Vibrational Relaxation and Photodissociation Dynamics in Solution PDF Download

Author: Christopher George Elles
Publisher:
ISBN:
Category :
Languages : en
Pages : 256

View

Book Description

Author:
Publisher:
ISBN:
Category :
Languages : en
Pages : 10

View

Book Description
These experiments use ultrafast laser spectroscopy to study reaction and photodissociation dynamics in solution, probing both photodissociation and intramolecular energy transfer. They have observed the photodissociation dynamics of methylhypochlorite (CH3OCl) in different solvents by monitoring the disappearance of the Cl atom and have compared the flow of energy in vibrationally excited methyl iodide (CH3l) in solution and in the gas phase. This second experiment is one of the few direct comparisons of intramolecular vibrational energy flow in a solvated molecule with that in the same molecule isolated in a gas. Because of the importance of vibrational relaxation of molecules after photoisomerization, the other goal has been to probe the vibrational energy flow in both cis and trans-stilbene, a prototypical molecule for cis-trans isomerization.

Author:
Publisher:
ISBN:
Category :
Languages : en
Pages : 126

View

Book Description
Photodissociation of M(CO)6 (M=Cr, Mo, W) and the formation of solvated M(CO)5·S complex was studied in cyclohexane; rate-limiting step is vibrational energy relaxation from the new bond to the solvent. For both M=Cr and Mo, the primary relaxation occurs in 18 ps; for Cr, there is an additional vibrational relaxation (150 ps time scale) of a CO group poorly coupled to other modes. Relaxation of M=W occurs in 42 ps; several possible mechanisms for the longer cooling are discussed. Vibrational relaxation is also investigated for I2− and IBr− in nonpolar and slightly polar solvents. Attempts were made to discover the mechanism for the fast energy transfer in nonpolar solvent. The longer time scale dynamics of I3− and IBr2− were also studied; both formed a metastable complex following photodissociation and 90-95% return to ground state in 100 ps, implying a barrier to recombination of 4.3 kcal/mol and a barrier to escape of e".5 kcal/mol. The more complex photochemistry of M3(CO)12 (M=Fe, Ru) is also investigated, using visible and ultraviolet radiations, dissociation, geminate recombination, vibrational relaxation, and bridging structures and their reactions were studied. Attempts were made to extend ultrafast spectroscopy into the mid-infrared, but signal-to-noise was poor.

Author: M. Jocelyn Cox
Publisher:
ISBN:
Category :
Languages : en
Pages : 342

View

Book Description

Author: Maximilian Morrison Heckscher
Publisher:
ISBN:
Category :
Languages : en
Pages : 186

View

Book Description

Author: Jason Christopher King
Publisher:
ISBN:
Category :
Languages : en
Pages : 258

View

Book Description

Author: Jacqueline Leigh Scott
Publisher:
ISBN:
Category :
Languages : en
Pages : 544

View

Book Description

Author: Phillippe Bado
Publisher:
ISBN:
Category : Iodine
Languages : en
Pages : 266

View

Book Description

Author: Gianluca Levi
Publisher: Springer Nature
ISBN: 3030286118
Category : Science
Languages : en
Pages : 208

View

Book Description
This book explores novel computational strategies for simulating excess energy dissipation alongside transient structural changes in photoexcited molecules, and accompanying solvent rearrangements. It also demonstrates in detail the synergy between theoretical modelling and ultrafast experiments in unravelling various aspects of the reaction dynamics of solvated photocatalytic metal complexes. Transition metal complexes play an important role as photocatalysts in solar energy conversion, and the rational design of metal-based photocatalytic systems with improved efficiency hinges on the fundamental understanding of the mechanisms behind light-induced chemical reactions in solution. Theory and atomistic modelling hold the key to uncovering these ultrafast processes. Linking atomistic simulations and modern X-ray scattering experiments with femtosecond time resolution, the book highlights previously unexplored dynamical changes in molecules, and discusses the development of theoretical and computational frameworks capable of interpreting the underlying ultrafast phenomena.

Author: Reinhard Schinke
Publisher: Cambridge University Press
ISBN: 9780521484145
Category : Science
Languages : en
Pages : 446

View

Book Description
Photodissociation induced by the absorption of single photons permits the detailed study of molecular dynamics such as the breaking of bonds, internal energy transfer and radiationless transitions. The availability of powerful lasers operating over a wide frequency range has stimulated rapid development of new experimental techniques which make it possible to analyse photodissociation processes in unprecedented detail. This text elucidates the achievements in calculating photodissociation cross-sections and fragment state distributions from first principles, starting from multi-dimensional potential energy surfaces and the Schrödinger equation of nuclear motion. Following an extended introduction in which the various types of observables are outlined, the book summarises the basic theoretical tools, namely the time-independent and the time-dependent quantum mechanical approaches as well as the classical picture of photodissociation. The discussions of absorption spectra, diffuse vibrational structures, the vibrational and rotational state distributions of the photofragments form the core of the book. More specific topics such as the dissociation of vibrationally excited molecules, emission during dissociation, or nonadiabatic effects are also discussed. It will be of interest to graduate students and senior scientists working in molecular physics, spectroscopy, molecular collisions and molecular kinetics.