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Topic: Vibrational spectroscopy


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  Physicists identify molecules by vibrational signatures
Vibrational spectroscopy is the study of the energy (which for scientists identifies the frequency) of the vibration of molecular bonds.
The vibration is unique for each possible arrangement of atoms in a molecule, and in the language of quantum mechanics, each vibration has a characteristic "energy level." An electron whose energy matches or exceeds that of a vibrational energy level in a molecule can pass through the molecule more easily.
For years the only useful way to do this type of vibrational spectroscopy was to pass a current through a thin film of a substance and vary the voltage and, therefore, the energy of the electrons in the current.
www.news.cornell.edu /Chronicle/98/6.25.98/vibrating_molecule.html   (857 words)

  
 Raman Spectroscopy Tutorial
Vibrational Raman spectroscopy in this broad sense is an extraordinarily versatile probe into a wide range of phenomena ranging across disciplines from physical biochemistry to materials science.
The scattered intensity from non-totally symmetric vibrations is 3/4 as strong in the plane perpendicular to the plane of polarization of the incident light as in the plane parallel to it.
Resonance Raman spectroscopy is also a major probe of the chemistry of fullerenes, polydiacetylenes and other "exotic" molecules which strongly absorb in the visible.
www.kosi.com /raman/resources/tutorial   (2108 words)

  
 RamanBasics   (Site not responding. Last check: 2007-11-05)
The vibrational modes of a molecule can best be modeled by assuming that the compound is composed of atoms (balls) joined by chemical bonds composed of springs (rather than the traditional sticks).
Vibrational modes for the molecule are a function of the orientation of its atoms and bonds, the atomic mass of the atoms, bond order and hydrogen bonding, among other factors.
Some of the energy from the incident photon is used by the molecule to excite it to higher level vibrational and rotational states, the rest is emitted as a photon of reduced energy.
www.sas.upenn.edu /~crulli/RamanBasics.html   (1004 words)

  
 Publications of the group 2D Vibrational Spectroscopy - Sander Woutersen
Nonlinear time-resolved vibrational spectroscopy is used to compare spectral broadening of the amide I band of the small peptide trialanine with that of N-methylacetamide, a commonly used model system for the peptide bond.
Two-dimensional vibrational spectroscopy is applied to the amide I mode of trialanine and two of its isotopomers dissolved in heavy water.
A femtosecond mid-infrared pump-probe study of the vibrational and orientational dynamics of the OH-stretching mode of HDO dissolved in D2O is presented.
www.amolf.nl /research/2d/publications.html   (4596 words)

  
 Experiment 9. Rotational-Vibrational Spectroscopy. Introduction
The last term accounts for the interaction between the vibration and rotation of the molecule; as the molecule vibrates, the moment of inertia changes and the rotation of the molecule is affected.
Since the reduced mass affects the vibrational and rotational behavior or a molecule, the energy of its transitions are affected.
Group theory shows that each vibrational coordinate and each vibrational energy level, along with its associated wavefunction, must have a symmetry corresponding to one of the symmetry species of the molecular point group.
www.chemistry.nmsu.edu /studntres/chem435/Lab9/intro.html   (3215 words)

  
 5.4 Vibrational Spectroscopy
Vibrational spectroscopy provides the most definitive means of identifying the surface species generated upon molecular adsorption and the species generated by surface reactions.
This states that only those vibrational modes which give rise to an oscillating dipole perpendicular (normal) to the surface are IR active and give rise to an observable absorption band.
The selection rules that determine whether a vibrational band may be observed depend upon the nature of the substrate and also the experimental geometry: specifically the angles of the incident and (analysed) scattered beams with respect to the surface.
www.chem.qmul.ac.uk /surfaces/scc/scat5_4.htm   (1431 words)

  
 Infrared Spectroscopy
Vibrational modes are often given descriptive names, such as stretching, bending, scissoring, rocking and twisting.
The exact frequency at which a given vibration occurs is determined by the strengths of the bonds involved and the mass of the component atoms.
The number of observed absorptions may be increased by additive and subtractive interactions leading to combination tones and overtones of the fundamental vibrations, in much the same way that sound vibrations from a musical instrument interact.
www.cem.msu.edu /~reusch/VirtualText/Spectrpy/InfraRed/infrared.htm   (1310 words)

