Turganbay S. Iskenderov

Synthesis and structure of diaqua-bis(ethylenediamine)copper(II) salts with anions of carbamic acids

Abstract Two complexes of diaqua-bis(ethylenediamine)copper(II) with anions of N-car☐yglycine and ethylenediaminebiscar☐ylic acid [Cu(en)2(H2O)](OOCCH2NHCOO) · H2O (1) and [Cu(en)2(H2O)2](OOCNHCH2CH2NHCOO) · 2H2O (2) were synthesized and investigated by single-crystal X-ray analysis and IR spectroscopy. Compound 1 was obtained by direct synthesis upon interaction of copper powder with glycine hydrochloride in methanol solution upon heating in air. Compound 2 was isolated as a result of a reaction between a copper(II) anionic complex with pyruvoylamide oxime (H2pox) of composition K[Cu(pox)(Hpox)] with ethylenediamine and formaldehyde in methanol solution. In both cases formation of carbamate anions is connected with uptake of atmospheric carbon dioxide by the reaction mixtures. The crystal structures of 1 and 2 comprise [Cu(en)2H2O)2]2+ cations, carbamic acids anions and solvate water molecules. The complex cations of 1 and 2 consist of two ethylenediamine molecules coordinated in the equatorial plane [Cu-N = 2.007(3)–2.024(3)A for 1 and 1.996(2) and 2.022(2)A˚ for 2], and water molecules occupying the apical positions of distorted octahedral [Cu-O = 2.591(3) and 2.741(3)A˚ for 1 and 2.556(3)A˚ for 2]. The extended hydrogen bond system in 1 and 2 unites the elements of the structures.

(2RS)-3-Hydr-oxy-2-methyl-2-(2-pyrid-yl)imidazolidine-4-one.

The title structure, C9H11N3O2, is a racemate. The chiral centre is situated at the N—C—N C atom of the imidazolidine ring. The interplanar angle between the mean planes of the pyridine and imidazolidine rings is 89.41 (5)°. The methyl group is in a trans position with respect to the pyridine N atom. In the crystal, the molecules are arranged in zigzag layers parallel to the b axis. The molecules within the layers are interconnected by strong O—H⋯N and weak N—H⋯O hydrogen bonds; the former take place between OH groups and amine N atoms and the latter between the amine N atom and the carbonyl O atom. In addition, C—H⋯O interactions are also present.

Crystal structure of (E)-2-{[(4-anilinophen­yl)imino]­meth­yl}phenol

The title compound crystallized with two independent molecules (A and B) in the asymmetric unit, which differ essentially in the orientation of the terminal aminophenyl ring with respect to the central benzene ring. In the crystal, molecules are linked via N—H⋯O hydrogen bonds forming –A-B–A–B– zigzag chains propagating along [010].

cyclo-Tetra­kis(μ-3-acetyl-4-methyl-1H-pyrazole-5-carboxyl­ato-κ4N2,O3:N1,O5)tetra­kis[aqua­copper(II)] tetra­deca­hydrate

The title compound, [Cu4(C7H6N2O3)4(H2O)4]·14H2O, a tetranuclear [2 × 2] grid-type complex with S4 symmetry, contains four CuII atoms which are bridged by four pyrazolecarboxylate ligand anions and are additionally bonded to a water molecule. Each CuII atom is coordinated by two O atoms of the carboxylate and acetyl groups, two pyrazole N atoms of doubly deprotonated 3-acetyl-4-methyl-1H-pyrazole-5-carboxylic acid and one O atom of a water molecule. The geometry at each CuII atom is distorted square-pyramidal, with the two N and two O atoms in the equatorial plane and O atoms in the axial positions. O—H⋯O hydrogen-bonding interactions additionally stabilize the structure. One of the uncoordinated water molecules shows half-occupancy.

2-Hydroxy­imino-N′-[1-(2-pyrid­yl)ethyl­idene]propanohydrazide

The title compound, C10H12N4O2, features an intramolecular N—H⋯N hydrogen bond formed between the imine NH and oxime N atoms. The oxime group and the amide C=O bond are anti to each other. In the crystal, molecules are connected by O—H⋯O hydrogen bonds into supramolecular zigzag chains along the c axis.

