A study of the basis set dependence of the geometry and proton affinity for a series of vinyl ethers and vinyl sulfides

Comparative calculations of most stable geometries and proton affinities for a series of vinyl ethers and vinyl sulfides are made using the 4–31G and 3–21G(*) bases. While 4–31G and 3–21G(*) proton affinities follow the same trends in the series, discrepancies arise for the molecular structures. Oxo carbenium ions turn out to be better stabilized than their thio analogs, and interesting features in the atomic charge patterns are pointed out.