Femtochemistry: Concepts and Applications

Zewail, Ahmed H.

doi:10.1002/9783527619436.ch2

Cited by 7 publications

(6 citation statements)

References 262 publications

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“…While molecular beam techniques [45] [51][52][53] and other single collision experiments using quantum state preparation and detection with lasers [54][55][56][57][58] have contributed enormously to our understanding of bimolecular gas phase reactions, perhaps the most dramatic developments in terms of time scales in reaction kinetics came from the development of short pulse lasers and their use in pump-probe experiments [42] [59][60][61], where the names of Rentzepis, Eisenthal and Kaiser may be named as representatives of the picosecond era following 1970 and Shank, Fleming, Hochstrasser, Zewail, Mathies, Laubereau, Zinth, Elsässer, and Keller for the femtosecond era following 1980 (see Table 1). …”

Section: Brief History Of Fundamental Ideas For Experiments In Chemicmentioning

confidence: 99%

Molecular Spectra, Reaction Dynamics, Symmetries and Life

Qüack¹

2003

Chimia

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We provide a short review of the work of the group for molecular kinetics and spectroscopy at the Laboratory for Physical Chemistry of ETH Zürich contributing to our understanding of the fundamental physical-chemical primary processes in chemical reactions. After a brief historical introduction, we present a selection of recent progress and thinking in three areas: 1. Experiments in high resolution molecular spectroscopy leading us from an elucidation and unraveling of molecular infrared spectra to the understanding of the molecular reaction dynamics and fast intramolecular processes from the nanosecond (1 ns = 10 -9 s) to the femtosecond (1 fs = 10 -15 s) and even sub-fs or attosecond (1 as = 10 -18 s) domain. 2. Theory of fundamental symmetries of physics and their violations in molecular spectra and dynamics of chiral molecules with a discussion of possible consequences for the role of chirality in the origin of life. 3. Speculative considerations on the relationship of spectra and dynamics of chiral molecules with the CPT theorem of physics and with the origin of matter and chiral life, and on the relationship of time reversal symmetry violation with the molecular origin of irreversibility and with the possible molecular origin of thought.

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Section: Brief History Of Fundamental Ideas For Experiments In Chemicmentioning

confidence: 99%

Molecular Spectra, Reaction Dynamics, Symmetries and Life

Qüack¹

2003

Chimia

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“…By choosing the time delay t and the frequency co of the probe pulse the time and the place of this process can be controlled, respectively [28]. In a typical experiment the wave packet dynamics is monitored by ionizing the molecule [29,30]. Since ionic potential curves for the CgA molecule are not known the probe signal is simulated in a simplified way.…”

Section: P(t) = (8)mentioning

confidence: 99%

From torsional spectra to Hamiltonians and dynamics: effects of coupled bright and dark states of 9-(N-carbazolyl)-anthracene

Manz

Proppe

Schmidt

1995

Z Phys D - Atoms, Molecules and Clusters

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Abstract. The torsional dynamics of the 9-(N-carbazolyl)-anthracene (C9A) molecule is investigated by means of time-independent (1) and time-dependent (2) quantummechanical simulations in adiabatic representation. The study includes effects of surface crossing of the bright St state with a dark state. (1) The intensity pattern of the So ~ St fluorescence excitation spectrum is used to fit an effective one-dimensional Hamiltonian with a single-minimum potential for the dark state together with diabatic couplings to the double well potential of the bright state.(2) Based on this Hamiltonian, first predictions for a pump-probe scheme are made. In the pump process the molecules are excited to the $1 state followed by competing torsions in the bright state and diabatic curve crossings to the dark state, depending on the pump frequency. Assuming the probe process to be an ionization from the bright state, the interfering effects of the dark state on the dynamics in the bright state can be monitored in a directly time-dependent way on a fs-ps time scale.

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“…1,2 Femtosecond excitation creates classicallike molecular wave packets, which are the basis of understanding the dynamics of chemical reactions: how they take place and how to govern them. [3][4][5][6] Laser pulses can be focused into extremely narrow spatial and temporal distributions, and thus multiphoton excitation is common and is an important subject for study.…”

Section: Introductionmentioning

confidence: 99%

Intrapulse Dynamical Effects in Multiphoton Processes: Theoretical Analysis

1998

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Stationary and nonstationary multilevel models are formulated to analyze ultrafast multiphoton processes with emphasis on electronic and nuclear coherence of a near-resonant intermediate state. By identifying and characterizing three intrapulse dynamical mechanisms (sequential-resonance, chirp-following, and time-delay), a clear physical picture is developed for understanding the subtle chirp dependence in intrapulse pumpprobe processes. The theoretical analysis in the paper provides not only a possible interpretation for a recent three-photon experiment but also a general theoretical framework for studying ultrafast multiphoton processes in atoms and molecules.

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Femtochemistry: Concepts and Applications

Cited by 7 publications

References 262 publications

Molecular Spectra, Reaction Dynamics, Symmetries and Life

Molecular Spectra, Reaction Dynamics, Symmetries and Life

From torsional spectra to Hamiltonians and dynamics: effects of coupled bright and dark states of 9-(N-carbazolyl)-anthracene

Intrapulse Dynamical Effects in Multiphoton Processes: Theoretical Analysis

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