Generation Spectroscopy (generation + spectroscopy)

Distribution by Scientific Domains

Kinds of Generation Spectroscopy

  • sum-frequency generation spectroscopy


  • Selected Abstracts


    Second Harmonic Generation Spectroscopy as a Method for In Situ and Online Characterization of Particle Surface Properties

    PARTICLE & PARTICLE SYSTEMS CHARACTERIZATION, Issue 5 2006
    Lars Schneider
    Abstract Non-linear optical spectroscopy is a recently established technique used in the investigation of the properties of colloidal interfaces. Since it is an optical method it is non-invasive, can be applied in situ, and can provide real time resolution. Until recently, only a few papers concerning this method have been published, but these all show the great potential and the large field of applications of the technique. This paper gives an overview of the fundamentals of the technique and its possible applications. [source]


    Mechanistic Studies by Sum-Frequency Generation Spectroscopy: Hydrolysis of a Supported Phospholipid Bilayer by Phospholipase,A2,

    ANGEWANDTE CHEMIE, Issue 13 2010
    Yujin Tong
    Die Strukturänderungen bei der durch das PLA2 -Enzym katalysierten Hydrolyse einer DPPC-Doppelschicht und der Mechanismus dieser Reaktion wurden auf molekularer Ebene für jede Schicht (rot und schwarz) der trägerfixierten Lipiddoppelschicht mithilfe von Summenfrequenzspektroskopie untersucht (DPPC=Dipalmitoylphosphatidylcholin). [source]


    In Situ Characterization of Thermo-Responsive Poly(N -Isopropylacrylamide) Films with Sum-Frequency Generation Spectroscopy

    CHEMPHYSCHEM, Issue 7 2010
    Volker Kurz
    Abstract The thermo-responsive behaviour of thiol modified poly(N -isopropylacrylamide) (pNIPAM) films immobilized on gold are probed by in situ broadband sum-frequency generation (SFG) spectroscopy. The pNIPAM films were prepared by atom transfer radical polymerization (ATRP) using a nitro-biphenyl-thiol (NBT)-SAM on a polycrystalline gold surface as a substrate. Additionally, Raman and infrared reflection absorption spectroscopy (IRRAS) are applied to spin-coated pNIPAM films. Molecular groups involved in the reorientation and disordering of the polymer chains during the LCST (lower critical solution temperature) transition of pNIPAM are identified. The characteristic vibrations of the CH3 groups show a gradual reorientation of the isopropyl groups within the pNIPAM film and instantaneous reorientation of the outermost CH3 groups around 32,°C. [source]


    Identification of chemical species of fluorescein isothiocyanate isomer,I (FITC) monolayers on platinum by doubly resonant sum-frequency generation spectroscopy

    JOURNAL OF RAMAN SPECTROSCOPY, Issue 11 2008
    Toshiki Maeda
    Abstract Doubly resonant sum-frequency generation (DR-SFG) spectroscopy of fluorescein-4-isothiocyanate isomer-I (FITC) monolayers on platinum was performed. Vibrational spectra of the monolayers for the IR wavenumber of 1750,1450 cm,1 were measured with visible probes ranging from 431 to 582 nm. Two vibrational bands at 1643 and 1610 cm,1 were observed, and their DR-SFG excitation profiles displayed different shapes. By rinsing the monolayers with an alkaline solution, the smaller wavenumber band disappeared and the larger wavenumber band gained intensity. On the basis of the spectral response to the rinsing, we concluded that the FITC molecules existed on platinum as deprotonated and protonated forms; the former corresponds to the 1643 cm,1 band and the latter to the 1610 cm,1 band. The deprotonated form was assigned to an anionic surface species, and the protonated form to a neutral surface species by comparing the DR-SFG excitation profiles with electronic absorption spectra of the protolytic forms of fluorescein in an aqueous solution (Sjöback R et al., Spectrochimica Acta A 1995; 51: L7,L21). The results demonstrate that the measurement of DR-SFG excitation profiles is a useful technique to identify chemical species of monolayers on metal surfaces. Copyright © 2008 John Wiley & Sons, Ltd. [source]


    Time-resolved coherent Raman and sum-frequency generation spectroscopy with wavelength-tunable, short-pulse, photonic-crystal fiber light sources

    JOURNAL OF RAMAN SPECTROSCOPY, Issue 8 2007
    A. M. Zheltikov
    Abstract Photonic-crystal fibers deliver frequency-tunable radiation within the wavelength range stretching from the ultraviolet to the near-infrared with output pulse widths from tens of femtoseconds to a few picoseconds and peak powers from a few watts to several megawatts, suggesting a convenient, efficient, and compact fiber format of short-pulse sources for time-resolved nonlinear spectroscopy and microscopy. Here, we examine the potential of photonic-crystal fiber light sources for time-resolved studies of ultrafast population and coherence relaxation dynamics in molecular systems using coherent anti-Stokes Raman scattering and two-photon-resonant sum-frequency generation. Copyright © 2007 John Wiley & Sons, Ltd. [source]


    Second harmonic generation spectroscopy on Si surfaces and interfaces

    PHYSICA STATUS SOLIDI (B) BASIC SOLID STATE PHYSICS, Issue 8 2010
    Kjeld Pedersen
    Abstract Optical second harmonic generation (SHG) spectroscopy studies of Si(111) surfaces and interfaces are reviewed for two types of systems: (1) clean 7,×,7 and -Ag reconstructed surfaces prepared under ultra-high vacuum conditions where surface states are excited and (2) interfaces in silicon-on-insulator (SOI) structures and thin metal films on Si surfaces where several interfaces contribute to the SHG. In all the systems resonances are seen at interband transitions near the bulk critical points E1 and E2. On the clean surfaces a number of resonances appear below the onset of bulk-like interband transitions that can be referred to excitations of dangling bond surface states. Adsorption of oxygen leads to formation of a new surface resonance. Such resonances appearing in the region between the bulk critical points E1 and E2 are also shown to be important for Si/oxide interfaces in SOI structures. Finally, examples of spectroscopy on layers buried below thin Ag and Au films are given. [source]