The title compound, C(10)H(10)O(4), crystallizes with the well-known carb-oxy-lic acid dimer-forming R(2) (2)(8) hydrogen-bond motif. Chains approximately parallel to (-1-12) are then built through C(methyl-ene,phen-yl)-H⋯O(carbon-yl) inter-actions [C(6) and C(8) motifs] with one (meth-yl)C-H⋯π inter-action providing inter-planar binding. The weakness of the latter inter-action is consistent wi...

The title compound, C5H9NO4·H2O, is an isomer of the α-amino acid glutamic acid that crystallizes from water in its zwitterionic form as a monohydrate. It is not one of the 20 proteinogenic α-amino acids that are used in living systems and differs from the natural amino acids in that it has an α-methyl group rather than an α-H atom. In the crystal, an O-H⋯O hydrogen bond is present between the ...

The title compound, C(4)H(3)BrO(4), was obtained from a solution of meso-2,3-dibromo-succinic acid and vanadium(IV) oxide. The crystals are isostructural with chloro-maleic acid and the mol-ecule has two geometrically different carboxyl groups, one of which has delocalized C-O bonds and is essentially coplanar with the olefinic bond plane [give dihedral angle 15.08 (16)°], whereas the other has...

Nano silica sulfuric acid as a solid acid, was described to be an effective catalyst for one-pot three-component reaction of kojic acid, aryl aldehydes and indoles for the preparation of 2-substituted aryl (indolyl) kojic acid derivatives. The catalyst was prepared by combination of chlorosulfonic acid to nano silica gel. The size of nanoparticles were observed with SEM.All prepared compounds w...

The title compound, C(8)H(9)NO(4)S, is of inter-est as a precursor to biologically active sulfur-containing heterocyclic cmpounds. The crystal structure displays the classical O-H⋯O inter-molecular hydrogen bonding typical for carboxylic acids forming dimers. Symmetry-related dimers are, in turn, linked through head-to-tail pairs of inter-molecular N-H⋯O inter-actions, giving rise to a zigzag c...

In the crystal structure of the title compound, C(8)H(6)Br(2)O(2), the carboxyl groups are involved in pairs of O-H⋯O hydrogen bonds, which link the mol-ecules into inversion dimers.

In the title compound, C(11)H(14)O(2), the dihedral angle between the CCOO carboxyl unit and the benzene ring is 85.37 (7)°. In the crystal, the mol-ecules are linked into inversion dimers by pairs of O-H⋯O hydrogen bonds.

The title compound, C(9)H(8)O(2)S(2), can be used as a chain transfer agent and may be used to control the behavior of polymerization reactions. O-H⋯O hydrogen bonds of moderate character link the mol-ecules into dimers. In the crystal, the dimers are linked into sheets by C-H⋯O inter-actions, forming R(4) (2)(12) and R(2) (2)(8) edge-fused rings running parallel to [101]. There are no inter-mo...

The title compound, 2-(CH(3)CH(2)CH(2)CH(2)O)C(6)H(4)B(OH)(2), exists as a centrosymmetric hydrogen-bonded dimer. Dimers are linked via C-H⋯π and π-π [with closest C⋯C contact of 3.540 (3) Å] inter-actions to produce a two-dimensional array.