Derivatives of 1,3-thiazolidin-2,4-dione appended to biphenyl ring viz., 7-9, 16-18 were prepared. The newly synthesized compounds were confirmed by IR, NMR ( 1 H and 13 C) MS and elemental analyses. Single crystal X-ray diffraction study was carried out for one of the final compounds 9.

In the title compound, C15H15Cl2N2O+·Br−, the angle between the least‐squares planes of the di­chloro­phenyl moiety and the pyridine ring is 20.23 (9)°. The molecular packing is mainly influenced by intermolecular C—H⋯Br hydrogen‐bond interactions. The mol­ecules form an extended chain along the b axis, through C—H⋯Br hydrogen bonds.

The title compound, C19H17NO3S, crystallizes in the monoclinic space group P21/c, with four mol­ecules in the unit cell. The structure contains a spiro‐carbon connecting a bi­cyclo‐octane group, consisting of two fused five‐membered rings, to an ace­naphthyl­ene moiety. The five‐membered ring containing the S atom is in an envelope conformation. The conformation of the other five‐membered ring of the bi­cyclo‐octane moiety is close to a half‐chair. The methoxycarbonyl group is equatorially substituted.

Key indicatorsSingle-crystal X-ray study T = 298 K Mean (C-C) = 0.003 Å Disorder in main residue R factor = 0.059 wR factor = 0.183 Data-to-parameter ratio = 14.9For details of how these key indicators were automatically derived from the article, see

Key indicatorsSingle-crystal X-ray study T = 273 K Mean (C-C) = 0.002 Å Disorder in main residue R factor = 0.049 wR factor = 0.141 Data-to-parameter ratio = 13.1 For details of how these key indicators were automatically derived from the article, see

Key indicatorsSingle-crystal X-ray study T = 293 K Mean '(C±C) = 0.008 A Ê R factor = 0.056 wR factor = 0.162 Data-to-parameter ratio = 12.5For details of how these key indicators were automatically derived from the article, seeThe title compound, (C 9 H 8 N) 2 [Cr 2 O 7 ], crystallizes in the monoclinic space group P2 1 /c, with eight cations and four anions in the unit cell. The quinolinium cations and a dichromate anion are connected through NÐHÁ Á ÁO and CÐHÁ Á ÁO intermolecular hydrogen bonds and by aromatic %± %-stacking interactions. The dichromate geometry is normal, with a CrÐO(bridging)ÐCr angle of 135.1 (2) .

Key indicatorsSingle-crystal X-ray study T = 273 K Mean (C-C) = 0.003 Å R factor = 0.050 wR factor = 0.134 Data-to-parameter ratio = 13.2 For details of how these key indicators were automatically derived from the article, see

The title mol­ecular salt, C13H15N2 +·Br−, crystallized with two independent ion pairs (A and B) in the asymmetric unit. In the cations, the planes of the pyridine and benzene rings are inclined to one another by 79.32 (8) and 82.30 (10)° in ion pairs A and B, respectively. In the crystal, the anions and cations are connected by N—H⋯Br hydrogen bonds, forming a centrosymmetric tetra­mer-like unit enclosing an R 8 4(16) ring motif. These units are linked via C—H⋯Br hydrogen bonds, forming a three-dimensional network.