EFFECT OF FLUORINATION ON THE CONFORMATIONAL PROPERTIES OF METHYL VINYL ETHER

The geometric structures of methyl trifluorovinyl ether, CH3OC(F)=CF2 (MTVE), and perfluoro-methyl vinyl ether, CF3OC(F)=CF2 (PMVE), were de termined 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 up on fluorination of the vinyl group from synperiplanar (phi(C=C-O-C) = 0 degrees) in methyl vinyl ether to anticlinal (phi(C=C-O-C) = 111(4)d egrees in MTVE and 104(2)degrees in PMVE). The effects of partial and perfluorination on the structure and conformational properties of meth yl vinyl ether are discussed.