Collect. Czech. Chem. Commun. 1980, 45, 1236-1250

Quantum chemical study of sulfonium ylides: Structure, charge distribution and dipole moments

Vladimír Krála, Zdeněk Arnolda, Václav Jehličkab and Otto Exnera

a Institute of Organic Chemistry and Biochemistry, Czechoslovak Academy of Sciences, 166 10 Prague 6
b Department of Physical Chemistry, Prague Institute of Chemical Technology, 166 28 Prague 6


The geometry, charge distribution and dipole moments of parent sulfonium ylide - dimethylsulfoniomethylide (I) - and a series of stabilized sulfonium ylides, including 2-dimethylsulfuranylidene-1,3-cyclopentanedione (VI) prepared in this study, was investigated using the CNDO/2, PCILO and ab initio methods. Values of dipole moments, calculated by quantum chemical methods (CNDO/2 with sp and spd bases, ab initio with the STO-3G basis) as well as by the method of empirical bond moments, are compared with the experimental values determined in dioxane or benzene. Dipole moments of several related ammonium ylides were also studied.