Infrared spectroscopy (IR) is a staple structural elucidation and characterization technique because of its ability to identify functional groups ease use. Interestingly, it allows the capture electronic effects via their influence on bond strength “probes”, such as carbonyl group also offers wealth examples for discussion theory transitions. For this reason, IR typically taught both in theoret...

In order to estimate the influence of both surface and interface effects on phonon frequencies and superconducting transition temperatures in layered structures, we have calculated the vibrational modes of structures composed of alternating films of heavy and light particles. An interface effectively lowers the vibrational frequencies of the heavy particles and raises those of the light particl...

Thermodynamic properties of selected small and medium size molecules were calculated using harmonic and anharmonic vibrational frequencies. Harmonic vibrational frequencies were obtained by normal mode analysis, whereas anharmonic ones were calculated using the vibrational self-consistent field (VSCF) method. The calculated and available experimental thermodynamic data for zero point energy, en...

For the first time investigation of water molecule complexed with methylamine (CH3NH2) in solid neon was performed from 80 to 6000 cm−1 using Fourier transform infrared spectroscopy. From concentration effects and help theoretical results we have identify several vibrational transitions for CH3NH2 dimer, CH3NH2-H2O, CH3NH2-(H2O)2 complexes. CH3NH2-H2O complex, where two submolecules interacting...

Submitted for the MAR13 Meeting of The American Physical Society Computational NMR, IR/RAMAN calculations in sodium pravastatin: Investigation of the Self-Assembled Nanostructure of Pravastatin-LDH (Layered Double Hydroxides) Systems1 PHILIPPE PETERSEN, VANESSA CUNHA, MARCOS GONÇALVES, HELENA PETRILLI, VERA CONSTANTINO, Universidade de Sao Paulo, INSTITUTO DE F́ıSICA, DEPARTAMENTODE F́ıSICA DEMAT...

The difference spectroscopy of the Raman optical activity (ROA) provides extended information about molecular structure. However, interpretation of the spectra is based on complex and often inaccurate simulations. Previously, the authors attempted to make the calculations more robust by including the solvent and exploring the role of molecular flexibility for alanine and proline zwitterions. In...

Water hydrogen bond dynamics in concentrated salt solutions are studied using polarization-selective IR pump-probe spectroscopy and 2D IR vibrational echo spectroscopy performed on the OD hydroxyl stretching mode of dilute HOD in H(2)O/salt solutions. The OD stretch is studied to eliminate vibrational excitation transfer, which interferes with the dynamical measurements. Though previous researc...

Combined density functional and multireference configuration interaction methods have been employed to explore the ground and low-lying electronically excited states of the most important tautomeric and rotameric forms of guanine with the purpose of resolving the conflicting assignments of IR-UV bands found in the literature. The calculations predict sharp 1(pi-->pi*) origin transitions for the...

In the presence of lipid bilayers, the hexapeptide AcWL(5) forms membrane-bound aggregates dominated by beta-secondary structure and is thus a useful model for the onset of peptide aggregation in membrane environments. Two-dimensional infrared (2D IR) spectra in the amide I region for aggregates of AcWL(5) peptides with single isotopic labels provide new insight into the residue-level structura...

There is a need to develop mid-infrared (IR) spectrometers for applications in which the absorbance of only a few vibrational mode (optical) frequencies needs to be recorded; unfortunately, there are limited alternatives for the same. The key requirement is the development of a means to discretely access a small set of spectral positions from the wideband thermal sources commonly used for spect...