High-resolution nuclear-magnetic-resonance spectra of hydrocarbon groupings - V. ABCX spectra of vinyl fluoride and 3-methylbut-l-ene

Some general properties of ABCX-type spectra are discussed. It is shown that it is possible to deduce from such spectra the relative signs of all inter-nuclear coupling constants. Analyses are presented of the hydrogen (proton) spectra from the vinyl groups of vinyl fluoride and 3-methylbut-l-ene, and of the fluorine spectrum of the former molecule. It is shown that all HF coupling constants in vinyl fluoride are of the same sign as the cis and trans HH coupling constants.