Physics and Chemistry of Finite Systems: From Clusters to Crystals, 1992
Neutral rare gas clusters have one of the simplest kind of chemical binding. Every atom is bound ... more Neutral rare gas clusters have one of the simplest kind of chemical binding. Every atom is bound to its neighbours by the same kind of weak undirectional van der Waals force. The first electronic excitation is far in the vacuum UV region [1]. An electron is removed from a strongly antibonding orbital if the duster is ionised. Consequently the bonding becomes much stronger around the charge, and differs in character, direction and strength. The optical absorption shifts to the visible. The absorption is due to the charge localisation on a molecular chromophore. It was originally deduced from energetic considerations and condensed state data [2], that the positive charge in a rare gas cluster ion localizes after about a picosecond on a dimer ion, e.g. Ar 2 + . An argon cluster ion Ar n + would thus have a Ar 2 + Ar n−2. structure. Later experimental [3, 4, 5, 6, 7] and theoretical [8, 9, 10] results pointed to charge localization on a larger unit: Ar n + with n = 3 or 4. This view is not universally shared: Stace and coworkers [11] deduce from their data that the charge does localize on a dimer ion. However Deluca and Johnson [12] and Bowers et al.[13] favour an Ar 2 + − Ar double minimum potential, a notion which is contested by Gadea and Malrieu [14]. Carnovale et al. [15] deduce from their photoelectron spectra n = 3, 7, or 13, depending on cluster size.
Journal of the Chemical Society, Faraday Transactions, 1990
The following properties have been measured for mercury clusters: (1) ionisation potentials of Hg... more The following properties have been measured for mercury clusters: (1) ionisation potentials of Hg, by electron-impact ionisation, (2) dissociation energies of Hg; , and (3) mass spectra for negatively charged mercury cluster ions (n > 3). Cohesive energies for neutral and ...
Received 8 July l991) Photoabsorption cross sections for Ar, +, 3~n~80, and Xe"+, 3~n~30, cluster... more Received 8 July l991) Photoabsorption cross sections for Ar, +, 3~n~80, and Xe"+, 3~n~30, clusters have been measured. A single absorption maximum in the visible is observed for Ar", whose redshift with growing n is interpreted as a delocalization of the charge from a trimer to a tetramer ion. For Xe3+, two maxima, and for Xe, +, n~5, three maxima are observed. For n~5 the positive charge can localize onto either a trimer or a tetramer ion core, both surrounded by neutral atoms. The transition between the two isomers is faster than 10 ns.
Physics and Chemistry of Finite Systems: From Clusters to Crystals, 1992
Neutral rare gas clusters have one of the simplest kind of chemical binding. Every atom is bound ... more Neutral rare gas clusters have one of the simplest kind of chemical binding. Every atom is bound to its neighbours by the same kind of weak undirectional van der Waals force. The first electronic excitation is far in the vacuum UV region [1]. An electron is removed from a strongly antibonding orbital if the duster is ionised. Consequently the bonding becomes much stronger around the charge, and differs in character, direction and strength. The optical absorption shifts to the visible. The absorption is due to the charge localisation on a molecular chromophore. It was originally deduced from energetic considerations and condensed state data [2], that the positive charge in a rare gas cluster ion localizes after about a picosecond on a dimer ion, e.g. Ar 2 + . An argon cluster ion Ar n + would thus have a Ar 2 + Ar n−2. structure. Later experimental [3, 4, 5, 6, 7] and theoretical [8, 9, 10] results pointed to charge localization on a larger unit: Ar n + with n = 3 or 4. This view is not universally shared: Stace and coworkers [11] deduce from their data that the charge does localize on a dimer ion. However Deluca and Johnson [12] and Bowers et al.[13] favour an Ar 2 + − Ar double minimum potential, a notion which is contested by Gadea and Malrieu [14]. Carnovale et al. [15] deduce from their photoelectron spectra n = 3, 7, or 13, depending on cluster size.
Journal of the Chemical Society, Faraday Transactions, 1990
The following properties have been measured for mercury clusters: (1) ionisation potentials of Hg... more The following properties have been measured for mercury clusters: (1) ionisation potentials of Hg, by electron-impact ionisation, (2) dissociation energies of Hg; , and (3) mass spectra for negatively charged mercury cluster ions (n > 3). Cohesive energies for neutral and ...
Received 8 July l991) Photoabsorption cross sections for Ar, +, 3~n~80, and Xe"+, 3~n~30, cluster... more Received 8 July l991) Photoabsorption cross sections for Ar, +, 3~n~80, and Xe"+, 3~n~30, clusters have been measured. A single absorption maximum in the visible is observed for Ar", whose redshift with growing n is interpreted as a delocalization of the charge from a trimer to a tetramer ion. For Xe3+, two maxima, and for Xe, +, n~5, three maxima are observed. For n~5 the positive charge can localize onto either a trimer or a tetramer ion core, both surrounded by neutral atoms. The transition between the two isomers is faster than 10 ns.
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