three different malonate dianions and four water mol-ecules, displaying a distorted tricapped trigonal-prismatic coordination geometry. Two malonate dianions, two water mol-ecules and one Ni(2+) ion build up a dianionic [Ni(C(3)H(2)O(4))(2)(H(2)O)(2)](2-) unit incorporating a slightly distorted NiO(6) octa-hedron, which coordinates to three nearby Sr(2+) ions. This arrangement creates a metal-organic framework having a 20-membered ring with four Ni and six Sr atoms lying in the bc plane. The coordinated and uncoordinated water mol-ecules are responsible for the formation of two D5 hydrogen-bonded water chains within the 20-membered ring and they are linked into an R4 water cluster via two bifurcated O-Hâ¯(O,O) links.
RESUMEN
The immobilization of aptamer and the introduction of signal molecule are two keys for the development of electrochemiluminescence (ECL) aptasensor. Herein, the immobilization strategy with graphene oxide (GO) and a functional oligonucleotide (FO) are used to develop a sensitive aptasensor with the detection of thrombin as a model. After GO is attached on glass carbon or gold electrodes through physical adsorption, the amino-tagged aptamer is immobilized on the electrode surface via an amide linkage between the amino group at the end of aptamer and the carboxyl groups on GO. The FO is designed to contain two parts: the complementary strand and an intermolecular duplex for the intercalation of Ru(phen)3²âº as ECL probe. The hybridization between aptamer and its complementary part at FO achieves the introduction of Ru(phen)3²âº probe onto the electrode surface for high ECL emission. The hybrid between aptamer and thrombin leads to the release of FO containing the intercalated Ru(phen)3²âº probe. Correspondingly, the decreased ECL emission is used to quantify thrombin. The concentration-dependent response of thrombin is observed between 0.90 pM and 226 pM with a detection limit of 0.40 pM. While GO is used to immobilize the aptamer with various electrodes, such as glass carbon electrode and gold electrode in this work, GO can also preconcentrate TPrA on its surface to improve the sensitivity. The well-designed label-free ECL aptasensor strategy can be easily extended to other targets via the selection of their aptamers.