We investigate the sensitivity of femtosecond Fourier transform two-dimensional infrared spectroscopy to protein secondary structure with a study of antiparallel beta-sheets. The results show that 2D IR spectroscopy is more sensitive to structural differences between proteins than traditional infrared spectroscopy, providing an observable that allows comparison to quantitative models of protein...

SnCl4/nano-sawdust was prepared as a carbohydrate-based catalyst containing of tin bearing cellulose units. The catalyst was characterized by X-ray diffraction (XRD), fourier transform infrared spectroscopy (FT-IR), field emission scanning electron microscopy (FESEM) and energy dispersive X-ray spectroscopy (EDS). The catalyst was applied successfully as a readily available, inexpensive, biodeg...

A method of two-dimensional infrared (2D IR) spectroscopy called relaxation-assisted 2D IR (RA 2DIR) is proposed that utilizes vibrational energy relaxation transport in molecules to enhance cross-peak amplitudes. This method substantially increases the range of distances accessible by 2D IR and is capable of identifying long-range connectivity patterns in molecules. RA 2DIR is illustrated in i...

Proteins are molecules that behave in beautiful and astounding ways in the course of their biological function, and all biological processes involve protein conformational changes. These processes might be enzyme catalysis, transport and signaling, dynamic scaffolding for structures, charge transfer, or mechanical or electrical energy transduction. Our view of such processes is colored by the m...

Most vapor molecules have a unique absorption spectrum in the mid-IR region, so this range is of particular interest for trace gas analysis and chemical sensing. And quantum cascade (QC) lasers are ideal candidate light sources for mid-IR spectroscopy: Their emission wavelength reaches from the midto the far-IR with good power efficiency. QC lasers are based on the intersubband transitions betw...

We present resonant two-photon ionization (R2PI), UV-UV, and IR-UV double resonance spectra of xanthine seeded in a supersonic jet by laser desorption. We show that there is only one tautomer of xanthine which absorbs in the wavelength range of 36 700 to 37 700 cm(-1). The IR-UV double resonance spectrum shows three strong bands at 3444, 3485, and 3501 cm(-1), all of which we assign as N-H stre...

We have used a heated 2 cm × 1 mm SiC microtubular (μtubular) reactor to decompose acetaldehyde: CH(3)CHO + Δ → products. Thermal decomposition is followed at pressures of 75-150 Torr and at temperatures up to 1675 K, conditions that correspond to residence times of roughly 50-100 μs in the μtubular reactor. The acetaldehyde decomposition products are identified by two independent techniques: v...