Perfluoromethyl Fluorocarbonyl Peroxide, CF300C(0)F: Structure, Conformations, and Vibrational Spectra Studied by Experimental and Theoretical Methods

The conformational properties and the geometric structure of perfluoromethyl fluorocarbonyl peroxide, CF300C(O)F, have been studied by matrix IR spectroscopy, gas electron diffraction, and quantum chemical calculations (HF, B3LYP, and MP2 methods with 6-311G* basis sets). Matrix IR spectra imply a mixture of syn and anti conformers (orientation of the C=O bond relative to the 0—0 bond) with A = H - H = 2.16(22) kcal/mol. At room temperature, the contribution of the anti rotamer is about 3.0%. The 0—0 bond (1.422(15) A) is within the experimental uncertainties equal to those in related symmetrically substituted peroxides CF3OOCF3 and FC(O)OOC(0)F (1.419(20) and 1.419(9) A, respectively), and the dihedral angle (3(0000) (111(5)°) is intermediate between the values in these two compounds (123(4)° and 83.5(14)°, respectively).