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Showing 1 to 20 of 23 for “"predissociation"”.
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Production and vibrational predissociation spectra of solvated alkali ions
… ions have been collected by the vibrational predissociation method using a modulated C.W. CO$\sb2$ laser.
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Vibrational predissociation spectroscopy of hydrogen-bonded complexes in the 10 micron region
Vibrational predissociation spectroscopy of isotopomers of (CH$\sb3$OH)$\sb2$ and Ar(CH$\sb3$OH) were recorded in the 10 micron region, where the C-O stretching transition is located. Using the beam depletion technique, spectra were recorded for (CH$\sb3$OH)$\sb2$, …
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Rydberg spectroscopy of calcium monofluoride
… its D² [sigma]⁺ intermediate state. Since the predissociation limit of CaF lies only 2,800 cm⁻¹ (n* [approximately] 6.3) below its first ionization potential, it had long been believed that the predissociation of CaF has little effect on the spectra. It is surprising that our observations show …
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Spectra and dynamics of calcium monochloride
… of CaCl is challenging because of the onset of predissociation at n* [approx.] 3. The reduction in ionization quantum yield associated with the predissociation greatly reduces our ability to record Rydberg state spectra, but provides opportunities to model the predissociation processes with the …
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The spectroscopy of bound and predissociating Rydberg states of NO in external electric fields
… of the A2Σ+ state. The N (2D) atoms produced by predissociation are measured by (2 + 1) resonance-enhanced multiphoton ionization. The zero field and predissociation spectra are analysed using a matrix diagonalisation method. In Chapter 5, initial progress on simulating the spectra is presented. …
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Inter-Rydberg excitation spectroscopy of krypton dimers
… were then probed with a dye laser, and the predissociation of the upper states of these transitions produced atomic fluorescence. Suppressions in the fluorescence, which were correlated with atomic transitions, demonstrate that the atomic 5p (3/2) $\sb1$ state is the primary product of the …
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Spectroscopy of even-parity states of molecular hydrogen
… is the first time that the autoionization and predissociation yields of individual s and d Rydberg states are detected separately. This is accomplished by first exciting the molecular hydrogen to the B(v=O,J} state by tunable narrow band VUV radiation. This prepares the molecular hydrogen for …
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Internal and External Vibrations of Weakly Bound Molecular Complexes: Infrared Spectroscopy and Vibrational Analysis
Infrared vibrational predissociation spectroscopy has been used to study the internal (intramolecular) and external (intermolecular) vibrations of weakly bound molecular complexes in a molecular beam apparatus. The apparatus features a continuous supersonic expansion source and mass selective …
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Effects of Solar Soft X-rays on Earth's Atmosphere
… cross-sections of its excitation states (using predissociation factors) and dissociative ionization channels. Predissociation is the transition without emission of radi- ation from a stable excited state to an unstable excited state of a molecule that leads to dissociation. Unfortunately, the …
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Infrared spectroscopy and Monte Carlo simulations of gas phase, solvated alkali ions
… cluster ions are mass-selected for vibrational predissociation spectroscopy. The spectra are collected using a line-tunable cw-CO$\sb2$ laser.
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The investigation of infrared absorption intensities in hydrogen-bonded complexes
… the use of infrared spectroscopy. Vibrational predissociation of strongly hydrogen bonded dimers has been performed using the molecular beam depletion technique. An investigation of the O-H stretches in (CH$\sb3$OH)$\sb2$ under low resolution (OPO linewidth = 4 cm$\sp{-1}$) yielded uniquely …
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Radiative and predissociative lifetimes of the A²Σ⁺ state of OH
… and on the unresolved levels of v =2. A predissociation, previously predicted from relative intensity measurements, resulting from a curve crossing by the repulsive 4 Σˉ state, was observed for the rotational states above K = 23 of v = 0, for those above K = 14 of v = 1, and for all those …
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Excited State Spectroscopy of Diatomic Argon
… are not observed, indicating that the predissociation lifetimes of these upper levels fall rapidly for $\rm v\sp\prime>1.$ Data presented lead to rotational energies and molecular constants for the $a\ \sp3\Sigma\sbsp{u}{+}$ and $7p\sigma\ \sp3\Sigma\sbsp{g}{+}$ states, including the …
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Infrared spectroscopy of ion-hydrocarbon clusters
… this, a combination of gas phase infrared predissociation spectroscopy (IRPD) and tandem mass spectrometry is utilized. The solvation of alkali metal ions by methane is discussed first, beginning with the effects of multiple argon atoms on Li+•••CH4 dimer clusters followed by a study of …
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Quantum State Singlet-Triplet Character Control in 7Li2
… in cold molecule formation and control of predissociation rates, and may also provide insight into the role that valence electron spin polarization plays in reactive collisions.
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The investigation of solvent shell structure and reactivity in solvated metal ion clusters
… molecular beam mass-spectrometry, vibrational predissociation spectroscopy and Monte Carlo simulation. Cluster ions of the form M$\sp+$(S)$\sb{\rm N}$, M = Cs, Na and S = CH$\sb3$OH, NH$\sb3$, CH$\sb3$NH$\sb2$, (CH$\sb3)\sb2$CO and (CH$\sb3)\sb2$SO were prepared in the source chamber of …
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Infrared spectroscopy of cluster ions: High energy conformer trapping and multiple photon absorption
Infrared predissociation (IRPD) spectra of several cluster ions are presented, resulting in the emergence of two major themes. Trapped, high energy conformers are observed in argon tagged clusters. In non-argon tagged hydrated alkali metal ion clusters, multiple photon absorption processes can …
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The photodissociation of small Aldehydes: a refined understanding of prototypical dynamical systems
… on a timescale shorter than the vibrational predissociation of HCO. The quantum yield of the triple fragmentation channel grows exponentially above threshold and is well modelled by a modified double phase space theory (PST) model. The (2+1) REMPI spectrum of H2 via the E,F state was …
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Exploring the effect of a potential barrier on the molecular rotation-vibration structure
… fluorescence (LIF) scheme (due to acetylene predissociation), combined with a partial breakdown of the polyad fit model, has made it increasingly difficult to understand the HCCH A-state level-structure near the top of the cis-trans isomerization barrier. Two new sensitive and convenient …
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