Sulphone structures. Part II. Crystal and molecular structure of N-p-tolylsulphonylbenzylamine, 1-methyl-3-p-tolylsulphonylaminoindole, 1-methyl-3-p-tolylsulphonyliminoindoline-2-spirocyclopentane, and 1,2,3,4-tetrahydro-1,2,4-trimethyl-4-p-tolylsulphonylamino-3-p-tolylsulphonyliminoquinoline