Intramolecularnonbonded S...N interactions in the crystal structures of the derivatives (7a-d) of sodium rabeprazole (1) and an intermolecular nonbonded S...N interaction between ethylmethylsulfoxide and pyridine in a solution were recognized. These results made us estimate that the intramolecularnonbonded S...N interaction existed in 1 and its derivatives in a solution, and formed the 4-membered