Hydrogen formation in the reaction of Zn+ (H2O)n with HCl.
Hydrated singly charged zinc cations Zn (H2O)n, n approximately 6-53, were studied by Fourier transform ion cyclotron resonance (FT-ICR) mass spectrometry. Black-body radiation induced dissociation results exclusively in sequential loss of individual water molecules. In the reaction of Zn+ (H2O)n with gaseous HCl, Zn is oxidized and hydrogen reduced when a second HCl molecule is taken up, leading to the formation of ZnCl+ (HCl)(H2O)n-m cluster ions and evaporation of atomic hydrogen together with m H2O molecules. The results are compared with earlier studies of Mg+ (H2O)n, for which hydrogen formation is already observed without HCl in a characteristic size region. The difference between zinc and magnesium is rationalized with the help of density functional theory calculations, which indicate a distinct difference in the thermochemistry of the reactions involved. The generally accepted hydrated electron model for hydrogen formation in Mg+ (H2O)n is modified for zinc to account for the different reactivity.
Department Chemie, Physikalische Chemie 2, Technische Universität München, Lichtenbergstr. 4, D-85747 Garching, Germany. beyer@ch.tum.de
Brigitte S
BS
Fox-Beyer
Zheng
Z
Sun
Iulia
I
Balteanu
O Petru
OP
Balaj
Martin K
MK
Beyer
D002412:Cations / Q000737:chemistry; D003198:Computer Simulation; D006851:Hydrochloric Acid / Q000737:chemistry*; D006859:Hydrogen / Q000737:chemistry*; D008956:Models, Chemical; D013816:Thermodynamics; D014867:Water / Q000737:chemistry*; D015032:Zinc / Q000737:chemistry*
D002412:Cations; D014867:Water; D006859:Hydrogen; D015032:Zinc; D006851:Hydrochloric Acid