Accession Number:

ADA282652

Title:

Hydrogen Bonding and Molecular Orientation in Water/Fluorine Adlayers on Silver(110)

Descriptive Note:

Technical rept.

Corporate Author:

WASHINGTON UNIV SEATTLE

Report Date:

1994-07-11

Pagination or Media Count:

30.0

Abstract:

The orientation and hydrogen bonding interactions of water coadsorbed with atomic fluorine on Ag110 were examined with high resolution electron energy loss spectroscopy HREELS and time-of-flight measurements of electron stimulated desorption ion angular distribution TOF-ESDIAD. Water exhibits four stabilized adsorption states in the presence of fluorine, identified as the B, A1, A2, and A3 states in order of their decreasing desorption temperatures. The B state interacts with fluorine through one hydrogen bond with the other hydrogen remaining free as evidenced by an O-H stretching frequency of 3700cm. Water molecules in the A1 state interact through two strong hydrogen bonds in a ratio of one water molecule per fluorine atom and cause a 2x1 to 1x2 surface phase transition of fluorine. Surprisingly, TOF-ESDIAD measurements detect no H emission from either the B or A1 states indicating that all hydrogens are either pointed towards the surface or far enough away from the surface normal to escape detection by ESDIA-D. Instead, emission of only high mass ions OOHH2OF occurs in two beams along the 110 direction for the B state and along the 001 direction for the combined B A1 states. The A2 and A3 states of water hydrogen bond to the B and A1 states and exhibit vibrational spectra that approach that of ice, although the interaction with fluorine remains sufficiently strong to impart measurable spectral differences. Double layer modeling, Solvation, Fluorine adsorption, Water adsorption, Metalelectrolyte interface

Subject Categories:

  • Inorganic Chemistry
  • Atomic and Molecular Physics and Spectroscopy

Distribution Statement:

APPROVED FOR PUBLIC RELEASE