Hans H. Eysel

Schwingungsspektroskopische untersuchung von hexamminkobalt(III)- und -chrom(III)-salzen

Zusammenfassung Raman- and Ultrarotspektren der Komplexe [Co(NH3)6]3+, [Co(ND3)6]3+ und [Cr(NH3)6]3+ mit verschiedenen Anionen werden angegeben. Die Zuordnung und der Einfluss der Kristallgittersymmetrie auf die Spektren werden diskutiert.

Carbon Dioxide Clathrates: An IR Spectroscopic Marker for Arthritis?

The IR spectra of dry films of synovial fluid from normal and arthritic joints are presented. The spectra suggest the existence of CO2 clathrates in these fluids which are of remarkable stability in comparison to well-known CO2 clathrate hydrates. To our knowledge, this is the first demonstration of the formation of CO2 clathrates in biological media. The proportion of CO2 clathrates found in synovial fluid appears to vary with the state of health of joints and thus may be of use in the clinical diagnosis of arthritis.

Schwingungsspektren, kraftkonstanten und struktur der halogen-substituierten sulfinylamine

Zusammenfassung Ultrarot- und Raman-Spektren der Reihe XNSO mit X = F, Cl, Br, J, wurden aufgenommen. Die Verbindungen sind eben gebaut, Symmetrie CS. Aus den P-R-Abstanden der Gasspektren ergibt sich die cis-Konfiguration. Die Kraftkonstanten der Verbindungen wurden fur ein allgemeines Valenzkraftfeld berechnet, einschliesslich des HNSO und DNSO. Die Valenzkraftkonstanten stimmen fur cis-Struktur mit den Werten uberein, die nach den Elektronegativitaten der X-Atome zu erwarten sind.

Corrections to the Baseline Distortions in the OH-Stretch Region of Aqueous Solutions

The intensity gains or intensity losses of the OH-stretch vibrations and their changes of band shapes as observed in IR or Raman spectra of dilute aqueous solutions of carboxylic acids, amino acids, and amines were able to be simulated. The difference spectra of the type {sample solution} – {standard} x {empirical factor} displayed essentially flat baselines throughout the OH-stretch region of isotropic Raman scattering. Peaks of the solute spectra which had been hidden by the OH-stretch contour emerged from the background. At concentrations below 1 M, pure water was the standard. Distortions of the isotropic Raman spectra at higher solute concentrations (1 M to 4 M) could be mimicked by phosphoric acid or sulfuric acid solutions as standards. The influence of solutes on the reorientational motions of water molecules made baseline corrections of anisotropic Raman scattering and IR absorption of the more concentrated solutions difficult, if not impossible.

Raman and FTIR spectroscopic study on water structural changes in aqueous solutions of amino acids and related compounds

Abstract Structural changes of water in aqueous solutions of glycine, alanine, ammonia, amines (methyl-, ethyl-, propyl-, and n-butylamine), carboxylic acids (formic, acetic, propionic, and n-butyric acid), KF and 1-hexansulphonic acid sodium salt have been analysed using FTIR and Raman difference spectroscopy. Isotropic and anisotropic Raman spectra, as well as the rhospectra, have been calculated. The OH stretching region of the amino acid difference spectra shows changes in defined frequency regions which can be attributed to electrostatic and hydrophobic interactions as well as to hydrogen bonding. Point charges affect the symmetry of the water molecules, while for hydrophobic interaction no symmetry changes in the water molecules are observed.

Dynamic sulfate disorder in potassium alum. A single crystal raman study

Single crystal Raman spectra of the ν1 sulfate vibration of potassium aluminium alum are discussed in terms of a disordered structure. The temperature dependence of intensities suggests occupation of two surfate sites which differ by 2009 J mol−1 in energy.

Polarized raman spectra and intensities of aromatic amino acids phenylalanine, tyrosine and tryptophan

Abstract The prominent marker bands in the Raman spectra of the aromatic proteinogenic amino acids phenylalanine, tryptophan and tyrosine have been reinvestigated. Previous studies have been extended by measuring intensities against NaClO 4 as an external standard. Raman spectra were divided into isotropic (trace scattering of symmetric vibrations) and anisotropic (quadrupole scattering of antisymmetric or symmetric vibrations). These intensity and polarization properties of the marker bands were followed through pH changes from about 11–13 to 1–2.

Schwingungsspektrum und kraftkonstanten von tetramethyltitan

Abstract The Raman and infrared spectra of Ti(CH 3 ) 4 dissolved in diethylether are presented. Force constant calculations and comparison with the force constants of other tetramethyl compounds show that Ti(CH 3 ) 4 has tetrahedral symmetry ( T d point group). The stretching force constant of the Ti-C bond has a value of 2.28 mdyn/A. It is about 20 % lower than would be expected for a group IV B element of the same mass or of the same nucleus charge.

Raman intensities of liquids: Absolute scattering activities and electro-optical parameters of the halate ions ClO3−, BrO3−, and IO3− in aqueous solutions

Abstract Absolute Raman scattering activities of aqueous solutions of sodium bromate and lithium iodate have been measured against NaClO 4 as an external standard. Electro-optical parameters (EOPs) for the BrO and IO bonds were calculated. Equilibrium bond polarizabilities were estimated from refractive index measurements in connection with Raman intensities of the bending modes. Relations between Bragg—Slater radii and EOPs are discussed. EOPS calculated from experimental data are compared with those from ab initio calculations.

Vibrational spectra of S7Se and a common force field for 34S8, 32S8 and S7Se

Abstract Raman spectra of solid S 7 Se have been recorded both at room temperature and at low temperatures down to ~30 K. Abnormal half-widths of the low-temperature spectra compared with those of S 8 indicate that an ordered phase of S 7 Se does not exist. Simultaneous calculations of a valence force field for 32 S 8 , 34 S 8 and S 7 Se yielded a refined force field for elemental sulphur along with the force constants of SSe bonds and SSeS angle deformations. The observed frequencies are reproduced to within 0.5% for all three molecules.