  
 Dynamics: Infrared Spectroscopy
Vibrational spectroscopy (or infrared spectroscopy) measures transitions from one molecular vibrational energy level to another, and requires radiation from the infrared portion of the electromagnetic spectrum.
The energy of a vibration is measured by its amplitude (the distance moved by the atoms during the vibration), so the higher the vibrational energy, the larger the amplitude of the motion.
The frequency of light required to cause a transition for a particular vibration is equal to the frequency of the vibration, so we may measure the vibrational frequencies by measuring the frequencies of light absorbed by the molecule.
www.wpi.edu /Academics/Depts/Chemistry/Courses/General/infrared.html   (3404 words)

  
 MIT Spectroscopy - Biomedical Research Projects
Vibrational spectroscopy is a powerful technique to study hydrogen bonded systems because the frequency of the intramolecular OH stretching vibration is particularly sensitive to a molecule's hydrogen bonding environment.
We are using nonlinear infrared spectroscopy to follow time dependent changes in the OH stretching frequency of HOD in D 2 O. Molecular dynamics simulations serve to help connect measured spectroscopic observables with the ultrafast microscopic dynamics of liquid water.
Development of Nonlinear Infrared Spectroscopy: Nonlinear IR spectroscopy is rapidly becoming one of the leading methods of determining transient structures of complex molecules in solution.
web.mit.edu /spectroscopy/research/phys_research/lrf_09_tokmakoff.html   (489 words)

  
 Raman Spectroscopy
Raman Spectroscopy is based on the Raman effect, which is the inelastic scattering of photons by molecules.
The energy increase or decrease from the excitation is related to the vibrational energy spacing in the ground electronic state of the molecule and therefore the wavenumber of the Stokes and anti-Stokes lines are a direct measure of the vibrational energies of the molecule.
For highly symmetric polyatomic molecules possessing a center of inversion (such as benzene) it is observed that bands that are active in the IR spectrum are not active in the Raman spectrum (and vice-versa).
carbon.cudenver.edu /public/chemistry/classes/chem4538/raman.htm   (2082 words)

  
 Infrared spectroscopy - Wikipedia, the free encyclopedia
Infrared spectroscopy (IR Spectroscopy) is the subset of spectroscopy that deals with the Infrared part of the electromagnetic spectrum.
The resonant frequencies or vibrational frequencies are determined by the shape of the molecular potential energy surfaces, the masses of the atoms and, eventually by the associated vibronic coupling.
Infrared spectroscopy is widely used in both research and industry as a simple and reliable technique for measurement, quality control, and dynamic measurement.
en.wikipedia.org /wiki/Infrared_spectroscopy   (1316 words)

  
 David Y. Gin, Chemistry   (Site not responding. Last check: 2007-11-05)
We have used it to study vibrational energy flow in simple liquids such as acetonitrile, water, and methanol.
Vibrational Sum-frequency Generation (SFG) is a powerful technique for obtaining the vibrational spectrum of molecules at surfaces and interfaces.
Ultrafast vibrational spectroscopy is used to study nanoenergetic materials that have coherent structures organized on nanometer-length scales.
www.scs.uiuc.edu /chem/gdlot2.html   (553 words)

  
 Infrared Spectroscopy   (Site not responding. Last check: 2007-11-05)
For example, on the “Vibrations of Molecules” page it was stated that a non-linear polyatomic molecule would use the 3N-6 formula to determine the number of vibrational modes.
This vibrational mode IS IR active and would be observed on a spectrum.
Vibrational frequencies are absorptions of IR radiation and can be correlated directly to bonds within a compound.
www.sas.upenn.edu /~rebryant/Infrared_Spectroscopy.html   (550 words)

  
 Vibrational Spectroscopy   (Site not responding. Last check: 2007-11-05)
Infrared spectroscopy (IR Spectroscopy) uses the infrared portion of the electromagnetic spectrum.
Laser light is used as the source, and causes the atoms in molecules to vibrate.
Laboratory spectroscopy using long-wavelength infrared light to identify and characterize target molecules.
www.intertek-cb.com /newsitetest/news/vibrationalspectroscopy.shtml   (284 words)

  
 Vibrational Spectroscopy
The spectroscopy group at the IBI-2 uses a wide variety of spectroscopic techniques for the investigation of biological samples.
This introduces major difficulties in applying infrared spectroscopy on those samples because of a strong water absorbance in the interesting regions of the spectrum.
Vibrational spectroscopy of proteins detects changes in the intramolecular structure and therefore has to deal with a huge amount of information.
www.fz-juelich.de /ibi/ibi-2/methods/vibr_spec   (431 words)

