In the current review of the journal Structural Chemistry, the contents of the issues 1–3 for the calendar year 2012 are related to thermochemistry. A brief thermochemical commentary is added to the summary of each article. 相似文献
Biphenyl derivative N-allyl-N′-(4′-nitro[1,1′-biphenyl]-4-yl)thiourea (BP1) was synthesized as a functional fluorescent sensor for protons and their photophysical properties were studied. The influence of environment protonation on photophysical properties of the biphenyls in solutions was investigated using UV absorption, steady-state and time-resolved fluorescence spectroscopy. Semi-empirical and DFT calculations and optimization of the molecular structure of the biphenyl derivatives in vacuum, in polar solvents and in a proton-rich environment were conducted using the HyperChem, Amsol and Gaussian3 software package. Fluorescence quenching with addition of acidic acid was observed and the Stern-Volmer quenching rate constant was about 3.0×109 M−1 s−1. Intermolecular hydrogen bonds formations by the protons with the sulphur being substituted to the biphenyls generate charge movement and strong increase (×5) of the dipole moment of the fluorophore. 相似文献
Polyamidoamine (PAMAM) dendrimers impact on activity of acetylcholinesterase was studied. It has been shown that dendrimers induce a biphasic effect: depending on their concentrations they increase or decrease enzyme activity. It may be due to two types of interactions: direct--between dendrimers and the enzyme; indirect--via a modification of the physical state of membrane phospholipids affecting the acetylcholinesterase. 相似文献
The electrochemical oxidation of coumaric acid, a biorefractory compound present in several industrial waste waters, has been investigated by use of Pt-Ti anodes and at electrolyte concentration (0.02 N NaCl or Na2SO4) low enough to allow direct dischargeability of the waste water into superficial water basins according to the Italian law (DL 152/11-5-99). Particularly, the role of the electrolyte over the conversion rate has been assessed. The obtained results show that the oxidation process should take place both at the electrode surface and in the bulk of the solution, via electrochemically-generated oxidising species (H2O2, persulfates, Cl2, NaClO). The faster coumaric acid abatement rates were found with chloride based electrolytes, which, however, lead to the formation of non-biodegradable small-molecular-weight chlorinated hydrocarbons. 相似文献
The crystal and molecular structure of the title compound, (C4H12N)2[Mo6O19]·H2O, has been determined from X‐ray diffraction data. The polyoxoanion [Mo6O19]2? is built up from six distorted MoO6 octahedra sharing common edges and one common vertex at the central O atom, and has crystallographic m3m (Oh) symmetry. The cation has crystallographic 3m symmetry. 相似文献
Liquid chromatography with diode-array detection has been used for simultaneous analysis of eight water-soluble synthetic colorants (E102, E104, E110, E122, E124, E129, E131, and E133) in non-alcoholic beverages. The colors were separated in 15 min on a C18 reversed-phase column with a linear mobile phase gradient prepared from tetrabutylammonium hydrogen sulfate, methanol, and deionized water. The analytical characteristics of the separation were evaluated. Good linearity (r2 = 0.9988–0.9999), adequate limits of quantification, and high recovery (from 96.3 to 98.5%) were achieved. The method was used for analysis of 57 samples of soft drinks. The experimental results showed the colorants were present in 34 of the samples, and confirmed the method is sensitive, rapid, precise, and suitable for routine analysis of synthetic organic dyes.
Nanostructured bioelectrodes were designed and assembled into a biofuel cell with no separating membrane. The glassy carbon
electrodes were modified with mediator-functionalized carbon nanotubes. Ferrocene (Fc) and 2,2′-azino-bis (3-ethylbenzothiazoline-6-sulfonate)
diammonium salt (ABTS) bound chemically to the carbon nanotubes were found useful as mediators of the enzyme catalyzed electrode
processes. Glucose oxidase from Aspergillus niger AM-11 and laccase from Cerrena unicolor C-139 were incorporated in a liquid-crystalline matrix-monoolein cubic phase. The carbon nanotubes–nanostructured electrode
surface was covered with the cubic phase film containing the enzyme and acted as the catalytic surface for the oxidation of
glucose and reduction of oxygen. Thanks to the mediating role of derivatized nanotubes the catalysis was almost ten times
more efficient than on the GCE electrodes: catalytic current of glucose oxidation was 1 mA cm−2 and oxygen reduction current exceeded 0.6 mA cm−2. The open circuit voltage of the biofuel cell was 0.43 V. Application of carbon nanotubes increased the maximum power output
of the constructed biofuel cell to 100 μW cm−2 without stirring of the solution which was ca. 100 times more efficient than using the same bioelectrodes without nanotubes
on the electrode surface. 相似文献