We demonstrate a technique for IR action spectroscopy that enables measuring IR spectra in a background-free fashion for low-temperature neutral gas-phase molecules of arbitrary structure. The method is exemplified experimentally for N-methylacetamide molecules in the mid-IR spectral range of 1000-1800  cm^{-1}, utilizing the free electron laser FELIX. The technique involves the resonant absorp...

Identification of clay minerals based on chemometric analysis of measured infrared (IR) spectra was suggested. IR spectra were collected using the diffuse reflection technique. Discriminant analysis and principal component analysis were used as chemometric methods. Four statistical models were created for separation and identification of clay minerals. More than 50 samples of various clay miner...

The spectra of osmium and iridium were photographed in the 300 Å to 1600 Å region on a 3 m normal incidence spectrograph using a triggered spark source. The (5d2 + 5d6s)-5d6p transition arrays of Os VII and Ir VIII were analyzed. All levels of these three configurations in both spectra have been established. There are 77 lines in Os VII and 71 lines in Ir VIII classified. The parametric least s...

Niobium and tantalum carbide clusters have been isolated in the gas phase and irradiated with intense tunable infrared (IR) light. Stable neutral clusters are selectively ionized and subsequently detected in a mass spectrometer. By tuning the IR frequency, infrared multiphoton absorption spectra are obtained for a whole range of clusters. These mass-selective IR spectra lead to insights into th...

We report the infrared (IR) absorption spectra of different conformational isomers of gas phase amino acid molecules in the molecular fingerprint region of 330-1500 cm(-1). The IR absorption spectra for three conformers of the amino acid tryptophan show absorption bands that uniquely identify the conformational structure of the molecule and that are well matched by density functional theory cal...

The assignment of the vibrational modes in amorphous carbon nitride (CN) films is discussed by considering CN films deposited using a variety of methods. The infrared (IR) spectra of CN show three main absorption bands. In hydrogenated CN samples, CH and NH groups give rise to stretching vibrations at 3000 and 3400 cm , respectively. A weaker sharp band is y1 x x observed approximately 2200 cm ...

An ab initio study has been performed for the electronic, spectroscopic, and chemical properties of the most stable configuration of the (CdO)n nanoclusters by employing B3LYP-DFT/LanL2DZ method. Different isomers were optimized to obtain structural stability and numerous chemical parameters such as dipole moment, ionization potential, etc. We report here the vibrational frequencies of the most...

Rapid identification of microbial pathogens reduces infection-related morbidity and mortality of hospitalized patients. Raman spectra and Fourier transform infrared (IR) spectra constitute highly specific spectroscopic fingerprints of microorganisms by which they can be identified. Little biomass is required, so that spectra of microcolonies can be obtained. A prospective clinical study was car...

FT-IR and FT-Raman spectra of hirudin have been recorded from the native solid hirudin. The conformation of the molecule has been discussed on the basis of IR and Raman data. It has been concluded that hirudin molecule has a mixed a-helix and random coil conformation.