organic compounds
In the three spiroacenaphthylene structures 5′′-[(E)-2,3-dichlorobenzylidene]-7′-(2,3-dichlorophenyl)-1′′-methyldispiro[acenaphthylene-1,5′-pyrrolo[1,2-c][1,3]thiazole-6′,3′′-piperidine]-2,4′′-dione, C35H26Cl4N2O2S, (I), 5′′-[(E)-4-fluorobenzylidene]-7′-(4-fluorophenyl)-1′′-methyldispiro[acenaphthylene-1,5′-pyrrolo[1,2-c][1,3]thiazole-6′,3′′-piperidine]-2,4′′-dione, C35H28F2N2O2S, (II), and 5′′-[(E)-4-bromobenzylidene]-7′-(4-bromophenyl)-1′′-methyldispiro[acenaphthylene-1,5′-pyrrolo[1,2-c][1,3]thiazole-6′,3′′-piperidine]-2,4′′-dione, C35H28Br2N2O2S, (III), the substituted aryl groups are 2,3-dichloro-, 4-fluoro- and 4-bromophenyl, respectively. The six-membered piperidine ring in all three structures adopts a half-chair conformation, the thiazolidine ring adopts a slightly twisted envelope and the pyrrolidine ring an envelope conformation; in each case, the C atom linking the rings is the flap atom. In all three structures, weak intramolecular C—HO interactions are present. The crystal packing is stabilized through a number of intermolecular C—HO and C—HX interactions, where X = Cl in (I) and F or S in (II), and C—HO interactions are observed predominantly in (III). In all three structures, molecules are linked through centrosymmetric ring motifs, further tailored through a relay of C—HX [Cl in (I), Br in (II) and O in (III)] interactions.