Single color pump-probe and photon-echo experiments have been performed on the COstretching mode of W(CO)6 at about 1983 cm-1 in various liquids and solidenvironments. Combined with absorption data, the measured T1 and T2 times suggestthe following conclusions: in all liquids studied, the IR absorption band ishomogeneously broadened, whereas, inhomogeneous broadening is observed in solidmatrices and in a xerogel. At low temperature, the echo decay is much faster in methanethan in argon host.

C.  Cr&#233;pin

M.  Broquier

H.  Dubost

D.  L&#39;hermite

A.  Tramer

J. P. Galaup

J. M. Berset

J. M. Ortega

Vibrational Dynamicsin Molecular Condensed PhasesWith The Clio Free Electron Laser

Time-resolved infrared spectroscopy using step-scan FTIR has been developed as anapproach to study transient inorganic species with lifetimes ranging from ca. 200nanseconds to several microseconds. This approach has been applied to a variety ofproblems arising following laser excitation of d6 polypyridine complexes in solution, andseveral examples are shown to demonstrate the utility of this experiment.

Jon R. Schoonover

Time-Resolved, Step-Scan FtirStudies Of Excited States Of d6Metal Polypyridine Complexes

A method for estimating vibrational quantum numbers of vibrationally excitedtransients in solution is proposed. In this method, we calculate anti-Stokes Ramanexcitation profiles (REPs) which are characteristic of the initial vibrational statesinvolved in the Raman process, and compare them with observed anti-Stokes intensities.We have applied this method to vibrationally hot molecules of canthaxanthin in the Sostate and those of trans-stilbene in the S1 state. For canthaxanthin, it has been found thatthe vibrationally excited transients are for the most part on the &#957;&#61;1 level of the C&#9552;Cstretching mode, and that excess vibrational energy is statistically distributed among allintramolecular vibrational modes. As for S1 stilbene, vibrational transients are shown tobe mostly on the &#957;&#61;1 level for two vibrational modes examined, while the excessvibrational energy is probably localised on the olefinic C&#9552;C stretching mode.

Hiromi  Okamoto

Takakazu  Nakabayashi

Mitsuo  Tasumi

Picosecond Anti-Stokes RamanExcitation Profiles as a Methodfor Investigating VibrationallyExcited Transients

Using time-resolved step-scan FTIR spectroscopy, it has become possible to identify twodifferent M states in the 5 to 300 &#956;s time range, which clearly differ from the MN state.The identification has become possible by measuring a pure BR&#8594;KL differencespectrum at 100 ns, which can be used to correct for the contributions of thisintermediate in the later difference spectra. The subtraction of the later correcteddifference spectra thus represent L&#8594;M1, M2 difference spectra with varying relativeamount of the two M states. The comparison of these spectra clearly reveals differencesin the amide-II spectral range, and possibly also in the amide-I range. From theseobservations it can be concluded that the two M states do not differ in the chromophorestructure but in the protein structure.

Olaf  Weidlich

Christoph  R&#246;dig

 Friedrich  Siebert

Time-Resolved Step-Scan FtirInvestigations on the M1&#8594;M2Transition in the Light-DrivenProton Pump Bacteriorhodopsin

Transient picosecond infrared (IR) spectra of the OH and NH-stretch (v&#61;0&#8211;1) absorptionbands of several hydrogen-bonded complexes have been investigated. Solutions of1:1 complexes of weak acids (methanol, triethylsilanol and pyrrole, &#60; 0.1 mol/dm3) andbases (acetonitrile, pyridine and tetrahydrofuran, &#60; 2 mol/dm3) in CCl4 at 295 K wereinterrogated with IR excitation and broadband probing. Lorentzian-shaped absorptionbands are uniformly bleached while those with near-Gaussian bandshapes producetransient spectral holes. These results indicate a base functionality and hydrogen-bondstrength dependence for determining the broadening mechanisms of these absorptions.

