Download or read book Photodissociation Spectroscopy and Dynamics of Free Radicals Clusters and Ions written by and published by . This book was released on 1999 with total page 169 pages. Available in PDF, EPUB and Kindle. Book excerpt: The photodissociation spectroscopy and dynamics of free radicals and ions is studied to characterize the dissociative electronic states in these species. To accomplish this, a special method of radical production, based on the photodetachment of the corresponding negative ion, has been combined with the technique of fast beam photofragment translational spectroscopy. The photofragment yield as a function of photon energy is obtained, mapping out the dissociative and predissociative electronic states. Branching ratios to various product channels, the translational energy distributions of the fragments, and bond dissociation energies are then determined at selected photon energies. The detailed picture of photodissociation dynamics is provided with the aid of ab initio calculations and a statistical model to interpret the observed data. Important reaction intermediates in combustion reactions have been studied: CCO, C2H5O, and linear C{sub n} (n = 4--6).

Download or read book Photodissociation Spectroscopy and Dynamics of Free Radicals Clusters and Ions written by Hyeon Choi and published by . This book was released on 1999 with total page 340 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Spectroscopy and dynamics of radicals clusters and ions written by [Anonymus AC05198838] and published by . This book was released on 2005 with total page 364 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Photodissociation Dynamics and Spectroscopy of Free Radical Combustion Intermediates written by and published by . This book was released on 1996 with total page 422 pages. Available in PDF, EPUB and Kindle. Book excerpt: The photodissociation spectroscopy and dynamics of free radicals is studied by the technique of fast beam photofragment translational spectroscopy. Photodetachment of internally cold, mass-selected negative ions produces a clean source of radicals, which are subsequently dissociated and detected. The photofragment yield as a function of photon energy is obtained, mapping out the dissociative and predissociative electronic states of the radical. In addition, the photodissociation dynamics, product branching ratios, and bond energies are probed at fixed photon energies by measuring the translational energy, P(E{sub T}), and angular distribution of the recoiling fragments using a time- and position-sensitive detector. Ab initio calculations are combined with dynamical and statistical models to interpret the observed data. The photodissociation of three prototypical hydrocarbon combustion intermediates forms the core of this work.

Download or read book Photodissociation Dynamics and Spectroscopy of Free Radical Combustion Intermediates written by David Lewis Osborn and published by . This book was released on 1996 with total page 842 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book The Energetics and Dynamics of Free Radicals Ions and Clusters written by and published by . This book was released on 1993 with total page 6 pages. Available in PDF, EPUB and Kindle. Book excerpt: Structure and energetics of free radicals, ions, and clusters are being investigated by photoelectron photoion coincidence and analyzed using ab initio molecular orbital and statistical theory (RRKM). Molecules or free radicals are prepared in a molecular beam. Translational temperature is found from measured time of flight peakwidth; the vibrational temperature, from shift in dissociation onset. Free radicals are produced by pyrolysis in the nozzle; their subsequent cooling is demonstrated. Ion dissociation rates in the range from 10[sup 4] to 10[sup 7] s[sup [minus]1] are measured from the asymmetric TOF distribution; this method was used to measure the dissociation rates of cold and warm butene ions. 2 figs.

Download or read book Photodissociation Dynamics of Free radicals written by Eric Michael Ross and published by . This book was released on 1995 with total page 202 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Studies of Transition States Clusters and Radicals by Negative Ion Photodetachment and Photodissociation written by and published by . This book was released on 2006 with total page 7 pages. Available in PDF, EPUB and Kindle. Book excerpt: Our AFOSR-supported research during the last three years focused on several experimental programs at the interface of ion spectroscopy and molecular reaction dynamics. We have developed a new method for high resolution photodetachment spectroscopy of negative ions based on photoelectron imaging (SEVI, or Slow photoElectron Velocity-map Imaging) and applied it to simple test systems as well as a pre-reactive van der Waals complex. We have measured photoelectron spectra of solvated transition state precursor anions, and used the vibrational structure in these spectra to infer to effect of various solvents on the strong hydrogen bond in the anion core. This work led to a series of experiments in which we measured the infrared spectra of several strongly hydrogen-bonded anions and the protonated water dimer H5O2+. These experiments were performed on the Free Electron Laser for Infrared experiments (FELIX) which produces high power, tunable infrared pulses over a broad spectral range, enabling the first measurements of the low (

