Simple halogen substituents frequently afford key structural features that account for the potency and selectivity of natural products, including antibiotics and hormones. For example, when a single chlorine atom on the antibiotic vancomycin is replaced by hydrogen, the resulting antibacterial activity decreases by up to 70% ( Harris , C. M. ; Kannan , R. ; Kopecka , H. ; Harris , T. M. J. Am. ...

The use of the halide-sensitive fluorescent probes (6-methoxy-N-(-sulphopropyl)quinolinium (SPQ) and N-(ethoxycarbonylmethyl)-6-methoxyquinolinium bromide (MQAE)) to measure chloride transport in cells has now been established as an alternative to the halide-selective electrode technique, radioisotope efflux assays and patch-clamp electrophysiology. We report here procedures for the assessment ...

Time-resolved extinction spectroscopy is employed to study the reaction kinetics in the shape-conversion reaction involving halide ions (including Cl(-), Br(-) and I(-)) etching (sculpturing) silver nanoplates. A series of time-resolved extinction spectra are obtained during the in situ etching process and the evolution of surface plasmon resonance (SPR) of the silver nanoparticles is analyzed....

We report a facile halide ion (Cl(-) or Br(-)) mediated synthesis of Fe nanoparticles (NPs) by thermal decomposition of Fe(CO)5. The NP structure is controlled to be either amorphous (in the absence of halide ions) or single crystalline bcc (in the presence of halide ions). Through systematic investigation on the synthetic conditions, we have confirmed that the formation of bcc-Fe NPs is facili...

Accurate prediction of melting points of ILs is important both from the fundamental point of view and from the practical perspective for screening ILs with low melting points and broadening their utilization in a wider temperature range. In this work, we present an ab initio approach to calculate melting points of ILs with known crystal structures and illustrate its application for a series of ...

the effects of substituents on the symmetry and the nature of halogen bonds in [n∙∙∙x∙∙∙n]+-type systems are presented for the yc5h4n∙∙∙x∙∙∙nc5h5 (y = no2, cn, h, ch3, och3, oh, nh2, x = cl, br, i) complexes. some structural parameters, energy data and electronic properties were explored with the density functional theory (dft) calculations. in addition, electrostatic potentials were used in es...

A series of acyclic anion receptors containing chalcogen bond (ChB) and halogen (XB) donors integrated into a neutral 3,5-bis-triazole pyridine scaffold are described, in which systematic variation the electronic-withdrawing nature aryl substituents reveal dramatic modulation sigma-hole donor atom potency for recognition. Incorporation strongly electron-withdrawing perfluorophenyl units appende...

für Naturforschung in cooperation with the Max Planck Society for the Advancement of Science under a Creative Commons Attribution 4.0 International License. Dieses Werk wurde im Jahr 2013 vom Verlag Zeitschrift für Naturforschung in Zusammenarbeit mit der Max-Planck-Gesellschaft zur Förderung der Wissenschaften e.V. digitalisiert und unter folgender Lizenz veröffentlicht: Creative Commons Namen...

Halohydrin dehalogenase (HheC) from Agrobacterium radiobacter AD1 catalyzes the dehalogenation of vicinal haloalcohols by an intramolecular substitution reaction, resulting in the formation of the corresponding epoxide, a halide ion, and a proton. Halide release is rate-limiting during the catalytic cycle of the conversion of (R)-p-nitro-2-bromo-1-phenylethanol by the enzyme. The recent elucida...