Révész, Ágnes and Rokob, Tibor András and Maász, Gábor and Márk, László and Hevér, Helga and Drahos, László and Vékey, Károly (2013) Fragmentation, structure, and energetics of small sodium formate clusters : evidence for strong influence of entropic effects. International Journal of Mass Spectrometry, 354. pp. 292-302.
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Abstract
The behavior of small cationic sodium formate clusters [NaOOCH]nNa+ was studied using a combination of experimental and theoretical approaches. Energy-dependent tandem mass spectra were measured using a triple quadrupole and an ion trap type instrument, while structure and energetics were obtained from density functional theory calculations. Analysis of the relative abundances and fragmentation patterns indicate the existence of certain unstable cluster sizes, like the tetramer [NaOOCH]4Na+. This observation is in contrast to alkali halides, where this species has enhanced stability. Surprisingly, this ‘anti-magic’ sodium formate cluster is shown to be compact, energetically low-lying by quantum chemical calculations. The apparent contradiction can be explained by taking into account entropy effects as calculated dissociation Gibbs free energy values show remarkably improved agreement with experimental trends. Fragmentation of these clusters is a good example of reactions that are predominantly directed by entropy and not by energy constraints.
| Item Type: | Article |
|---|---|
| Subjects: | Q Science / természettudomány > QD Chemistry / kémia > QD02 Physical chemistry / fizikai kémia |
| Depositing User: | Tibor András Rokob |
| Date Deposited: | 03 Dec 2013 19:38 |
| Last Modified: | 04 Dec 2013 08:20 |
| URI: | http://real.mtak.hu/id/eprint/7749 |
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- Fragmentation, structure, and energetics of small sodium formate clusters : evidence for strong influence of entropic effects. (deposited 03 Dec 2013 19:38) [Currently Displayed]
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