New chiral sulfoxides (RS, S)-3,(SS, S)-3,(RS, S)-4, and (SS, S)-4 and known chiral sulfoxides (RS)-5,(RS)-6, and (RS)-7 were synthesized, and the stereochemistry of the new sulfoxides (RS, S)-3 and (RS, S)-4 was determined by X-ray crystallographic analysis. In their crystallographic structures, the intramolecular nonbonded S⊙⊙⊙ O close contacts were recognized. Analyses of several sulfoxide complexes including rac-11 with N, N- ...