Modeling of the Kinetics of Intramolecular Processes and Transient Spectra with Allowance for Nonradiative Transitions

Baranov, V.I.; Gribov, L.A.
July 2004
Journal of Applied Spectroscopy;Jul/Aug2004, Vol. 71 Issue 4, p453
Academic Journal
It has been shown that the kinetics of intramolecular processes and time‐resolved spectra with allowance for the quantum beats of the resonant states of isomers or isolated subsystems of levels of one isomeric form can be described with the use of a molecular model interpreting the effect of beats as a nonradiative transition. We have obtained an expression for the nonradiative transition probability, which is directly proportional to the beat frequency and depends oscillatorily on time, thus modeling the effect of beats. The parameter of the molecular system model is the beat frequency directly related to the parameter characterizing the intramolecular interisomeric interactions (the corresponding nondiagonal element of the energy matrix) rather than the value of the nonradiative transition probability. The character of the change in the level populations and, accordingly, in the band intensities in the spectra in the proposed model is in good agreement with the experiment, including the fine structure of the time dependences — oscillations of the line intensities. In analyzing the temporal experiment with a high resolution, it is necessary to take into account the instrument function leading to quantitative and qualitative changes in the time dependences. The traditional model of nonradiative transitions with a constant probability value has a very limited range of applicability — very high beat frequencies compared to the probability of optical transitions.


Related Articles

  • Chemical timing 4. The rovibronic level structure associated with intramolecular vibrational redistribution in S1 p-difluorobenzene. Dolson, D. A.; Holtzclaw, K. W.; Moss, D. B.; Parmenter, C. S. // Journal of Chemical Physics;2/1/1986, Vol. 84 Issue 3, p1119 

    The method of chemical timing for obtaining picosecond time-resolved fluorescence spectra has been applied to the measurement of intramolecular vibrational redistribution (IVR) in S1 p-difluorobenzene. In this report, a more detailed examination of the spectroscopy of some vibrationally mixed...

  • Signs of structural changes in molecules in IR spectra with pulsed heating. Baranov, V.; Gribov, L. // Journal of Applied Spectroscopy;Nov2007, Vol. 74 Issue 6, p817 

    We have shown that in slow thermal reactions of complex molecules, effects of nonradiative transitions due to quantum beats between resonant states of the combining molecular structures can be observed in conventional (without high time resolution) IR absorption spectra, as oscillations in the...

  • Applications of a time correlation function theory for the fifth-order Raman response function I: Atomic liquids. DeVane, Russell; Ridley, Christina; Space, Brian; Keyes, T. // Journal of Chemical Physics;11/15/2005, Vol. 123 Issue 19, p194507 

    Multidimensional spectroscopy has the ability to provide great insight into the complex dynamics and time-resolved structure of liquids. Theoretically describing these experiments requires calculating the nonlinear-response function, which is a combination of quantum-mechanical time correlation...

  • Time-resolved photoluminescence of red mercuric iodide. Wen, X. M.; Ohno, N. // Journal of Applied Physics;4/1/2002, Vol. 91 Issue 7, p4095 

    Time-resolved photoluminescence (TRPL) spectrum of red mercuric iodide single crystal for two kinds of different grown methods was measured and compared at low temperatures. The different spectral structures were found for the different grown crystals. At the band-gap region two kinds of...

  • Time-Resolved Spectroscopy Comes of Age. Ouellette, Jennifer // Industrial Physicist;Feb/Mar2004, Vol. 10 Issue 1, p18 

    Discusses the workability of the newly developed time-resolved spectroscopy technique. Capacity to measure temporal dynamics and the kinetics of photophysical processes; Utilization of camera or a pulsed beam of light as a detector; Application of pump-robe spectroscopy.

  • Ultrafast soft x-ray absorption spectroscopy with sub-20-fs resolution. Seres, Enikoe; Spielmann, Christian // Applied Physics Letters;9/17/2007, Vol. 91 Issue 12, p121919 

    The most challenging application of time-resolved spectroscopy is to watch the motion of atoms directly. In the current experiment, we were able to follow the displacement of atoms in silicon after excitation with an intense near infrared femtosecond laser pulse with time-resolved x-ray...

  • Dynamics of radiationless transitions in large molecules: 1. Absorption spectra of adjoin reservoir states. Benderskii, V. // High Energy Chemistry;Nov2011, Vol. 45 Issue 6, p447 

    The dynamics of radiationless transitions in large molecules interacting with the surroundings is determined by the dense discrete spectrum of final states { R}, close in energy to the initial state s, and by the sets of SR-coupling matrix elements and the decay rate constants of S and { R}. It...

  • Classical model of femtosecond time-resolved absorption spectra of dissociating molecules. Walkup, R. E.; Misewich, J. A.; Glownia, J. H.; Sorokin, P. P. // Journal of Chemical Physics;3/1/1991, Vol. 94 Issue 5, p3389 

    We present a simple classical model for understanding time-resolved absorption spectra of molecules that are in the process of dissociating. The model applies to absorption spectra that are obtained by measuring the spectral power density of an ultrafast, continuum probe pulse after transmission...

  • Systematic features of the energy dependence of radiationless processes in large molecules: The substituted naphthalenes. Jacobson, Benjamin A.; Guest, Joyce A.; Novak, Frank A.; Rice, Stuart A. // Journal of Chemical Physics;7/1/1987, Vol. 87 Issue 1, p269 

    This work examines, both experimentally and theoretically, nonradiative decay processes in a series of substituted naphthalenes. We report single vibronic level fluorescence lifetimes and fluorescence excitation spectra of jet-cooled 2-chloronaphthalene, 1- and 2-fluoronaphthalene and 1- and...


Read the Article


Sorry, but this item is not currently available from your library.

Try another library?
Sign out of this library

Other Topics