4-(2-Hy-droxy-phen-yl)-3,5-di-thia-hepta-ne-dioic acid.

In the crystal of the title compound, C11H12O5S2, mol-ecules are linked by O-H⋯O hydrogen bonds and C-H⋯O inter-actions, forming a three-dimensional network.

(E)-3-(4-Meth-oxy-phen-yl)-3-[3-(4-meth-oxy-phen-yl)-1H-pyrazol-1-yl]prop-2-enal.

In the title mol-ecule, C20H18N2O3, the pyrazole ring forms a dihedral angle of 2.2 (1)° with its meth-oxy-phenyl substituent and a dihedral angle of 67.2 (1)° with the benzene substituent on the propenal unit. In the crystal, mol-ecules are connected by weak C-H⋯O hydrogen bonds, forming R 2 (2)(26) and R 2 (2)(28) cyclic dimers that lie about crystallographic inversion centres. These dimers are further linked through C-H⋯O and C-H⋯N hydrogen bonds, forming C(8), C(9), C(10) and C(16) chain motifs. These primary motifs are further linked to form secondary C 2 (2)(15) chains and R 2 (2)(18) rings.

1-(2,4-Dinitro-phen-yl)-3-phenyl-4-phenyl-sulfanyl-1H-pyrazole.

In the title mol-ecule, C(21)H(14)N(4)O(4)S, the pyrazole ring forms dihedral angles of 45.6 (1), 87.7 (1) and 27.4 (1)° with the phenyl, sulfur-substituted benzene and nitro-substituted benzene rings, respectively. In the crystal, mol-ecules are connected by weak C-H⋯O and C-H⋯N hydrogen bonds into layers parallel to (010).

(E)-3-Phenyl-3-(3-phenyl-1H-1-pyrazol-yl)-2-propenal.

In the title compound C(18)H(14)N(2)O, the pendant rings make dihedral angles of 66.1 (1)° and 13.9 (1) with the central ring. In the crystal, two mol-ecules form a cyclic centrosymmetric R(2) (2)(22) dimer through pairs of C-H⋯O bonds. These dimers are further connected into zigzag chains extending along the b axis through C-H⋯π and C-H⋯O inter-actions.

(E)-3-(4-Chloro-phen-yl)-3-[3-(4-chloro-phen-yl)-1H-pyrazol-1-yl]prop-2-enal.

In the title compound, C(18)H(12)Cl(2)N(2)O, the pyrazole ring is almost planar [r.m.s. deviation = 0.002 Å] while the two chloro-phenyl rings are twisted out from the plane of the pyrazole ring, making dihedral angles of 5.3 (1) and 65.34 (4)°. In the crystal, centrosymmetric R(2) (2)(24) dimers are formed about crystallographic inversion centres through a pair of C-H⋯Cl inter-actions. These dimers are further linked through a C-H⋯O hydrogen bond, forming a C(8) chain extending along the a axis. C-H⋯π inter-actions are also observed.