The FTIR spectra of 4-dimethylamino pyridinium-betaine of squaric acid in 4000–100 cm frequency region in solid state were measured. In addition, the structure and harmonic vibrational frequencies of this molecule were theoretically evaluated using restricted Hartree–Fock and B3LYP density functional methods. The computed vibrational frequencies are used to determine the types of molecular moti...

A systematic vibrational spectroscopic assignment and analysis of pregabalin has been carried out by using FTIR, FT-Raman spectral data. The vibrational analysis were aided by electronic structure calculations-hybrid density functional methods (B3LYP) performed with 631G(d,p) basis set. Molecular equilibrium geometries, electronic energies, natural bond order analysis, IR intensities, and harmo...

We report experimental spectra in the mid-infrared (IR) and near-IR for a series of dibenzoacenes isolated in Ar matrices. The experiments are supported by Density Functional Theory (DFT) and Time-Dependent DFT (TD-DFT) calculations with both vibrational and electronic transitions studied. For the neutrals, we find good agreement between the experimental and B3LYP and BP86 results for all speci...

We have taken K-band spectra covering 7 cooling flow clusters. The spectra show many of the 1-0S transitions of molecular Hydrogen, as well as some of the higher vibrational transitions, and some lines of ionized Hydrogen. The line ratios allow us to conclude that the rotational states of the first excited vibrational state are in approximate LTE, so that densities above 10 cm are likely, but t...

Inelastic nuclear resonant scattering spectra of Fe atoms were measured on crystalline alloys of Pt3 Fe that were chemically disordered, partially ordered, and L12 ordered. Phonon partial density of states curves for Fe were obtained from these spectra. Upon disordering, about 10% of the spectral intensity underwent a distinct shift from 25 to 19 meV. This change in optical modes accounted for ...

Calculated structures of the two most stable conformers of a protonated decapeptide gramicidin S in the gas phase have been validated by comparing the vibrational spectra, calculated from first- principles and measured in a wide spectral range using infrared (IR)-UV double resonance cold ion spectroscopy. All the 522 vibrational modes of each conformer were calculated quantum mechanically and c...

We propose the possibility of using vibrational population transfer to enhance the structural markers for protein motifs that occur in two-dimensional infrared spectroscopy. We demonstrate the potential of this method by calculating the spectrum of the trpzip2 beta-hairpin peptide, a system that is small enough to allow accurate simulation of its two-dimensional infrared spectra, including vibr...

The gallium(III) complex of orotic acid (HOA) was synthesized and its structure was determined by means of analytical and spectral analyses. Detailed vibrational analysis of HOA, sodium salt of HOA (NaOA) and Ga(III)-OA systems based on both the calculated and experimental spectra confi rmed the suggested metal-ligand binding mode. Signifi cant differences in the IR and Raman spectra of the com...

We have obtained spectra of the high-lying vibrational levels of the ASu 1 and 1Sg states of both Li2 and Li2 via photoassociation of colliding ultracold atoms confined to a magneto-optical trap. Because of the low collision energies (;1 mK!, very high spectroscopic resolution is realized, and sensitivity is greatest for the usually difficult to access long-range states. Binding energies relati...

The vibrational motion of a molecule is quantized and the resulting energy level spacings give rise to transitions in the mid-IR portion of the electromagnetic spectrum (4000 to ca. 400 cm). As you know from study of the diatomic harmonic oscillator, the energies (or wavenumber positions, cm) of these transitions are related to the bond strength (force constant), bond length, and atomic masses ...