Krypton, cluster structure

Figure 3 Mass spectmm of krypton clusters, grown in a supersonic expansion and ionized by electron impact. The cluster size and assumed cluster structure of particularly prominent mass peaks is indicated.

Nickel carbonyl radicals show an even greater tendency than cobalt carbonyls to cluster in a krypton matrix. Three binuclear nickel carbonyls have been detected by EPR spectroscopy in the products of y-irradiated Ni(CO)4 in Kr, yet no mononuclear species has been positively identified (65). 13C hyperfine structure has... 

Computer simulation of molecular dynamics is concerned with solving numerically the simultaneous equations of motion for a few hundred atoms or molecules that interact via specified potentials. One thus obtains the coordinates and velocities of the ensemble as a function of time that describe the structure and correlations of the sample. If a model of the induced polarizabilities is adopted, the spectral lineshapes can be obtained, often with certain quantum corrections [425,426]. One primary concern is, of course, to account as accurately as possible for the pairwise interactions so that by carefully comparing the calculated with the measured band shapes, new information concerning the effects of irreducible contributions of inter-molecular potential and cluster polarizabilities can be identified eventually. Pioneering work has pointed out significant effects of irreducible long-range forces of the Axilrod-Teller triple-dipole type [10]. Very recently, on the basis of combined computer simulation and experimental CILS studies, claims have been made that irreducible three-body contributions are observable, for example, in dense krypton [221]. 

Van der Waals complexes were observed between two molecules of 1,2,4,5-tetrazine (la) and helium, argon, krypton, xenon, hydrogen, water, hydrochloric acid, acetylene or benzene 28 36- 396-420 jn coi,j environment of a jet expansion. In favorable systems it has been possible to determine the ground and excited state geometry of the cluster by laser spectroscopy. From these structures, it has been found that 1,2,4,5-tetrazine possesses a number of different binding sites. Helium and argon bind to the equivalent sites above and below the ring.28-30 The predominant interaction in these clusters is presumably the attractive dispersion force. 

Modem supersonic molecular beam techniques provide a direct way to study the stability and valence electron structure of noninteracting, isolated atomic clusters. One of the most widely studied properties is the threshold for photo-ionization and its dependence on cluster size. In Fig. 4.20 we reproduce some experimental results for argon-, krypton-, xenon- (Gantefor et al., 1989), and mercury-clusters (Rademann et al.. 

S. Hirabayashi, K.M.T. Yamada, Infrared spectra and structure of water clusters trapped in argon and krypton matrices. J. Mol. Struct. 795(1-3), 78-83 (2006)... 

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