The vinyloxonium cation, \documentclass{article}\pagestyle{empty}\begin{document}${\rm CH}_{\rm 2} = {\rm CH - }\mathop {\rm O}\limits^{\rm + } {\rm H}_{\rm 2}$\end{document}, a stable [C2H5O]+ species in the gas phase

The charge stripping mass spectra of [C₂H₅O]⁺ ions permit the clear identification of four distinct species: \documentclass{article}\pagestyle{empty}\begin{document}${\rm CH}_{\rm 3} - {\rm O - }\mathop {\rm C}\limits^{\rm + } {\rm H}_{\rm 2}$\end{document}, \documentclass{article}\pagestyle{empty}\begin{document}${\rm CH}_{\rm 3} - \mathop {\rm C}\limits^{\rm + } {\rm H - OH}$\end{document}, and \documentclass{article}\pagestyle{empty}\begin{document}${\rm CH}_{\rm 2} = {\rm CH - }\mathop {\rm O}\limits^{\rm + } {\rm H}_{\rm 2}$\end{document}. The latter, the vinyloxonium ion, has not been identified before. It is generated from ionized n-butanol and 1,3-propanediol. Its heat of formation is estimated to be 623±12 kJ mol^?1. The charge stripping method is more sensitive to these ion structures than conventional collisional activation, which focuses attention on singly charged fragment ions.     

Aluminum nanoparticles capped by polymerization of alkyl-substituted epoxides: ratio-dependent stability and particle size

We report here on the polymerization of epoxide monomers on incipient aluminum nanoparticle cores and the effects of changing the epoxide-capping precursor and the metallic monomer ratio on the resultant stability and particle size of passivated and capped aluminum nanoparticles. When altering the ratio of aluminum to cap monomer precursor, nanoparticles capped with epoxydodecane, epoxyhexane, and epoxyisobutane show a clear decreasing trend in stability with decreasing alkane substituent length. The nanoparticle core size was unaffected by cap ratio or composition. PXRD (powder X-ray diffraction) and DSC/TGA (differential scanning calorimetry/thermal gravimetric analysis) confirm the presence of successfully passivated face-centered cubic (fcc) aluminum nanoparticles. We also report preliminary results from ATR-FTIR (attenuated total reflectance-Fourier transform infrared), (13)C CPMAS (cross-polarization/magic-angle spinning), and (27)Al MAS solid-state NMR (nuclear magnetic resonance) measurements. The most stable aluminum nanoparticle-polyether core-shell nanoparticles are found at an Al:monomer mole ratio of 10:1 with an active Al(0) content of 94%.     

On the origin of fast forward moving ions generated from a repelled ion beam

Mass-selected positive ions having kilovolt translational energies can be reversed in direction by applying a large voltage to a collision chamber situated in the second field-free region of a reversed geometry instrument. It is shown that such repelled positive ions impinge on the earthed plate, situated in front of the chamber, leading to a variety of negative ions. The mass-to-charge ratios of these anions have been measured.     

Rekristallisation von Aluminium-Einkristallen

Zeitschrift für Physik A Hadrons and nuclei - Die Kristalle, welche sich durch B. R. nach einer relativ schwachen Deformation (10 bis 15 % Dehnung) aus einem Aluminiumeinkristall bilden,...     

The dissociation chemistry of ionized methyl carbamate and its isomers revisited: theory and experiment in concert

Early combined computational and experimental studies by J.K. Terlouw c.s. in Refs. 1-3 propose that low-energy methyl carbamate ions, NH(2)COOCH(3)(?+) (MC-1), rearrange into distonic ions NH(2)C(OH)OCH(2)(?+) and hydrogen-bridged radical cations [NH(2)C=O--H--OCH(2)](?+) (MC-5) en route to the observed losses of HCO(?) and CO. In this study, we report on the generation of ions MC-5 by decarbonylation of ionized methyl oxamate NH(2)COCOOCH(3)(?+). Theory and experiment agree that ion MC-5 is a key intermediate in the dissociation of low-energy ions MC-1. The subsequent HCO(?) loss, however, may not proceed via the route proposed in Ref. 2, but rather by an entirely different mechanism involving proton-transport catalysis (PTC) in ion MC-5. This view is further supported by the dissociation behaviour of the MC-5 isotopologue [ND(2)C=O--D--OCH(2)](?+), which is conveniently generated from the d(3)-labelled glycolamide ion DOCH(2)C(=O)ND(2)(?+).