S. M. Arrivo

V. D. Kleiman

W. T. Grubbs

T. P. Dougherty

E. J. Heilweil

Infrared Spectral Hole Burningof 1:1 Hydrogen-Bonded Complexesin Solution

We present a theoretical description of the dynamics of vibrational wave packets in the<mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"><mml:mrow><mml:msub><mml:mtext>1</mml:mtext><mml:mi>g</mml:mi></mml:msub></mml:mrow></mml:math> state of Xe2. As an illustration, a simulation of a picosecond pump excitation-probeionization laser experiment is carried out. The initial wavepacket is calculated using anexplicit modelling of the short-pulse excitation process and propagated for up to160 picoseconds. Evidence of fractional and full revivals of the wavepacket has beenfound and analyzed. The time delayed ionization signal is simulated using first orderperturbation theory and shows clear oscillations corresponding to the temporaldevelopment of the wavepacket.

J. F. Castillo

K. L. Reid

A Theoretical Study of the
Dynamics of Vibrational Wave
Packets in the <svg style="vertical-align:-5.76988pt" height="18.1" version="1.1" viewBox="0 0 15.675 18.1" width="15.675" xmlns:xlink="http://www.w3.org/1999/xlink" xmlns="http://www.w3.org/2000/svg"><g transform="matrix(.017,-0,0,-.017,.062,10.863)"><path id="x31" d="M384 0h-275v27q67 5 81.5 18.5t14.5 68.5v385q0 38 -7.5 47.5t-40.5 10.5l-48 2v24q85 15 178 52v-521q0 -55 14.5 -68.5t82.5 -18.5v-27z" /></g><g transform="matrix(.012,-0,0,-.012,8.225,14.938)"><path id="x1D454" d="M546 430q-14 -33 -37.5 -140t-38.5 -209q-29 -195 -156 -289q-29 -21 -70 -37t-78 -16q-62 0 -102.5 37t-40.5 69q0 27 26 48q19 15 25 -3q13 -43 46.5 -69t87.5 -26q55 0 83 21q29 22 50 65t43 140q14 64 29 163h-2q-55 -81 -149 -152q-59 -44 -102 -44q-23 0 -43.5 30&#xA;t-20.5 85q0 74 32.5 145.5t84.5 117.5q40 35 100 58.5t117 23.5q21 0 65 -8q30 -6 44 -6zM456 386q-40 16 -81 16q-29 0 -64 -13q-42 -17 -85 -97q-19 -36 -31.5 -86t-12.5 -86q0 -64 30 -64q20 0 52.5 21t60.5 52q74 81 95 123q26 62 36 134z" /></g></svg> State Of Xe2

Replacing the chromophore of bacteriorhodopsin with chemically modified retinalanalogs which cannot isomerize, allows to measure directly side effects from the laserpulse used for sample excitation in step-scan FT-IR measurements. Comparison withstatic temperature difference spectra and temperature-jump experiments shows that theobserved effects can mainly be attributed to heating of the sample by the laser pulse. Thesize of resulting spectral changes is compared to difference bands of the photoreaction.

C.  R&#246;dig

H.  Georg

F.  Siebert

I.  Rousso

M.  Sheves

Temperature Effects Of ExcitationLaser Pulses During Step-ScanFT-IR Measurements

Third- and fifth-order impulsive stimulated Raman scattering experiments are performedto study low-frequency intermolecular vibrations in CS2/pentane binary mixtures. Thechanges of the optical Kerr effect response cannot be assigned unequivocally to a singlemicroscopic process. In particular, the homogeneous and inhomogeneous line broadeningmechanisms cannot be determined. Temporally two-dimensional Raman scatteringexperiments indicate that the correlation time of fluctuations of the intermolecularpotential decreases upon dilution. The experimental results give evidence of strongcoupling between the ultrafast coherent vibrations and the slow reorientational diffusion.

Thomas  Steffen

Satoru  Nakashima

Koos  Duppen

Temporally Two-DimensionalFifth-Order Raman Scatteringon Intermolecular Vibrationsin Cs2/Pentane Binary Mixtures

Via intense ps-excitation of the OH-stretching vibration of ethanol diluted in CCl4 wesucceed in spectral hole burning within the inhomogeneously broadened oligomer band.The lifetime of the transient hole and the v&#61;1-level of the OH-stetch of associatedethanol molecules are determined to be about 1.2 and 1.7 ps, respectively. Furtherdynamical features are discussed which give evidence for energy migration within theH-bonded ethanol chains and subsequent breaking of the oligomers into shorterfragments.

