metal-organic compounds
The title compound, [La2(C8H3NO6)2(C8H4NO6)2(H2O)6]·2H2O, consists of dimeric units related by an inversion center. The two LaIII atoms are linked by two bridging bidentate carboxylate groups and two monodentate carboxylate groups. Each LaIII atom is nine-coordinated by six O atoms from five different carboxylate groups and three from water molecules. Hydrogen bonds between the water molecules and between the solvent water and a carboxylate O atom are observed in the structure. In the crystal packing, there are slipped π–π stacking interactions between the parallel benzene rings. Both hydrogen-bonding and π–π interactions combine to stabilize the three-dimensional supramolecular network.
organic compounds
In the crystal structure of the title compound, C21H21NO2, strong N—HO and O—HO hydrogen bonds exist. The keto–amine form is favoured over the enol–imine form in the tautomerism. Six-membered chelate rings formed by intramolecular hydrogen bonds increase the stability of the whole molecule. Intermolecular hydrogen bonds link adjacent units together, forming an infinite one-dimensional chain parallel to the a axis.
metal-organic compounds
In the title complex, [Mn(C8H4NO6)2(H2O)4]·2H2O, cyclic water tetramers forming one-dimensional metal–water chains have been observed. The water clusters are trapped by the co-operative association of coordination interactions and hydrogen bonds. The MnII ion resides on a center of symmetry and is in an octahedral coordination environment comprising two O atoms from two 5-carboxy-2-nitrobenzoate ligands and four O atoms from water molecules.
metal-organic compounds
In poly[[aquastrontium(II)]-μ6-4-nitrobenzene-1,3-dicarboxylato-κ7O1:O2:O2:O3:O3,O4:O4], [Sr(C8H3NO6)(H2O)]n, the SrII ion displays a distorted bicapped triangular prismatic configuration, defined by seven carboxyl O atoms from six symmetry-related ligands and one water molecule. The ligand molecules connect the SrII ions into a two-dimensional layered framework in the ac plane, with close OO contacts between the nitro groups and with each nitro group providing one acceptor O atom for a weak intermolecular C—HO hydrogen bond.