Structural Dynamics of Chloromethanes through Computational Spectroscopy: Combining INS and DFT

In this work, the structural dynamics of the chloromethanes CCl₄, CHCl₃ and CH₂Cl₂ were evaluated through a computational spectroscopy approach by comparing experimental inelastic neutron scattering (INS) spectra with the corresponding simulated spectra obtained from periodic DFT calculations. The overall excellent agreement between experimental and calculated spectra allows a confident assignment of the vibrational features, including not only the molecular fundamental modes but also lattice and combination modes. In particular, an impressive overtone sequence for CHCl₃ is fully described by the simulated INS spectrum. In the CCl₄ spectrum, the splitting of the ν3 mode at ca. 765–790 cm⁻¹ is discussed on the basis of the Fermi resonance vs. crystal splitting controversy.     

Integrated Theoretical and Empirical Studies for Probing Substrate–Framework Interactions in Hierarchical Catalysts

Soft templating with siliceous surfactant is an established protocol for the synthesis of hierarchically porous silicoaluminophosphates (HP SAPOs) with improved mass transport properties. Motivated by the enhanced performance of HP SAPOs in the Beckmann rearrangement of cyclohexanone oxime to the nylon 6 precursor ϵ-caprolactam, an integrated theoretical and empirical study was carried out to investigate the catalytic potential of the siliceous mesopore network. Inelastic neutron scattering (INS) studies, in particular, provided unique insight into the substrate-framework interactions in HP (Si)AlPOs and allowed reactive species to be studied independent of the catalyst matrix. The spectroscopic (INS, FTIR spectroscopy, MAS NMR spectroscopy) and computational analyses revealed that in the organosilane-templated SAPO, the interconnectivity of micro- and mesopores permits cooperativity between their respective silanol and Brønsted acid sites that facilitates the protonation of cyclohexanone oxime in a physical mixture at ambient temperature.     

Quality Factor of Inhomogeneous Plane Waves

Acoustical Physics - We first compare two apparently dissimilar expressions for the quality factor Q of inhomogeneous plane waves in isotropic viscoelastic media, where Q is defined as the result...     

Inline gamma-spectrometry of fission product elements after rapid high-pressure ion chromatographic separation

Journal of Radioanalytical and Nuclear Chemistry - Analysis of irradiated material shortly after irradiation can be non-trivial due to highly radioactive activation and fission isotopes increasing...     

Solubility and Thermodynamic Properties of Dipotassium or Disodium Hydrogenphosphates in Aqueous Solutions at Various Temperatures

Journal of Solution Chemistry - In this investigation, calculated and experimental solubilities of the binary aqueous solutions of dipotassium hydrogenphosphate and disodium hydrogenphosphate have...     

An intramolecular Tsuji-Trost reaction based approach to the synthesis of 6-methylene indolizidines

Herein we describe the efficient stereoselective preparation of C8 substituted indolizidines bearing a 6-methylene group, from the chiral pool starting material l-proline. This synthesis, employing a Tsuji-Trost reaction as the key step, represents a potentially, efficient route to pumiliotoxin natural product epimers.     

Blackbody radiation functions and polylogarithms

A new method based on the polylogarithm function is used to derive an exact expression for the fractional emissive power of a blackbody in any arbitrary spectral band. Compared to all previously used methods the polylogarithm based method is unsurpassed in its simplicity. Displacement laws for the centroid of blackbody radiation in the linear wavelength and frequency spectral representations that make use of the polylogarithm based approach are also given.     

Nonmuscle Myosin II helps regulate synaptic vesicle mobility at the <Emphasis Type="Italic">Drosophila</Emphasis>neuromuscular junction

Background  

Although the mechanistic details of the vesicle transport process from the cell body to the nerve terminal are well described, the mechanisms underlying vesicle traffic within nerve terminal boutons is relatively unknown. The actin cytoskeleton has been implicated but exactly how actin or actin-binding proteins participate in vesicle movement is not clear.