Clusters collision induced dissociation

Dalleska, N. R, Honma, K., Armentrout, P. B. (1993) Stepwise solvation enthalpies of protonated water clusters collision-induced dissociation as an alternative to equilibrium studies. J. Am. Chem. Soc. 115, 12125. 

Collision-induced dissociation mass spectrum of tire proton-bound dimer of isopropanol [(CH2)2CHOH]2H. The mJz 121 ions were first isolated in the trap, followed by resonant excitation of their trajectories to produce CID. Fragment ions include water loss mJz 103), loss of isopropanol mJz 61) and loss of 42 anui mJz 79). (b) Ion-molecule reactions in an ion trap. In this example the mJz 103 ion was first isolated and then resonantly excited in the trap. Endothennic reaction with water inside the trap produces the proton-bound cluster at mJz 121, while CID produces the fragment with mJz 61. 

Relatively few investigations involving palladium carbonyl clusters have been carried out, partly because palladium per se does not form stable, discrete homometallic carbonyl clusters at room temperature in either solid or solution states.114,917-922 Nevertheless, solution-phase palladium carbonyl complexes have been synthesized with other stabilizing ligands (e.g., phosphines),105,923 and carbon monoxide readily absorbs on palladium surfaces.924 Moreover, gas-phase [Pd3(CO)n]-anions (n = 1-6) have been generated and their binding energies determined via the collision-induced dissociation method.925... 

Key words clusters, ion mobility spectrometry, photoelectron spectroscopy, collision-induced dissociation, molecular structure optimization... 

Mass spectrometric investigation of gas phase clusters has come to play a significant role in cluster research because it is presently the only technique that allows size-dependent analysis of cluster beams. We anticipate that, in the near future, CMS studies utilizing tandem mass spectrometric techniques will be invaluable in confirming the importance of metastable decompositions and in determining the factors responsible for the enhanced intensities of various ions in the CMS. Such an instrument is currently under construction in our own labs, and we should soon have the ability to perform collision-induced dissociation studies on large vdW clusters. 

The Dmol program [10] has also been used to optimize the geometries for clusters of Nb with n = 2-10 [125] (Fig. 15), as well as to determine the bond dissociation energies. A rather good agreement is obtained with experimental values determined from collision induced dissociation energies by Hales et al. [142] as shown in Fig. 16. 

Bell RC, Zemski KA, Kerns KP, Deng HT, Castleman AW Jr (1998) Reactivities and collision-induced dissociation of vanadium oxide cluster cations. J Phys Chem A 102 1733... 

Gord JR, Bemish RJ, Freiser BS (1990) Collision-induced dissociation of positive and negative copper-oxide cluster ions generated by direct laser desorption ionization of copper-oxide. Int J Mass Spectrom Ion Processes 102 115... 

Spasov VA, Lee TH, Ervin KM (2000) Threshold collision-induced dissociation of anionic copper clusters and copper cluster monocarbonyls. J Chem Phys 112 1713... 

Note however, that the for the internal relaxation dynamics of the clusters this approach has to be used carefully as has been shown for the quantized fragmentation dynamics [28,38] revealed in kinematically complete experiments of collision induced dissociation [29]. 

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