In an effort to elucidate their structures, mass-selected Cl--(CH4)n (n = 1-10) clusters are probed using infrared spectroscopy in the CH stretch region (2800-3100 cm(-1)). Accompanying ab initio calculations at the MP2/6-311++G(2df,2p) level for the n = 1-3 clusters suggest that methane molecules prefer to attach to the chloride anion by single linear H-bonds and sit adjacent to one another. These conclusions are supported by the agreement between experimental and calculated vibrational band frequencies and intensities. Infrared spectra in the CH stretch region for Cl--(CH4)n clusters containing up to ten CH4 ligands are remarkably simple, each being dominated by a single narrow peak associated with stretching motion of hydrogen-bonded CH groups. The observations are consistent with cluster structures in which at least ten equivalent methane molecules can be accommodated in the first solvation shell about a chloride anion.
Anharmonic computations reveal an intense, narrow (20 cm, 0.043 μm) absorption feature at approximately 2160 cm (4.63 μm) in the vibrational spectra of 14 prototypical singly isocyano-substituted polycyclic aromatic hydrocarbons (NC-PAHs) attributed to the NC stretching mode.
Laboratório de Espectroscopia Molecular, Departamento de Química Fundamental, Instituto de Química, Universidade de São Paulo, 05513-970 São Paulo, SP, Brazil.
Molecular dynamics (MD) simulation is used to study the intermolecular dynamics in the THz frequency range of the ionic liquid 1-ethyl-3-methylimidazolium bis(fluorosulfonyl)imide, [C2C1im][FSI]. Non-polarizable and polarizable models for classical MD simulation are compared using as quality criteria ab initio molecular dynamics (AIMD) and experimental data from far-infrared (FIR) spectroscopy and previously published data of inelastic x-ray scattering (IXS). According to data from IXS spectroscopy, incorporating polarization in the classical MD simulation has relatively little effect on the dispersion curve (excitation frequency vs wavevector) for longitudinal acoustic modes.
Department of Agrobiotechnology, IFA-Tulln, Institute of Bioanalytics and Agro-Metabolomics, BOKU University, Konrad-Lorenz-Str. 20, 3430 Tulln an der Donau, Austria.
Assessing the quality of wheat, one of humanity's most important crops, in a straightforward manner, is essential. In this study, analysis of variance (ANOVA) simultaneous component analysis (ASCA) paired with near-infrared spectroscopy (NIRS) was used as an easy-to-implement and environmentally friendly tool for this purpose. The capabilities of combining NIRS with ASCA were demonstrated by studying the effects of sampling site and year on the quality of 180 Austrian wheat samples across four sites over 3 years.
Aromatic organometallic complexes, such as ferrocene and the "inverse sandwich complex" [NaCp], are stabilized via charge-transfer (C-T) interactions and cation-π interactions (i.e., charge-induced dipole and charge-quadrupole interactions).
NMPA Key Laboratory for Technology Research and Evaluation of Drug Products, School of Pharmaceutical Sciences, Cheeloo College of Medicine, Shandong University, Jinan, Shandong, 250012, China; Shandong Engineering Research Center for Transdermal Drug Delivery Systems, Jinan, Shandong, 250000, China; National Glycoengineering Research Center, Shandong University, Jinan, Shandong, 250012, China. Electronic address:
Esophageal cancer (EC), the fifth most common cause of cancer-related mortality in China, poses a significant threat to public health. Among the pathological types, esophageal squamous cell carcinoma (ESCC) is predominant, comprising approximately 90 % of cases. Screening is crucial for early detection, diagnosis and treatment, thereby reducing ESCC mortality.