Preparation and Crystal Structure of a Mixed Metal Assembly [Ni(phen)3][Cu(H-1pap)]2(NO3) · 8 H2O Featuring Octahedral Cationic and Square-planar Anionic Modules

Abstract The new mixed metal assembly [Ni(phen)3][Cu(H-1pap)]2(NO3 ) · 8 H2O (2) (H2pap = CH3- C(=NO H)-C(O )-NH-(CH2)3-NH-C(O )-C(=NOH)-CH3) was obtained by co-crystallisation of [Li(H2O)4][Cu(H-1pap)] · 2 H2O (1) and tris(1,10-phenanthroline)nickel(II) nitrate and studied by means of X-ray crystallography (triclinic, space group P1, a = 13.471(3), b = 13.641(3), c = 15.401(3) Å, α = 108.21(3), β = 97.73(3), γ = 107.74(3)°, V = 2476.6(9) Å , Z = 2 ,R1 = 0.0677 for 4672 unique reflections with I > 2σ(I)). The assembly indicates a network structure and consists of isolated cationic and anionic modules (octahedral [Ni(phen)3]2+ and square-planar [Cu(H-1pap)]-), non-coordinated nitrate anions and solvating water molecules. The elements of the crystal structure are linked by interactions of different types: by an extended system of H bonds, stacking interactions between aromatic rings, long apical Cu-N contacts and specific π-π interaction between a deprotonated oxime group of the complex anion and a phenanthroline ligand

Conformational analysis of pyruvyl-L-alanine oxime

Abstract The conformation of pyruvyl- l -alanine oxime in DMSO solution has been studied by means of 1H and 13C NMR spectroscopy and the torsion angle φ proved to be equal to −160 ± 5°. The geometrical parameters and calculated MNDO values of ΔH for the observed conformer, for those seen in the crystal solid and for the most favoured calculated conformation are compared.

Crystal structure of 2-aza­niumyl-3-bromo-6-oxo-5,6-di­hydro­pyrido[1,2-a]quinoxalin-11-ium dibromide

The title salt, C12H10BrN3O2+·2Br−, was synthesized from the reaction of N 1,N 4-bis(pyridin-2-ylmethylidene)benzene-1,4-diamine and bromine in a methanol solution. All non-H atoms of the 2-azaniumyl-3-bromo-6-oxo-5,6-dihydropyrido[1,2-a]quinoxalin-11-ium cation are nearly coplanar, the maximum deviation being 0.114 (4) Å. In the crystal, the cations and anions are linked through N—H⋯Br hydrogen bonds and weak C—H⋯Br interactions, forming a three-dimensional supramolecular architecture. A short Br⋯Br contact [3.3088 (9) Å] is observed in the crystal.

Crystal structure of meso-tetra­kis­(4-nitro­phen­yl)porphyrin nitro­benzene disolvate

The porphyrin core of the title centrosymmetric compound, C44H26N8O8·2C6H5NO2, is approximately planar, the maximum deviation being 0.069 (3) Å. The planes of the benzene rings of the nitrophenyl substituents are almost perpendicular to the porphyrin mean plane, making dihedral angles of 73.89 (9) and 89.24 (9)°. The two pyrrole ring H atoms are equally disordered over the four pyrrole ring N atoms. In the crystal, weak C—H⋯O and C—H⋯N hydrogen bonds link the porphyrin molecules into a three-dimensional supramolecular network. The nitrobenzene solvent molecules are linked by weak C—H⋯O hydrogen bonds into supramolecular chains propagating along the a-axis direction.

(3-Acetyl-4-methyl-1H-pyrazol-1-ide-5-carboxyl-ato)bis-(1,10-phenanthroline)nickel(II) 3.5-hydrate.

The title compound, [Ni(C7H6N2O3)(C12H8N2)2]·3.5H2O, crystallizes as a neutral mononuclear complex with 3.5 solvent water molecules. One of the water molecules lies on an inversion centre, so that its H atoms are disordered over two sites. The coordination environment of NiII has a slightly distorted octahedral geometry, which is formed by one O and five N atoms belonging to the N,O-chelating pyrazol-1-ide-5-carboxylate and two N,N′-chelating phenanthroline molecules. In the crystal, O—H⋯O, N—H⋯O and O—H⋯N hydrogen bonds involving the solvent water molecules and pyrazole-5-carboxylate ligands form layers parallel to the ab plane. These layers are linked further via weak π–π interactions between two adjacent phenanthroline molecules, with centroid-to-centroid distances in the range 3.886 (2)–4.018 (1) Å, together with C—H⋯π contacts, forming a three-dimensional network.