Electron bombardment induced fragmentation of size selected neutral (D2O)
                n
               clusters

Buck, U.; Winter, M.

doi:10.1007/bf01445010

Cited by 26 publications

(21 citation statements)

References 48 publications

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“…At both ends of the investigated fragment masses the intensity is smaller. If we take into account the well known fragmentation [202] of the water clusters by electron impact ionization, where in addition to the protonation at least one monomer is lost for complexes larger than the dimer, we have the surprising result that fragments of the neutral precursor hexamer, and to a lesser extent also those of the pentamer and tetramer, are much more frequent than those of the dimer. This is in contrast to measurements of pure [193] and methanol doped [194] water clusters with sizes smaller than hni ¼ 20, which yielded the largest intensities for the smallest fragments.…”

Section: Photofragment Spectroscopymentioning

confidence: 91%

Solid water clusters in the size range of tens–thousands of H₂O: a combined computational/spectroscopic outlook

Buch

Bauerecker²,

Devlin³

et al. 2004

International Reviews in Physical Chemistry

224

294

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2004) Solid water clusters in the size range of tens-thousands of H 2 O: a combined computational/spectroscopic outlook, A joint computational and experimental effort was directed towards the understanding of large solid water clusters. The computations included structure optimizations and calculations of OH stretch spectra for select sizes in the range n ¼ 20-931. The measurements focused predominantly on OH stretch spectroscopy as a function of mean cluster size. FTIR spectra are discussed for the size range of tens to hundreds-of-thousands of molecules. Photofragment spectroscopy in molecular beams is shown to be a sensitive probe of the outer cluster surfaces. The crucial element of the different experimental approaches is the control and the estimation of the mean cluster sizes. The combined experimental and computational results are consistent with the physical picture of quasispherical nanocrystals with disordered reconstructed surface layers. The surface reconstruction can be viewed as the outcome of recombination of surface dangling atoms, to increase the number of hydrogen bonds. The hydrogen bonds within the mostly crystalline subsurface layer are stretched by the interaction with the disordered component. The emergence of the (strained) crystal core occurs at a size of a few hundred H 2 O. Smaller clusters are described as compactamorphous.

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Section: Photofragment Spectroscopymentioning

confidence: 91%

Solid water clusters in the size range of tens–thousands of H₂O: a combined computational/spectroscopic outlook

Buch

Bauerecker²,

Devlin³

et al. 2004

International Reviews in Physical Chemistry

224

294

View full text Add to dashboard Cite

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“…When methanol is introduced into the pickup chamber characteristic peaks at m/z = 31 amu (CH 2 18 From the earlier studies [52][53][54][55] of hydrogen bonded clusters, it was found that a fast proton transfer reaction follows the cluster ionization. Thus the major ionization channel results in the protonated fragments with the abstraction of one or more monomer units.…”

Section: B Poisson Distributionsmentioning

confidence: 99%

Cluster cross sections from pickup measurements: Are the established methods consistent?

Fedor

Poterya

Pysanenko

et al. 2011

The Journal of Chemical Physics

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Pickup of several molecules, H 2 O, HBr, and CH 3 OH, and Ar atoms on free Ar N clusters has been investigated in a molecular beam experiment. The pickup cross sections of the clusters with known mean sizes,N ≈ 150 and 260 were measured by two independent methods: (i) the cluster beam velocity decrease due to the momentum transfer of the picked up molecules to the clusters, and (ii) Poisson distribution of a selected cluster fragment ion as a function of the pickup pressure. In addition, the pickup cross sections were calculated using molecular dynamics and Monte Carlo simulations. The simulations support the results of the velocity measurements. On the other hand, the Poisson distributions yield significantly smaller cross sections, inconsistent with the known Ar N cluster sizes. These results are discussed in terms of: (i) an incomplete coagulation of guest molecules on the argon clusters when two or more molecules are picked up; and (ii) the fragmentation pattern of the embedded molecules and their clusters upon ionization on the Ar cluster. We conclude that the Poisson distribution method has to be cautiously examined, if conclusions should be drawn about the cluster cross section, or the mean cluster sizeN , and the number of picked up molecules.

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“…This means that the fragmentation of complexes formed in helium droplets is less pronounced than for similar systems of free clusters which usually lose two to three monomers. 34,35 Consequently, the spectrum recorded at the nominal trimer mass (CH 3 OH) 2 H ϩ in Fig. 3 should consist of contributions from the trimer and the tetramer.…”

Section: A Methanolmentioning

confidence: 99%

Vibrational spectroscopy of methanol and acetonitrile clusters in cold helium droplets

Behrens¹,

Fröchtenicht²,

Hartmann³

et al. 1999

The Journal of Chemical Physics

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Structure and hydration of the C4H4 •+ ion formed by electron impact ionization of acetylene clustersInfrared molecular beam depletion spectroscopy of small methanol and acetonitrile clusters embedded in large helium clusters has been studied in the spectral region of the CO stretch and the CH 3 rock mode from 1023 to 1059 cm Ϫ1 . The results are compared with the experimental spectra of the corresponding free clusters generated in adiabatic expansions and calculations based on density functional theory or empirical potential models. For methanol clusters, the two types of experimental results are the same for the dimer and trimer structure. Different isomers are found in cold helium for the tetramer and pentamer, namely a monomer and dimer attached to a cyclic trimer. For acetonitrile clusters in helium, aside from the dimer, different structures are observed. The spectra from the trimer to the hexamer are dominated by structures which contain the antiparallel dimer as building block with D 2d symmetry for the tetramer. They do not correspond to the minimum configurations observed for the free clusters. The fragmentation of the two cluster groups in helium droplets by electron impact ionization is discussed.

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Electron bombardment induced fragmentation of size selected neutral (D2O) n clusters

Cited by 26 publications

References 48 publications

Solid water clusters in the size range of tens–thousands of H₂O: a combined computational/spectroscopic outlook

Solid water clusters in the size range of tens–thousands of H₂O: a combined computational/spectroscopic outlook

Cluster cross sections from pickup measurements: Are the established methods consistent?

Vibrational spectroscopy of methanol and acetonitrile clusters in cold helium droplets

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Electron bombardment induced fragmentation of size selected neutral (D2O) n clusters

Cited by 26 publications

References 48 publications

Solid water clusters in the size range of tens–thousands of H2O: a combined computational/spectroscopic outlook

Solid water clusters in the size range of tens–thousands of H2O: a combined computational/spectroscopic outlook

Cluster cross sections from pickup measurements: Are the established methods consistent?

Vibrational spectroscopy of methanol and acetonitrile clusters in cold helium droplets

Contact Info

Product

Resources

About

Solid water clusters in the size range of tens–thousands of H₂O: a combined computational/spectroscopic outlook

Solid water clusters in the size range of tens–thousands of H₂O: a combined computational/spectroscopic outlook