(E)-Ethyl 2-cyano-3-(3,4-dihydr­oxy-5-nitro­phen­yl)acrylate

The title compound, C12H10N2O6, was synthesized via a Knoevenagel condensation and crystallized from ethanol. In the crystal, strong classical inter­molecular O—H⋯O hydrogen bonds and weak C—H⋯N contacts link the mol­ecules into ribbons extending along [010]. Intra­molecular O—H⋯O and C—H⋯N contacts support the planar conformation of the mol­ecules (mean deivation 0.0270 Å)

Bis{2-[(1H-pyrrol-2-yl)methyl­imino­meth­yl]phenolato-κ2 N,O}zinc(II)

In the title compound, [Zn(C12H11N2O)2], the ZnII atom, lying on an inversion center, is coordinated by two O atoms and two N atoms from two salicylal Schiff base ligands in a distorted square-planar geometry. A three-dimensional network is formed by inter­molecular C—H⋯N hydrogen bonds and C—H⋯π contacts

Aqua­bis(5-methyl­pyrazine-2-carboxyl­ato)zinc(II) trihydrate

In the title compound, [Zn(C6H5N2O2)2(H2O)]·3H2O, the ZnII centre is five-coordinated by two O,N-bidentate Schiff base ligands and one O atom from a water mol­ecule in a slightly distorted square-pyramidal geometry. In the crystal, the complex and uncoordinated water mol­ecules are linked by O—H⋯O, O—H⋯N and C—H⋯O hydrogen bonds, forming a three-dimensional network

Diaqua­{6,6′-dimeth­oxy-2,2′-[ethane-1,2-diylbis(nitrilo­methyl­idyne)]diphenolato-κ2 O,N,N′,O′}manganese(III) perchlorate 18-crown-6 hemisolvate monohydrate

In the cation of the title compound, [Mn(C18H18N2O4)(H2O)2]ClO4·0.5C12H24O6·H2O, the MnIII ion is coordinated by two water O atoms, and two O atoms and two N atoms from the tetradentate 6,6′-dimeth­oxy-2,2′-[ethane-1,2-diylbis(nitrilo­methyl­idyne)]di­phenolate ligand, completing a distorted octa­hedral geometry. One O atom of the 18-crown-6-ether is disordered over two positions with occupancies of 0.70 (2) and 0.30 (2)