The crystal structures and Hirshfeld surface analyses of three Schiff bases, namely (E)-N'[4- (piperidin-1-yl) benzylidene] benz enesulf ono hydr azide, C18H21N3O2S, (I), (E)-4-methyl-N'[4- (piperidin-1-yl)benzylidene] benzene-sulfonohydrazide, C19H23N3O2S, (II), and (E)-4-chloro-N'[4-(piperidin-1-yl)benzylidene]benzenesulfonohydrazide, C18H20CIN3O2S, (III), derived from arylsulfonohydrazides and 4-(piperidin-4-yl)benzaldehyde have been analysed to investigate the effect of substituents on the structural parameters. All three structures crystallize in monoclinic crystal systems, in the space groups P2(1)/c for (I) and (II), and C2/c for (III). Compound (III) contains two independent molecules in the asymmetric unit and sixteen molecules per unit cell, while (I) and (II) both have one and four molecules, respectively, in their asymmetric units and unit cells. In all cases, the central part of the molecule is twisted at the S atom. In the crystals, the molecules are linked via N-H center dot center dot center dot O hydrogen bonds, forming chains. Two-dimensional fingerprint plots of various interatomic contacts show that the major contributions are from H center dot center dot center dot H interactions.

NP thanks the Department of Science and Technology, Government of India, New Delhi, for a research fellowship under its PURSE Program. BTG thanks the University Grants Commission, Government of India, New Delhi, for a special grant under a UGC-BSR one-time grant to faculty.