Structural studies on perfluorinated ethers

Ab-initio Hartree-Fock calculations with minimal (STO-3G) and split valence (4-31G) basis sets have been used to obtain optimized geometries for several perfluorinated ethers. The results from the 4-31G basis set are in good agreement with the experimental structure for perfluorodimethyl ether; the STO-3G basis set provides good overall agreement for bond angles and C-C and C-F bond lengths. The structures of two other perfluorinated ethers, which serve as useful models for perfluorinated polyethers, were also investigated. Since these are considered large for ab-initio calculations the STO-3G basis was used to obtain the optimized geometry. These latter results along with those for the split valence basis set for perfluorinated dimethyl ether provide a useful assessment of the geometry of polyperfluorinated ethers. © 1985 American Chemical Society.