The proton permeation process of the stator complex MotA/B in the flagellar motor of Escherichia coli was investigated. The atomic model structure of the transmembrane part of MotA/B was constructed based on the previously published disulfide cross-linking and tryptophan scanning mutations. The dynamic permeation of hydronium/sodium ions and water molecule through the channel formed in MotA/B w...

Rate constants for acid catalysis of the reactions of N-chlorodimethylamine (1), N-chloro-2,2,2-trifluoroethylamine (2) and N,N-dichlorotaurine (3) with iodide ion were determined in H(2)O at 25 degrees C and I = 0.5 (NaClO(4)). The failure to detect significant catalysis by general acids of chlorine transfer from 1 to the nucleophile, together with the observed inverse solvent deuterium isotop...

With a 3.5 m diameter telescope passively cooled to approximately 80 K, and a science payload comprising two direct detection cameras/medium resolution imaging spectrometers (PACS and SPIRE) and a very high spectral resolution heterodyne spectrometer (HIFI), the Herschel Space Observatory is providing extraordinary observational opportunities in the 55-670 μm spectral range. HIFI has opened for...

The title compound, H(3)O(+)·C(6)H(2)N(3)O(7) (-), consists of one picrate anion and one oxonium cation. The oxonium cation is located on a crystallographic twofold axis and both its H atoms are disordered, each over two symmetry-equivalent positions with occupancy ratios of 0.75. The picrate anions are also located on twofold axes bis-ecting the phenolate and p-nitro groups. π-π inter-actions ...

The title compound, (C7H10N)2(H3O)2[Fe(CN)6] or (Etpy)2(H3O)2[Fe(CN)6] (Etpy+ is 1-ethyl-pyridinium), crystallizes in the space group Pnnm. The FeII atom of the [Fe(CN)6]4- anion lies on a site with site symmetry ..2/m, and has an octa-hedral coordination sphere defined by six cyanido ligands. Both the Etpy+ and the oxonium cations are located on a mirror plane. In the crystal, electron-donor a...

A robust and accurate dissociative potential that reproduces the structural and dynamic properties of bulk and nanoconfined water, and proton transport similar to ab initio calculations in bulk water, is used for reactive molecular dynamics simulations of the proton dynamics at the silica/water interface. The simulations are used to evaluate the lifetimes of protonated sites at the interfaces o...

SnBr(4)-promoted oxonium-Prins cyclizations to form 2,3-disubstituted tetrahydrofurans (THFs) are reported. In the absence of an internal nucleophile, the carbocation intermediates are trapped by bromide to give 2,3-cis- and 2,3-trans-configured products; two variations with intramolecular trapping are also reported. One of these allows a single-step stereocontrolled synthesis of the core 2,3-c...

The title compound, (H(3)O)[Pd(C(2)H(7)NO(6)P(2))(C(2)H(8)NO(6)P(2))]·3H(2)O, was synthesized by the reaction of [Pd(H(2)O)(4)](NO(3))(2) with 1-amino-ethane-1,1-diyldiphospho-nic acid in aqueous solution. The asymmetric unit contains one mol-ecule of the complex existing as an anion, an oxonium counter-ion and three solvent water mol-ecules. The Pd(II) ion occupies a position on a pseudo-twofo...