ISSN:0005-9021    

DOI:10.1002/bbpc.19840880302

出版商:Wiley‐VCH Verlag GmbH&Co. KGaA    

年代:1984

数据来源: WILEY

摘要:

AbstractSome features of the structure, the dynamics of nuclear motion, the nature of electronic states, excited‐state energetics and relaxation phenomena in “isolated” nonmetallic clusters are reviewed, with an emphasis on the interrelationship between the characteristics of molecular and condensed phase sy

ISSN:0005-9021    

DOI:10.1002/bbpc.19840880303

出版商:Wiley‐VCH Verlag GmbH&Co. KGaA    

年代:1984

数据来源: WILEY

摘要:

AbstractThis review reports on the microcluster research at Konstanz University. Metallic and ionic microclusters are produced by an inert gas condensation technique, while clusters from different gases are obtained by adiabatic expansion. An electronic time of flight‐mass‐spectrometer is used for cluster detection. Fragmentation processes, pronounced intensity distributions and the disintegration of multiple charged microclusters are discussed. An example of intramolecular reaction in organic clusters is gi

ISSN:0005-9021    

DOI:10.1002/bbpc.19840880304

出版商:Wiley‐VCH Verlag GmbH&Co. KGaA    

年代:1984

数据来源: WILEY

摘要:

AbstractMass spectra of argon clusters from a supersonic expansion measured by electron impact or photo ionization are similar to those obtained by Penning ionization. Associative ionization of clusters is not observed. This allows a determination of the condensed fraction in the beam. The mean cluster size is compared to data of other authors and heavy fragmentation of the clusters upon ionization is found. The ionized atom in a cluster will react very rapidly to a dimer ion, whose large binding energy of about 1 eV will lead to cluster fragmentation. A time table of events happening in a rare gas cluster after ionization is conjectured.

ISSN:0005-9021    

DOI:10.1002/bbpc.19840880305

出版商:Wiley‐VCH Verlag GmbH&Co. KGaA    

年代:1984

数据来源: WILEY

摘要:

AbstractClusters of Ar, CH4and N2are produced in a free jet expansion and studied by electron diffraction. Large clusters comprising several thousand molecules have a crystalline structure. Simple models have been constructed on the basis of the same fcc structure, with a particular attention paid to molecular motions in the case of N2. Small clusters with a few ten molecules have an amorphous structure, namely the polyicosahedral structure which has been established previously for small Ar clusters.

ISSN:0005-9021    

DOI:10.1002/bbpc.19840880306

出版商:Wiley‐VCH Verlag GmbH&Co. KGaA    

年代:1984

数据来源: WILEY

摘要:

AbstractHeterodimers of fluorobenzene (FB) with 1,4‐dioxane and methanol were synthesized in a seeded supersonic beam and studied by resonant two‐photon ionization combined with TOF mass spectrometry. The electronic spectra near the origin of the S1(π π*)← S0transition of FB revealed solvent induced shifts and spectral features due to the excitation of van der Waals modes. In addition, strong dynamic behaviour of the photo‐ionized dimers could be

ISSN:0005-9021    

DOI:10.1002/bbpc.19840880307

出版商:Wiley‐VCH Verlag GmbH&Co. KGaA    

年代:1984

数据来源: WILEY

摘要:

AbstractClusters of ammonia, formed by adiabatic expansion, were subjected to analysis in a time‐of‐flight mass spectrometer following multiphoton ionization. All cluster ions had the composition (NH3)n· H+(withnranging up to approximately 65) and none corresponding to (NH3)n·+were detected with the exception ofn= 1. An unusually stable species (NH4+)(NH3)4was produced under all expansion and ionizing conditions investigated; it is attributed to an especially stable ion structure. Well resolved rotational structure for the β and c̄ states of a cold monomer beam were obtained and rotational assignments are presented for the c̄' band. A search for resonances in the ammonia clusters failed to reveal any well resolved structure, although isotope shifts in the monomer spectra were found through use of deuterium subs

ISSN:0005-9021    

DOI:10.1002/bbpc.19840880308

出版商:Wiley‐VCH Verlag GmbH&Co. KGaA    

年代:1984

数据来源: WILEY

摘要:

AbstractMethods for the production of small molecules Mnwith 2

ISSN:0005-9021    

DOI:10.1002/bbpc.19840880309

出版商:Wiley‐VCH Verlag GmbH&Co. KGaA    

年代:1984

数据来源: WILEY

摘要:

AbstractRecent developments in laser and molecular beam technology have now made it possible to produce supersonic beams of metal clusters of virtually any metal in the periodic table. The availability of these clusters for study in the gas phase provides an opportunity to investigate in detail the physics and chemistry of economically important and scientifically interesting metal cluster species. Initially, studies have involved the investigation of the metal‐metal bond in transition metal dimers, including Cr2, Mo2, V2, and Ni2through resonant twophoton ionization spectroscopy. These studies have demonstrated the importance of 3d (and 4d) electrons in the metal‐metal bond in Cr2, Mo2, and V2. A comparison of V2and Cr2illustrates the importance of the 3d contraction with increasing nuclear change, and this is found to be of central concern in Ni2, where no 3d contribution to the chemical bond is found. Finally, Cu3is investigated, providing the first gas‐phase spectrum of a triatomic transition metal cluster. Electronically, Cu3is analogous to Na3and other alkali trimers, so it is not surprising that the observed spectrum is best explained as arising from a Jahn‐Teller distorted2E' state (in D3hsymmetry), as has been calculated for Li3. The observed transition in Cu3is assigned to be2E”←2E', with both upper and lower states undergoing Jahn‐Telle

ISSN:0005-9021    

DOI:10.1002/bbpc.19840880310

出版商:Wiley‐VCH Verlag GmbH&Co. KGaA    

年代:1984

数据来源: WILEY

摘要:

AbstractThe investigation of the small clusters of metallic and nonmetallic elements shows that some clusters have some features common with the crystals (cluster bond lengths and cluster bond angles) and simultaneously other stable cluster forms exhibit very specific properties (for example, the planarity of Ia, IIIa, IVa‐tetramers, and Li6, Li7clusters with pentagonal symmetries). The cluster stability and geometry can be generally well explained from the electronic properties of constituent atoms. Studies of the interactions of clusters with atoms and small molecules yield results which are interesting for the theory of chemisorption (for example, the donation, back‐donation picture of the CO‐metal interaction) and for the understanding of the electronic structure of organometallic comp

ISSN:0005-9021    

DOI:10.1002/bbpc.19840880311

出版商:Wiley‐VCH Verlag GmbH&Co. KGaA    

年代:1984

数据来源: WILEY