Nuclear hyperfine interactions in the open shell complexes O2-HF and O2-DF

PHYS 597

Shenghai Wu, swu@chem.umn.edu, Galen Sedo, sedo@chem.umn.edu, Erik M. Grumstrup, and Kenneth R. Leopold, kleopold@chem.umn.edu. Department of Chemistry, University of Minnesota, 207 pleasant ST SE, Minneapolis, MN 55455
Magnetic hyperfine interactions provide a unique perspective on electron distributions in molecules. In this work, we report microwave spectra of the open shell complexes O2–HF and O2–DF in which magnetic hyperfine structure from both the H(D) and F nuclei has been resolved and fully analyzed. We find the somewhat counterintuitive result that the Fermi contact parameter on the hydrogen is so near zero as to be indeterminate, while that for the fluorine is considerably larger. We argue that this implies an interaction involving the transfer of spin polarization across the weak bond. The nuclear–electron spin dipolar interaction constants are more commensurate with the expected r -3 distance dependence. New structural information for the complex is obtained from HF nuclear–nuclear spin interaction and from the deuterium quadrupole coupling constant of the DF species.
 

PHYS Poster Session - Computational Spectroscopy and Reaction Dynamics
7:30 PM-10:00 PM, Wednesday, April 9, 2008 Morial Convention Center -- Hall A, Poster

Sci-Mix
8:00 PM-10:00 PM, Monday, April 7, 2008 Morial Convention Center -- Hall A, Sci-Mix

Division of Physical Chemistry

The 235th ACS National Meeting, New Orleans, LA, April 6-10, 2008