R.  Laenen

C.  Rauscher

Spectral Hole Burning andEvidence for Vibrational EnergyMigration of H-Bonded MoleculesObserved With Transient InfraredSpectroscopy

Exciplex formation dynamics of photoexcited copper(II) tetrakis (4-N-methylpyridyl)porphyrin (Cu(II)(TMpy-P4)) with added poly(dA-dT)2 and poly(dG-dC)2 has beeninvestigated by using femtosecond transient absorption and nanosecond and picosecondtransient Raman spectroscopic methods. It was observed that the decay time constant ofthe exciplex is strongly dependent on the polynucleotide and has a strong correlationwith the appearance of new transient Raman bands.

Sae Chae Jeoung

Hyo Soon Eom

Dongho  Kim

Transient Absorption and RamanStudies on Exciplex FormationDynamics of PhotoexcitedCu(II)(TMpy-P4) With SyntheticPolynucleotide

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Laser Chemistry | Hindawi

Laser Chemistry

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Papers are published upon acceptance, regardless of the Special Issue publication date.

Laser Chemistry

Proceedings of the Eighth Conference on Time-Resolved Vibrational Spectroscopy

Proceedings of the Eighth Conference on Time-Resolved Vibrational Spectroscopy

Articles

Vibrational Dynamics in Molecular Condensed Phases With The Clio Free Electron Laser

Time-Resolved, Step-Scan Ftir Studies Of Excited States Of d⁶ Metal Polypyridine Complexes

Picosecond Anti-Stokes Raman Excitation Profiles as a Method for Investigating Vibrationally Excited Transients

Time-Resolved Step-Scan Ftir Investigations on the M₁→M₂ Transition in the Light-Driven Proton Pump Bacteriorhodopsin

Infrared Spectral Hole Burning of 1:1 Hydrogen-Bonded Complexes in Solution

A Theoretical Study of the Dynamics of Vibrational Wave Packets in the State Of Xe₂

Temperature Effects Of Excitation Laser Pulses During Step-Scan FT-IR Measurements

Temporally Two-Dimensional Fifth-Order Raman Scattering on Intermolecular Vibrations in Cs₂/Pentane Binary Mixtures

Spectral Hole Burning and Evidence for Vibrational Energy Migration of H-Bonded Molecules Observed With Transient Infrared Spectroscopy

Transient Absorption and Raman Studies on Exciplex Formation Dynamics of Photoexcited Cu(II)(TMpy-P4) With Synthetic Polynucleotide

Laser Chemistry

Proceedings of the Eighth Conference on Time-Resolved Vibrational Spectroscopy

Proceedings of the Eighth Conference on Time-Resolved Vibrational Spectroscopy

Articles

Vibrational Dynamics in Molecular Condensed Phases With The Clio Free Electron Laser

Time-Resolved, Step-Scan Ftir Studies Of Excited States Of d6 Metal Polypyridine Complexes

Picosecond Anti-Stokes Raman Excitation Profiles as a Method for Investigating Vibrationally Excited Transients

Time-Resolved Step-Scan Ftir Investigations on the M1→M2 Transition in the Light-Driven Proton Pump Bacteriorhodopsin

Infrared Spectral Hole Burning of 1:1 Hydrogen-Bonded Complexes in Solution

A Theoretical Study of the Dynamics of Vibrational Wave Packets in the State Of Xe2

Temperature Effects Of Excitation Laser Pulses During Step-Scan FT-IR Measurements

Temporally Two-Dimensional Fifth-Order Raman Scattering on Intermolecular Vibrations in Cs2/Pentane Binary Mixtures

Spectral Hole Burning and Evidence for Vibrational Energy Migration of H-Bonded Molecules Observed With Transient Infrared Spectroscopy

Transient Absorption and Raman Studies on Exciplex Formation Dynamics of Photoexcited Cu(II)(TMpy-P4) With Synthetic Polynucleotide

Time-Resolved, Step-Scan Ftir Studies Of Excited States Of d⁶ Metal Polypyridine Complexes

Time-Resolved Step-Scan Ftir Investigations on the M₁→M₂ Transition in the Light-Driven Proton Pump Bacteriorhodopsin

A Theoretical Study of the Dynamics of Vibrational Wave Packets in the State Of Xe₂

Temporally Two-Dimensional Fifth-Order Raman Scattering on Intermolecular Vibrations in Cs₂/Pentane Binary Mixtures