Hydrogen Bonding and Molecular Orientation in Water/Fluorine Adlayers on Silver(110)
Abstract
The orientation and hydrogen bonding interactions of water coadsorbed with atomic fluorine on Ag(110) 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 3700/cm. 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 (O+/OH+/H2O+/F+) 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, Metal/electrolyte interface
Document Details
- Document Type
- Technical Report
- Publication Date
- Jul 11, 1994
- Accession Number
- ADA282652
Entities
People
- A. Krasnopoler
- A. L. Johnson
- E. M. Stuve
Organizations
- University of Washington