Far-infrared vibrational modes of polycrystalline saccharides

Far-infrared vibrational modes of polycrystalline saccharides

We have measured the temperature dependence of the far-infrared vibrational modes of polycrystalline saccharide molecules in the frequency range 0.1–3.0 THz using a time-resolved terahertz spectroscopy system. Coherent measurement of the transmitted terahertz electric fields showed distinct absorption features, in both monosaccharides and disaccharides, originating from interand intra-molecular...

Optical properties of polycrystalline diamond films in the far-infrared

Room temperature Fourier transform spectroscopic transmissivity data in the far-infrared (10 360 cm-1) were used to derive a model for the complex refractive index (n ik) of polycrystalline diamond films grown by microwave plasma enhanced chemical vapor deposition. Transmission measurements were also made at a frequency of 19.5 cm-1 utilizing a CO2 optically pumped submillimeter laser. Due to t...

Properties of local vibrational modes: the infrared intensity

For the local (adiabatic) vibrational modes of Konkoli and Cremer (Int J Quantum Chem 67:29–40, 1998), infrared intensities are derived by setting up the appropriate adiabatic conditions. It is shown that the local mode intensities are independent of the coordinates used to describe a molecule and correctly reflect the molecular symmetry and isotope composition. Normal mode intensities are rela...

Soft Modes in the Far — Infrared Spectrum Of

Excited-state lifetimes of far-infrared collective modes in proteins.

Vibrational excitations of low frequency collective modes are essential for functionally important conformational transitions in proteins. Here we report the first direct measurement on the lifetime of vibrational excitations of the collective modes at 87 pm (115 cm(-1)) in bacteriorhodopsin, a transmembrane protein. The data show that these modes have extremely long lifetime of vibrational exc...