Charge delocalization dynamics of ammonia in different hydrogen bonding environments : free clusters and in liquid water solution

• Valence and core level photoelectron spectra and Auger electron spectra of ammonia in pure clusters have been measured. The Auger electro  spectra of gas-phase ammonia, pure ammonia clusters and ammonia in   aqueous solution are compared and interpreted via ab initio calculations of the Auger spectrum of the ammonia monomer and dimer. The calculations reveal that the final two-hole valence states can be   delocalized over both ammonia molecules. Features at energies   pertaining to delocalized states involving one, or more, hydroge  bonding orbitals can be found in both the ammonia cluster Auger   electron spectrum and in that of the liquid solvated molecule. The lower Coulombic repulsion between two delocalized valence final state holes gives higher kinetic energy of the Auger electrons which is also   observed in the spectra. This decay path-specific to the condensed   phase-is responsible for more than 5% of the total cluster Auger intensity. Moreover, this interpretation is also applicable to the   solid phase since the same features have been observed, but not assigned, in the Auger spectrum of solid ammonia.

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NATURVETENSKAP  -- Fysik (hsv//swe)

NATURAL SCIENCES  -- Physical Sciences (hsv//eng)

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Physics

Fysik

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