  
 Vibrational Spectroscopy | Spectroscopy | Infrared Spectroscopy | IR Spectroscopy | Axiom Analytical   (Site not responding. Last check: 2007-11-05)
We thus must fall back on less elegant means of signal transmission if we wish to apply mid-infrared spectroscopy to situations in which the sample can not conveniently be brought to the spectrometer.
This is quite useful in estimating the performance of lightguides used in vibrational spectroscopy.
Spectroscopy of Surface Films and Powders Using a Metal Light Pipe’, Applied Spectroscopy, 41 553 (1987).
www.goaxiom.com /an-917.html   (3067 words)

  
 Vibrational Spectroscopy.   (Site not responding. Last check: 2007-11-05)
Yasuyuki Nagasoe, Hirofumi Okabayashi, Motoko Abe, Julian Eastoe, Charmian J. O'Connor, Vibrational spectra of Aerosol-OT homologous sodium dialkylsulfosuccinates - normal coordinate analyses of sodium diethylsulfosuccinate and sodium dimethylsulfosuccinate and their application to longer homologues, Vibrational Spectroscopy 23 (2) (2000) pp.
Tetyana Stepanenko, Leszek Lapinski, Maciej J. Nowak, Ludwik Adamowicz, Infrared spectra of syn and anti isomers of benzaldoxime and pyridine-4-aldoxime: an experimental matrix isolation and theoretical density functional theory study, Vibrational Spectroscopy 26 (1) (2001) pp.
Elif Akalin, Sevim Akyüz, Theoretical study of IR spectra of paraphenylenediamine, Vibrational Spectroscopy 22 (1-2) (2000) pp.
www1.elsevier.com /cdweb/journals/09242031/viewer.htt?viewtype=authors   (593 words)

  
 Vibrational Spectroscopy Research - Strouse Group Research   (Site not responding. Last check: 2007-11-05)
This packing motif is reminiscent of self-assembled monolayer structures on single crystals and liquid crystal structures, in which molecular level interactions dominate the packing assembly thermodynamics.
We have probed the the surface packing of the passivant by correlating phase transition behavior of the organic layer using attenuated total reflection infrared spectroscopy (ATR-IR) coupled with differential scanning calorimetry (DSC).
Analysis by UV-Vis and FTIR spectroscopy allows direct analysis of the oxyanion interaction at the surface of the Au nanomaterial.
www.chem.fsu.edu /editors/strouse/vibrational.html   (579 words)

  
 Biomedical Vibrational Spectroscopy (BO16)
Vibrational spectroscopy provides molecular specific information that has long been used in the field of biochemistry.
Recent technological advances have led to the application of vibrational spectroscopy to address biological and biomedical problems.
This conference will encompass the applications of vibrational spectroscopy to solving biological and biomedical problems ranging from the macroscopic to the submicroscopic level.
www.spie.org /web/meetings/calls/pw01/confs/BO16.html   (147 words)

  
 VIbrational Spectroscopy   (Site not responding. Last check: 2007-11-05)
Infrared spectroscopy is used to study molecular vibrations.
While a given functional group typically has a few characteristic (well-defined) vibrational frequencies (most of which give strong absorption peaks in the infrared spectrum), the exact frequency of each vibration depends on the details of its interaction with its molecular environment.
The goal of this project is the identification and exploration of smaller and subtler vibrational signatures of intra- and intermolecular hydrogen bonding interactions.
www.hamline.edu /~dbeseman/research/FTIR.html   (192 words)

  
 Group Theory and Vibrational Spectroscopy
The complex vibrations of a molecule are the superposition of relatively simple vibrations called the normal modes of vibration.
During infrared spectroscopy experiments we observe transitions between vibrational energy levels of a molecule induced by the absorption of infrared (IR) radiation.
In Raman spectroscopy, vibrational transitions occur during the scattering of light by molecules.
www.chem.plu.edu /pchem/chem342/GroupTheor.htm   (1151 words)

  
 Wilson Ho
Single-molecule Vibrational Spectroscopy and Microscopy: CO on Cu(001) adn Cu(110), L.J. Lauhon and W. Ho, Phys.
Single Molecule Chemistry and Vibrational Spectroscopy: Pyridine and Benzene on Cu(001), L.J. Lauhon and W. Ho, J. Phys.
Structural Determination by Single-Molecule Vibrational Spectroscopy and Microscopy: Contrast Between Copper and Iron Carbonyls, H.J. Lee and W. Ho, Phys.
www.lassp.cornell.edu /lassp_data/whoarsmisdc.html   (482 words)

