Huai-Hong Zhang

4-(6-Fluoro-1,2-benzisoxazol-3-yl)-1-[2-(2-methyl-4-oxo-6,7,8,9-tetra­hydro-4H-pyrido[1,2-a]pyrimidin-3-yl)eth­yl]piperidinium nitrate

In the risperidone cation of the title compound, C23H28FN4O2 +·NO3 −, the piperidine ring adopts a chair conformation and the tetrahydropyridine ring is disordered over two orientations in a 0.620 (11):0.380 (11) ratio. N—H⋯O, C—H⋯O and C—H⋯F hydrogen bonds are present in the crystal structure.

A blue-emitting organic compound 9-hydroxyl-3-hydroxyethyl-2-methyl-4H-pyrido[1,2-a]pyrimidin-4-one: Synthesis, crystal structure and luminescent properties

A blue-emitting organic compound, 9-hydroxyl-3-hydroxyethyl-2-methyl-4H-pyrido[1,2-a]pyrimidin-4-one (I), was synthesized by the reaction of 2-amino-3-hydroxylpridine with 2-acetylbutyrolactone. The crystal of the title compound in larger size was reported for the first time through the slow evaporation method. The whole molecule in the crystal is non-planar, but the two conjugated rings are almost co-planar (with an average dihedral angle of only about 1.621degrees). The hydroxyl group is in trans position to the pyrido[1,2-a]pyrimidin heterocyclic moiety. The molecules are linked by the N-HO, O-HO and C-HO hydrogen bonds into two-dimensional sheets. Additionally, the pi-pi interactions (average distance 3.3680 A) interconnect the sheets stabilizing the crystal structure. At room temperature, the compound exhibits an intense blue emission at 432 nm upon 323 nm excitation in the solid state. The simple EL device with the configuration of ITO/I + PMMA/Ag was fabricated, where the compound (I) was used as a main emitting material. The EL device fabricated had a maximum brightness of 289 cd m-2. The thermal stability of the compound was also investigated by thermogravimetric analysis (TGA).

Aqua­bis(2,3-dimethyl-4-oxo-4H-pyrido[1,2-a]pyrimidin-9-olato)nickel(II)

In the crystal structure of the mononuclear title complex, [Ni(C10H9N2O2)2(H2O)], the NiII ion is five-coordinated in a distorted square-pyramidal geometry by two N atoms and two O atoms from 2,3-dimethyl-4-oxopyrido[1,2-a]pyrimidin-9-olate ligands and one O atom from a water molecule. O—H⋯O hydrogen bonds between the coordinated water molecule and the ligand connect adjacent molecules, forming a ribbon parallel to the b axis.

Aqua­bis(2-methyl-4-oxopyrido[1,2-a]pyrimidin-9-olato)zinc(II) monohydrate

The crystal structure of the title compound, [Zn(C9H7N2O2)2(H2O)]·H2O, involves discrete mononuclear complex molecules. The special positions on the rotation twofold axis are occupied by ZnII and O atoms of the coordinated and uncoordinated water molecules. The coordination around the ZnII atom can be described as transitional from trigonal-bipyramidal to square-pyramidal. The two chelating 2-methyl-4-oxopyrido[1,2-a]pyrimidin-9-olate ligands and the coordinated water molecule form the Zn coordination. O—H⋯O hydrogen bonds between the coordinated water molecule and the ligand and between the uncoordinated water molecule and the ligand dominate the crystal packing.

Aqua­[4-chloro-2-(2-pyridylmethyl­imino­meth­yl)phenolato]copper(II) nitrate monohydrate

In the title mononuclear complex, [Cu(C13H10ClN2O)(H2O)]NO3·H2O, the CuII atom is four-coordinated by two N atoms and one O atom of the tridentate Schiff base ligand and one O atom from the coordinated water molecule in a slightly distorted square-planar configuration. The nitrate ion interacts with the copper center [Cu1⋯O3 = 2.579 (4) Å]. In the crystal, the cations, anions and water molecules are linked by O—H⋯O and O—H⋯N hydrogen bonds.

