Theoretical Investigation on Hyperfine Structures of Perfluoropolyether Radicals

摘要

The geometries of CF3OCF2·, CF3OCFCF3· and CF3OCF2CF2· radicals were investigated by density func-tional theory(DFT) method. The calculated results indicate that all the three radicals have pyramidal shapes at their centers, and the αC is one top of the pyramids. Based on the DFT optimized geometries, the hyperfine coupling con-stants(hfcc’s) of the 19F atoms of the three radicals were calculated by B3LYP, MP2(full) and QCISD(full) methods. The calculated values agree with the experimental values, especially for the a values of Fα, the a values are 125.6×10–4, 104.2×10–4, and 83.2×10–4 T of CF3OCF2·, CF3OCFCF3· and CF3OCF2CF2·, respectively. These results better explain the experimental observation.