The semirigid tridentate 8-(2-pyridinylmethylthio)quinoline ligand (Q1) is shown to form the structurally characterized transition metal complexes [Cu(Q1)Cl2] (1), [Co(Q1)(NO3)2] (2), [Cd(Q1)(NO3)2] (3), [Cd(Q1)I2] (4). [Cu(Q1)2](BF4)2·(H2O)2 (5), [Cu(Q1)2](ClO4)2·(CH3COCH3)2 (6), [Zn(Q1)2](ClO4)2(H2O)2 (7), [Cd2(Q1)2Br4] (8), [Ag2(Q1)2(ClO4)2] (9), and [Ag2(Q1)2(NO3)2] (10). Four types of structures have been observed: ML-type in complexes 1–4, in which the anions Cl−, NO3− or I− also participate in the coordination; ML2− type in complexes 5–7 without direct coordination of the anions BF4− or ClO4− and with more (Cu2+) or less (Zn2+) distorted bis-fac coordinated Q1; M2L2-type in complex 8, in which two Br− ions act as bridges between two metal ions; and M2(μ-L)2-type in complexes 9 and 10, in which the ligand bridges two anion binding and Ag–Ag bonded ions. Depending on electron configuration and size, different coordination patterns are observed with the bonds from the metal ions to Npyridyl longer or shorter than those to Nquinoline. Typically Q1 acts as a facially coordinating tridentate chelate ligand except for the compounds 9 and 10 with low-coordinate silver(I). Except for 6 and 8, the complexes exhibit distinct constraining effects against both G(+) and G(-) bacteria. Complexes 1, 3, 4, 5, 7 have considerable antifungal activities and complexes 1, 5, 7, and 10 show selective effects to restrain certain botanic bacteria. Electrochemical studies show quasi-reversible reduction behavior for the copper(II) complexes 1, 5 and 6. 相似文献
Electrochemical reactions in the electrochemical treatment of tumors (EChT) induce extreme pH changes and, consequently, protein electrodenaturation fronts intimately related to tumor destruction. Here we introduce a new in vitro EChT collagen–macronutrient gel (CMG) model to study protein electrodenaturation fronts as a mean of assessing EChT effectiveness. Our CMG model shows that from an initial uniform condition two electrodenaturation fronts evolve expanding towards each other until collision. Moreover, electrodenaturation front tracking reveals that the front grows under a diffusion-controlled regime. Based on this evidence it is possible, in principle, to predict the time needed for tumor destruction without compromising healthy tissue. These results are consistent with those previously obtained with in vivo and in vitro EChT modeling. In contrast to previous simpler in vitro models, our CMG model represents a better structural and chemical approximation to a real tissue thus providing a better tool for validation of new in silico EChT models aimed at a more accurate prediction of tissue destruction level. 相似文献
CdS nanocrystals (NCs) usually exhibit very weak electrochemiluminescence (ECL) emission. It is showed that when CdS NCs were treated by heating in the presence of ammonia (heated-CdS–NH3), greatly enhanced ECL was observed. The ECL of the heated-CdS–NH3 modified glassy carbon electrode (heated-CdS–NH3/GCE) in phosphate buffer solution (pH 7.0) containing 0.1 M K2S2O8 was ca. 310 times higher than that of CdS/GCE. The treatment caused the changes in the morphology and surface electronic structure of CdS NCs, which facilitated the reduction process of CdS, consequently improved the quantity of the excited states (CdS*), leading to enormous enhancement in ECL. 相似文献
Yttria-stabilized zirconia (YSZ) membranes were deposited onto porous NiO–YSZ anode supports by screen printing. Combined with La0.7Sr0.3MnO3–YSZ composite cathode, the prepared anode-supported solid oxide fuel cells (SOFCs) were electrochemically tested. A typical SOFC with a 30-μm-thick YSZ electrolyte membrane gave the maximum power densities (MPDs) of 0.26, 0.53, 0.78, and 1.03 W/cm2 at 650, 700, 800, and 850 °C, respectively, using hydrogen as fuel and stationary air as oxidant. Replacement of stationary air with pure oxygen flow exerted a significant positive effect on the MPDs of the cell. Using 100- and 200-ml/min oxygen as oxidants, the MPDs of the cell were enhanced 35.3% and 68.6%, respectively. Polarization analysis indicated that, at the MPD points, the electrode polarization resistances accounted for 80% of the cell total resistances.
A novel, highly sensitive technology for the detection, enrichment, and separation of trace amounts of target DNA was developed
on the basis of amino-modified fluorescent magnetic composite nanoparticles (AFMN). In this study, the positively charged
amino-modified composite nanoparticles conjugate with the negatively charged capture DNA through electrostatic binding. The
optimal combination of AFMN and capture DNA was measured by dynamic light scattering (DLS) and UV–vis absorption spectroscopy.
The highly sensitive detection of trace amounts of target DNA was achieved through enrichment by means of AFMN. The detection
limit for target DNA is 0.4 pM, which could be further improved by using a more powerful magnet. Because of their different
melting temperatures, single-base mismatched target DNA could be separated from perfectly complementary target DNA. In addition,
the photoluminescence (PL) signals of perfectly complementary target DNA and single-base mismatched DNA as well as the hybridization
kinetics of different concentrations of target DNA at different reaction times have also been studied. Most importantly, the
detection, enrichment, and separation ability of AFMN was further verified with milk. Simple and satisfactory results were
obtained, which show the great potential in the fields of mutation identification and clinical diagnosis. 相似文献
A novel molecular switch, 7-(N,N-diethylamino)-2-oxo-2H-chromen-4-yl ferrocene carboxylate (FCC), was synthesized and fully
characterized by 1H NMR, 13C NMR, and HRMS. Taking advantage of the properties of ferrocene as an electron donor active unit and the coumarin as a fluorescent
unit, the dyad FCC shows a fast and reversible redox-switchable fluorescence emission. In sharp contrast to most photoluminescent
chromophores, FCC has a unique enhanced emission through aggregation. The change of electrochemical signals (CV and DPV) indicated
that the ferrocene (Fc) unit of FCC could form inclusion complex with Me-β-cyclodextrin (CD). This inclusion complex could further weaken the aggregation-induced emission (AIE) effect remarkably.
This advance paves the way to introduce AIE property into molecular devices applications. 相似文献