Bis[2-methoxy-6-(3-pyridylmethyliminomethyl)phenolato-κ2N,O]copper(II)

In the title complex, [Cu(C14H13N2O2)2], the CuII ion is located on a crystallographic inversion center. The complex thus adopts a square-planar trans-[CuN2O2] coordination geometry, with the CuII ion coordinated by two 2-methoxy-6-(3-pyridylmethyliminomethyl)phenolate (Schiff base) ligands. The aryl and pyridyl rings in the Schiff base are almost perpendicular to each other, with a dihedral angle of 87.61 (6)° between the planes of the two six-membered rings. The pyridyl ring was refined using a disorder model with approximately 70% occupancy for the major component

Bis{μ-2-[1-(2-Pyridylmethyl­imino)eth­yl]phenolato}bis­[azido­copper(II)]

The title compound, [Cu2(C14H13N2O)2(N3)2], was synthesized by the reaction of Cu(NO3)2·3H2O with the Schiff base 2-[1-(2-pyridylmethylimino)ethyl]phenol (HL) in methanol–water solution, adding NaN3 as the bridging ligand. The asymmetric unit contains one half-molecule, the other half being generated by the inversion center. Each CuII atom shows a slightly distorted trigonal-pyramidal geometry formed by two N atoms and one O atom from one Schiff base ligand, by another O atom of a second Schiff base ligand and by an azide N atom. The crystal structure is stabilized by intermolecular C—H⋯N hydrogen bonds.

Di-μ-chlorido-bis­[aqua­(2,2′-bipyridine-κ2N,N′)chloridocobalt(II)]

The title complex, [Co2Cl4(C10H8N2)2(H2O)2], is composed of two CoII atoms, each hexacoordinated by three Cl atoms, one 2,2′-bipyridine (bpy) ligand and one water molecule in a distorted octahedral geometry. Neighboring CoII atoms are linked together by two Cl bridges, forming a dinuclear CoII complex with inversion symmetry. There are intermolecular O—H⋯Cl hydrogen bonds and intermolecular π–π stacking interactions between adjacent bpy ligands [centroid–centroid distance = 3.617 (2) Å] in the structure.

μ(3)-Oxido-hexa-μ(2)-pivalato-tris[(methanol-κO)cobalt(III)] chloride.

The crystal structure of the title compound, [Co3(C5H9O2)6O(CH4O)3]Cl, consists of trinuclear CoIII complex cations and chloride anions. The CoIII cation has site symmetry m, and is coordinated by four oxygen atoms from four bridging pivalate groups, one central O anion and a methanol oxygen atom, forming a distorted octahedral geometry. The coordinated methanol molecule is located on a crystallographic special position, the C and O atoms being located on the mirror plane. The central O anion lies in the crystallographic position, and acts as a μ 3-O bridge, linking three equivalent CoIII cations and generating the oxo-centered trinuclear CoIII complex. The chloride anion, which acts as the counter-ion, is located on crystallographic position. O—H⋯Cl hydrogen bonding between the Cl anion and hydroxyl group of the coordinated methanol molecule links the molecules into a supramolecular network.

Aqua­(1,10-phenanthroline-κ2 N,N′)bis­(trimethyl­acetato)-κ2 O,O′;κO-cobalt(II)

In the title compound, [Co(C5H9O2)2(C12H8N2)(H2O)], the CoII atom is coordinated in a distorted octahedral environment by three carboxyl O atoms of two trimethylacetate ligands, one aqua O atom and two N atoms from 1,10-phenanthroline. The crystal structure is stabilized by O—H⋯O hydrogen bonds and π–π stacking interactions [interplanar distance between interdigitating 1,10-phenanthroline ligands = 3.378 (2) Å].