  
 Faculty of Chemistry Jagiellonian University - research groups
We use the infrared absorption spectroscopy and Raman scattering spectroscopy to study the molecular structure of bioactive compounds, their derivatives and complexes with metal ions.
Studies on molecular structures of hydroxamic acids and their transition metal ions based on vibrational spectroscopy, NMR and quantum-chemical calculations.
Vibrational studies on differences in the paper structure due to oxidation and hydrolysis of cellulose.
www.chemia.uj.edu.pl /zespol_en.php?id=10048   (3537 words)

  
 Vibrational spectroscopy   (Site not responding. Last check: 2007-11-05)
Fourier transform infrared (FTIR) spectroscopy is a characterization technique widely used in physics, chemistry, and biology.
The central component of an FTIR spectrometer, shown in the left figure, is a Michelson interferometer.
Local vibrational modes (LVMs) are localized in real and frequency space, and typically give rise to sharp infrared absorption peaks at liquid-helium temperatures.
www.physics.wsu.edu /Research/High-pressure/vibratio.htm   (243 words)

  
 2000 GRC on Vibrational Spectroscopy and Molecular Dynamics
The "Vibrational Gordon Conference" has an established tradition of addressing multi-disciplinary topics including advances, recent developments and novel applications of vibrational spectroscopy for molecular systems.
This year's meeting features world-renowned invited speakers chosen to attract graduate students, postdoctoral researchers and starting investigators interested in using Infrared, Raman and Neutron scattering vibrational spectroscopies in their careers.
It is hoped that these topical sessions will enable contributors and participants engaged in modern applications and uses of vibrational spectroscopy to "cross-fertilize" and that this venue will lead to exciting future scientific developments and collaborations in this expanding and active field.
www.grc.org /programs/2000/vibrat.htm   (724 words)

  
 Vibrational spectroscopy - Wikipedia, the free encyclopedia
The vibrational states of a molecule can be probed in a variety of ways.
The most direct way is infrared spectroscopy because vibrational transitions typically require an amount of energy that corresponds to the infrared region of the spectrum.
However, Raman spectroscopy, vibrational circular dichroism and electron energy loss spectroscopy also provide vibrational information.
en.wikipedia.org /wiki/Vibrational_spectroscopy   (97 words)

  
 JCE 1999 (76) 1276 [Sep] An Interactive Dry Lab Introduction to Vibrational Raman Spectroscopy Using Carbon ...
An introduction to vibrational Raman spectroscopy is presented in a dry lab format that utilizes free software to add interactivity.
Relevant IR and Raman spectra of carbon tetrachloride are systematically compared and analyzed on the basis of a broad review of general vibrational spectroscopy.
Included in the discussion are the classic physical and group theory descriptions of IR and Raman spectroscopy, depolarization measurements, the application of Boltzmann analysis for sample temperature calculations, isotope effects visible under high-resolution conditions, and a full description of the Raman instrument and conditions used to acquire all spectra.
jchemed.chem.wisc.edu /Journal/issues/1999/sep/abs1276.html   (336 words)

  
 VIBRATIONAL SPECTROSCOPY
Vibrational Spectroscopy provides a vehicle for the publication of original research in vibrational spectroscopy.
It covers infrared, near-infrared and Raman spectroscopies and publishes papers dealing with developments in applications, theory, techniques and instrumentation.
The topics covered by the journal include: Sampling techniques - including diffuse reflectance spectroscopy, reflection-absorption spectroscopy, and photoacoustic spectroscopy; Vibrational spectroscopy coupled with separation techniques; Instrumentation (Fourier transform, conventional and laser based); Data manipulation; Expert systems for identification and structure elucidation; Spectra-structure correlation and group frequencies.
www.efluids.com /efluids/pages/j_midpages/vibrational_spectroscopy.htm   (110 words)

  
 2004's 50th GRC on Vibrational Spectroscopy
The 50th anniversary meeting in this series includes topical sessions dealing with many aspects of contemporary vibrational spectroscopy, both fundamental and applied, and a festive anniversary session which will include talks aimed at providing a view of the development of this field looking backward at its history and forward to its future.
"Vibrational spectroscopy of OCS and OCS complexes with molecular hydrogen in helium clusters"
"Vibrational Spectroscopy at Cryogenic Temperatures: From the Laboratory to the Ends of the Universe"
www.grc.uri.edu /programs/2004/vibrat.htm   (447 words)

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