Fourier transform spectroscopy

About: Fourier transform spectroscopy is a research topic. Over the lifetime, 5418 publications have been published within this topic receiving 134133 citations.

Fourier Transform Infrared Spectroscopy Investigations of Protein Structure

Abstract: It has been recognized since 1950 (Elliott and Ambrose, 1950) that infrared spectroscopy has the potential to provide information regarding protein secondary structure. Krimm lists nine protein-sensitive infrared active vibrations arising from the amide backbone linkage (Krimm and Bandekar, 1986). The majority of protein structural information, however, has been obtained from one absorbance originating primarily from the amide C=O stretching vibrations: the amide I band. The sensitivity to variations in both geometric arrangement of atoms and hydrogen bonding enables infrared spectroscopy to discriminate between the various secondary structures, i. e., helical, extended sheet, unordered, and turns, incorporated within the three-dimensional organization of peptides and proteins. Many studies have demonstrated, both theoretically and experimentally, that infrared spectroscopy can be used to identify specific secondary structures.

High‐Resolution Fourier Transform Infrared Spectroscopy

Abstract: Recent developments and applications of high-resolution Fourier transform spectroscopy are reviewed. A short historical summary of the development of high-resolution interferometric Fourier transform infrared (FTIR) spectrometers is given and the possibilities of the currently most highly resolving FTIR spectrometers, including a current prototype built for the Zurich group at the Swiss Light Source SLS as a synchrotron light source, are discussed. A short description of the principles of FTIR spectroscopy is given and the resolution of current spectrometers is illustrated by FTIR spectra of CO, CO2 OCS, N2O, CS2, and CH4 and its isotopomers. The computational tools necessary to analyze FTIR spectra are described briefly. As examples of rovibrational analysis of more complex spectra, selected molecules CHCl2F, CDBrClF, pyridine (C6H5N) and pyrimidine (C4H4N2), and naphthalene (C10H8) are discussed. The spectrum of CHCl2F, a fluorochlorocarbon, is of interest for a better understanding of the chemistry of the Earth's atmosphere. It also possesses an isotopically chiral isotopomer CH35Cl37ClF analyzed in natural abundance. CDBrClF is a chiral molecule and therefore the analysis of its rovibrational spectra provides the basis for carrying out further experiments toward the detection of molecular parity violation. The analyses of the pyridine, pyrimidine, and naphthalene FTIR spectra illustrate the potential of the new generation of FTIR spectrometers in the study of spectra and rovibrational dynamics of aromatic systems and molecules of potential biological interest. In particular, naphthalene is a prototype molecule useful in gaining an understanding of the unidentified infrared bands (UIBs) detected in several interstellar objects. Keywords: high-resolution spectroscopy; resonance; FTIR spectroscopy; chiral molecules; aromatic molecules; infrared spectroscopy; isotopes; isotopomers; symmetry; asymmetric tops; synchrotron light sources; CDFClBr; CHFClBr; CHFCl2; fluorohydrocarbons, methane, CH2D2; CHD3; CH3D; CH4; naphthalene; pyridine; pyrimidine; benzene; carbondioxide; CO2; CO; OCS; N2O; CS2

One-step synthesis of uniform silver nanoparticles capped by saturated decanoate: direct spray printing ink to form metallic silver films

Abstract: The one-step synthesis and spectroscopic characterizations of size-controlled silver nanoparticles are described. The transmission electron microscopy (TEM), nuclear magnetic resonance (NMR), Fourier transform infrared spectroscopy (FT-IR), thermal gravimetric-mass analysis (TGA-MS) and X-ray photoelectron spectroscopy (XPS) techniques were used to characterize the decanoate-protected silver nanoparticles. TEM analysis showed that spherical nanoclusters of 7.52 ± 0.57 nm were produced. Furthermore, the particle sizes are uniform with a narrow size distribution. For all samples, Ag 3d5/2 and 3d3/2 components appeared at 368.5 and 374.5 eV, respectively, in the XPS spectrum; these values compare very well with the typical values of carboxylate-protected Ag nanoparticles. A thermal analysis mass spectrometer was used to analyze the desorption behavior of decanoate-protected nanoparticles. From the desorption maximum temperatures of 181 and 263 °C, activation energies of 27.2 and 32.2 kcal mol−1 for the desorption processes in the Ag MPCs were obtained, assuming a first-order reaction and using a pre-exponential factor of 1 × 1013 s−1. A specific resistivity of 6.097 μΩ cm for the silver metal film (0.7 μm) on a Si wafer can be produced simply by thermal annealing of an Ag monolayer-protected clusters film under an atmosphere of 90% N2–10% H2 at 300 °C for 1 h.