The title compound, C(14)H(11)N(3)O(5), is essentially planar, with an r.m.s. deviation for the non-H atoms of 0.0832 (3) Å. In the crystal, O-H⋯O and N-H⋯O hydrogen bonds link adjacent mol-ecules into layers parallel to (101). These layers are further connected into a three-dimensional network via C-H⋯O inter-actions. In addition, a π-π inter-action occurs between the aromatic rings [centroid-centroid distance = 3.5425 (8) Å]. An intra-molecular O-H⋯N hydrogen bond is also observed.
The metal atom in the title compound, [Cd(C(15)H(13)N(2)O(4))(2)]·2C(2)H(6)OS, is twice O,N,O'-chelated by two symmetry-related Schiff base ligands to define a trans-N(2)O(4) octa-hedral geometry. Each anion occupies meridional sites of the octa-hedron; the metal atom lies on a special position of site symmetry 2. The dimethyl sulfoxide mol-ecule is a hydrogen-bond acceptor to the -NH- unit, and O-H⋯O hydrogen bonds link mol-ecules into a supra-molecular chain.
Each of the two independent mol-ecules of the title comound, C(14)H(20)N(2)O(3), exists in the zwitterionic form as the imino N atoms are protonated. The =N-H unit forms an intra-molecular hydrogen bond to the negatively charged O atom, and also a weaker intermolecular N-H⋯O bond, the latter resulting in inversion dimers.
The asymmetric unit of the crystal structure of the title compound, [Ni(C(14)H(19)N(2)O(3))(2)], contains two independent Ni(II) complex mol-ecules, with the metal atoms each located on a center of inversion. Each metal atom is chelated by two Schiff base anions in a distorted square-planar coordination environment.
The central Cd(II) atom in the trinuclear title compound, [Cd(3)(C(14)H(19)N(2)O(3))(2)(CH(3)COO)(4)], lies on a center of inversion and is bonded to the O atoms of four acetate groups as well as to the phenolate O atoms of the mono-deprotonated Schiff base ligands in a distorted all-trans octa-hedral geometry. Two of the acetate groups function in a μ(2)-bridging mode, while the other two each chelate to the terminal Cd(II) atom and simultaneously bind to the central metal atom in a κ(3)-bonding mode. The Schiff base anions N,O-chelate to the terminal metal atoms. The morpholine ring assumes a chair conformation.
The Schiff base mol-ecule of the title compound, C(15)H(14)N(2)O(4)·H(2)O, adopts a trans configuration with respect to the C=N double bond; the Schiff base itself is almost planar (r.m.s. deviation for all non-H atoms = 0.040 Å). The amido N atom is the hydrogen-bond donor to the water mol-ecule, which is the hydrogen-bond donor to the hydr-oxy groups of two neighboring mol-ecules. One of the hydroxyl groups acts as an intra-molecular and the other as an inter-molecular hydrogen-bond donor.
The pyridine-coordinated Cu(II) atom in the title Schiff base complex, [Cu(C(15)H(11)N(3)O(5))(C(5)H(5)N)], is O,N,O'-chelated by the doubly deprotonated Schiff base ligand. The metal centre is in a square-planar coordination geometry.
The Schiff base mol-ecule of the title compound, C(15)H(14)N(2)O(4)·C(3)H(7)NO, adopts a trans configuration with respect to the C=N double bond; the Schiff base itself is nearly planar (r.m.s. deviation 0.20 Å). The amido N atom is a hydrogen-bond donor to the dimethyl-formamide solvate mol-ecule. One of the hydr-oxy groups forms an intra-molecular hydrogen bond to the N atom of the C=N double bond, whereas the other forms an inter-molecular hydrogen bond to the carbonyl group.