Electrochemical oxidation of iodide has been studied in the presence of 2-thioborbituric acid using cyclic voltammetry and controlled-potential coulometry. The results indicate that, the resulting iodine takes part in halogenations reaction with 2-thiobarbituric acid. In addition, the present data are indicative of the suitability of iodide as a quasi mediator for determination of 2-thiobar...

In the title mol-ecule, C(8)H(7)BrO(2), the carboxyl group is twisted by 76.2 (3)° from the benzene ring plane. In the crystal, mol-ecules are linked into inversion dimers through pairs of O-H⋯O hydrogen bonds. The dimers are further linked into layers parallel to the bc plane by weak C-H⋯O hydrogen bonds.

All non-H atoms of the title compound, C(7)H(7)NO(2)S, lie on a crystallographic mirror plane, with the two methyl-ene H atoms bis-ected by this plane. The crystal packing is characterized by inter-molecular C-H⋯O and O-H⋯N contacts, which link the mol-ecules into infinite zigzag chains parallel to [010].

The title compound, C(8)H(8)INO(4)S, is a halogenated sulfon-amide, a medicinally important class of organic compounds. In the crystal structure, inter-molecular O-H⋯O hydrogen bonds involving the carboxylic acid groups form characteristic centrosymmetric dimers. These dimers are further linked through centrosymmetric dimeric N-H⋯O inter-actions involving the amido H atom and a sulfonyl O atom....

In the title compound, C(15)H(11)FO(3), the aromatic rings are oriented at a dihedral angle of 69.26 (3)°. In the crystal structure, inversion dimers arise from pairs of inter-molecular O-H⋯O hydrogen bonds, and C-H⋯O hydrogen bonds further consolidate the packing. There are also C-H⋯π contacts between the benzoic acid and 2-fluoro-benzene rings.

In the title compound, C(13)H(10)N(2)O(4), the nitro N atom deviates by 0.031 (2) Å from the plane of the benzene ring to which it is attached. The aromatic rings are oriented at a dihedral angle of 50.6 (1)°. An intra-molecular N-H⋯O hydrogen bond occurs. In the crystal, inversion dimers are formed by pairs of O-H⋯O inter-actions.

In the title compound, C(8)H(7)ClO(2), the carboxyl group forms a dihedral angle of 74.83 (9)° with the benzene ring plane. In the crystal, mol-ecules are linked into inversion dimers by pairs of O-H⋯O hydrogen bonds. The dimers are linked into layers parallel to the bc plane by weak C-H⋯O inter-actions.