Download or read book State selected Study of Ion molecule Reaction Dynamics Photodissociation Dynamics and Free Radical Studies Using Synchrotron Radiation written by Tao Zhang and published by . This book was released on 2003 with total page 406 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Understanding the Photodissociation Dynamics of Molecular Cluster Ions written by Nicole D. Delaney and published by . This book was released on 1999 with total page 316 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Photodissociation and Reaction Dynamics of Small Molecules and Free Radicals Via High n Rydberg Hydrogen Atom Time of Flight Spectroscopy written by Kesheng Xu and published by . This book was released on 2001 with total page 390 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book The Energetics and Dynamics of Free Radicals Ions and Clusters Progress Report written by and published by . This book was released on 1994 with total page 12 pages. Available in PDF, EPUB and Kindle. Book excerpt: The structure and energetics of free radicals, ions, and clusters have been investigated by photoelectron photoion coincidence (PEPICO) and analyzed with the aid of ab initio molecular orbital and statistical theory (RRKM) calculations. The two major themes are the quantitative analysis of unimolecular reactions with no adjustable parameters, and the study of cluster ion dissociation processes. Molecules (or free radicals) were prepared in a molecular beam so that they are translationally and vibrationally cold. The translational temperature was calculated from the measured time of flight (TOF) peak width, while the vibrational temperature was determined from the shift in the dissociation onset. Free radicals are produced by pyrolysis in the nozzle, and subsequent cooling of the free radicals is demonstrated. Ion dissociation rates in the range from 104 to 107 sec−1 are measured from the asymmetric TOF distribution. This method was used to measure the dissociation rates of a number of cold and warm ions, among them HCl (DCl) loss from C2H5Cl (C2D5Cl), a reaction that proceeds via tunneling. The analysis of the butene ion dissociation provided information about the role of angular momentum in dissociation reactions. This dissociative ionization of ethylene clusters demonstrated that ethylene dimer ions rearranged to butene ions prior to dissociation. Finally, a new value for the t-butyl ion heat of formation, which corrects a 15 kJ/mol error in the previous value, was obtained from the 0 K breakdown diagram of t-butyl iodide.

Download or read book Spectroscopy and Decay Dynamics of Some Halogenated Free Radicals and Ions written by Jeremy Charles Creasey and published by . This book was released on 1991 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Coincidence and Noncoincidence Studies of the Photodissociation Dynamics of Free Radicals written by Ann Elise Faulhaber and published by . This book was released on 2005 with total page 238 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Photoisomerization and Photodissociation Dynamics of Reactive Free Radicals written by and published by . This book was released on 2000 with total page 198 pages. Available in PDF, EPUB and Kindle. Book excerpt: The photofragmentation pathways of chemically reactive free radicals have been examined using the technique of fast beam photofragment translational spectroscopy. Measurements of the photodissociation cross-sections, product branching ratios, product state energy distributions, and angular distributions provide insight into the excited state potential energy surfaces and nonadiabatic processes involved in the dissociation mechanisms. Photodissociation spectroscopy and dynamics of the predissociative {tilde A}2A1 and {tilde B}2A2 states of CH3S have been investigated. At all photon energies, CH3 + S(3P{sub j}), was the main reaction channel. The translational energy distributions reveal resolved structure corresponding to vibrational excitation of the CH3 umbrella mode and the S(3P{sub j}) fine-structure distribution from which the nature of the coupled repulsive surfaces is inferred. Dissociation rates are deduced from the photofragment angular distributions, which depend intimately on the degree of vibrational excitation in the C-S stretch. Nitrogen combustion radicals, NCN, CNN and HNCN have also been studied. For all three radicals, the elimination of molecular nitrogen is the primary reaction channel. Excitation to linear excited triplet and singlet electronic states of the NCN radical generates resolved vibrational structure of the N2 photofragment. The relatively low fragment rotational excitation suggests dissociation via a symmetric C{sub 2V} transition state. Resolved vibrational structure of the N2 photofragment is also observed in the photodissociation of the HNCN radical. The fragment vibrational and rotational distributions broaden with increased excitation energy. Simple dissociation models suggest that the HNCN radical isomerizes to a cyclic intermediate (c-HCNN) which then dissociates via a tight cyclic transition state. In contrast to the radicals mentioned above, resolved vibrational structure was not observed for the ICNN radical due to extensive fragment rotational excitation, suggesting that intermediate bent states are strongly coupled along the dissociation pathway. The measurements performed in this Thesis have additionally refined the heats of formation and bond dissociation energies of these radicals and have unambiguously confirmed and added to the known electronic spectroscopy.

Download or read book UV photodissociation Dynamics of Small Molecules and Free Radicals Studied by High n Rydberg H Atom Time of Flight Spectroscopy written by Gabriel Alejandro Amaral and published by . This book was released on 2001 with total page 406 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book The Photodissociation Dynamics of Small Ion Clusters written by HyunSook Kim and published by . This book was released on 1988 with total page 396 pages. Available in PDF, EPUB and Kindle. Book excerpt: