Effect of Fluorination on the Conformational Properties of Methyl Vinyl Ether

The geometric structures of methyl trifluorovinyl ether, CH 3 OC(F) CF 2 (MTVE), and perfluoromethyl vinyl ether, CF 3 OC(F) CF 2 (PMVE), were determined by gas electron diffraction and ab initio calculations (HF/3-21G and MP2/6-31G*). The orientation of the O−C(sp 3 ) bond changes upon fluorination of the vinyl group from synperiplanar (φ(C C−O−C) = 0°) in methyl vinyl ether to anticlinal (φ(C C−O−C) = 111(4)° in MTVE and 104(2)° in PMVE). The effects of partial and perfluorination on the structure and conformational properties of methyl vinyl ether are discussed.