Vadim A. Pavlenko

Direct synthesis and crystal structure of the polymeric thiocyanate complexes of copper(I)

Abstract The compounds Cu(SCN)·CH3CN (1) and [(CH3)3NH]+[Cu2(SCN)3]− (2) have been synthesized using a direct method of interaction and characterized by X-ray crystallography. The planar Cu2S2 units with the copper-copper distances 3.095 (1) and 2.972 A (2) form the basis of both structures. Complex 1 consists of the infinite puckered layers with the interlayer distance 6.657 A. The three-dimensional polymeric anion [Cu2(SCN)3]− in compound 2 comprises two crystallographically independent copper(I) atoms and two bridging thiocyanate groups with different coordinations.

Bis(3,5-dimethyl-1H-pyrazolyl)selenide – a new bidentate bent connector for preparation of 1D and 2D co-ordination polymers

The synthesis and description of eight polymeric complexes formed by transition metals with the bifurcated ligand bis(3,5-dimethyl-1H-pyrazolyl)selenide are discussed together with X-ray crystal analysis as well as variable temperature magnetic susceptibility and characterization by Mössbauer spectroscopy. Preferable types of binding patterns of the ligand were determined, which include a variation of the bridging modes (cis- and trans-) and of the separation length, where the latter parameter together with bending of the ligand molecule were found to be dependent on the type of co-ordination geometry of the central atom and the nature of the anion. A strategy for increasing the structure dimensionality was explored using bridging properties of anions yielding 2D hybrid organic-inorganic polymers.

catena-Poly[[copper(II)-bis[μ-bis(3,5-dimethyl-1H-pyrazol-4-yl) selenide]] bis(perchlorate)]

In the title compound, {[Cu(C10H14N4Se)2](ClO4)2}n, the CuII ion is located on a twofold rotation axis and has a tetragonally distorted square-planar geometry constituted by four N atoms. A pair of bis(3,5-dimethyl-1H-pyrazol-4-yl) selenide (L) ligands bridges the copper centers into a polymeric chain extending along [001]. The perchlorate anions are involved in intermolecular N—H⋯O hydrogen bonding, which links the chains into layers parallel to the bc plane.

catena-Poly[[[aqua­copper(II)]-bis­[μ-bis­(3,5-dimethyl-1H-pyrazol-4-yl) selenide-κ2N2:N2′]] dichloride monohydrate]

In the title compound, {[Cu(C10H14N4Se)2(H2O)]Cl2·H2O}n, the CuII ion, lying on a twofold rotation axis, has a square-pyramidal geometry constituted by four N atoms of pyrazolyl groups in the basal plane and an apical O atom of a water molecule. A pair of bis(3,5-dimethyl-1H-pyrazol-4-yl) selenide ligands bridge the Cu centers into a polymeric double-chain extending along [001]. The chloride anions are involved in intermolecular N—H⋯Cl and O—H⋯Cl hydrogen bonds, which link the chains into a three-dimensional network.

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.

catena-Poly[[[aqua­copper(II)]bis­[μ-bis(3,5-dimethyl-1H-pyrazol-4-yl) selenide]] bis­(tetra­fluorido­borate) bis­(triphenyl­phosphine oxide) monohydrate]

The title compound, {[Cu(C10H14N4Se)2(H2O)](BF4)2·2C18H15PO·H2O}n, has a polymeric structure where each CuII ion adopts a square-pyramidal coordination constituted by four N atoms of pyrazole moieties in the equatorial plane and an axial O atom of a water molecule. A pair of bis(3,5-dimethyl-1H-pyrazol-4-yl) selenide ligands bridges the CuII centres into a chain extending along the c axis. The water molecules, anions and triphenylphosphine oxide molecules are involved in intermolecular hydrogen bonding, which links the chains into a three-dimensional network.

(μ-3-Acetyl-5-carboxyl­ato-4-methyl­pyrazolido-1:2κ4N2,O3:N1,O5)-μ-chlorido-tetra­pyridine-1κ2N,2κ2N-chlorido-1κCl-dicopper(II) propan-2-ol solvate

The title compound, [Cu2(C7H6N2O3)Cl2(C5H5N)4]·C3H8O, is a binuclear pyrazolate complex, in which the two CuII atoms have different coordination numbers and are connected by a bridging Cl atom. One CuII atom has a distorted square-pyramidal coordination environment formed by two pyridine N atoms, one bridging Cl atom and an N,O-chelating pyrazolate ligand. The other CuII atom adopts an octahedral geometry defined by two pyridine N atoms at the axial positions, two Cl atoms and the coordinated pyrazolate ligand in the equatorial plane. An O—H⋯O hydrogen bond connects the complex molecules and propan-2-ol solvent molecules into pairs. These pairs form columns along the a axis.

[Di­aqua­sesqui(nitrato-κO)hemi(perchlorato-κO)copper(II)]-μ-{bis­[5-methyl-3-(pyridin-2-yl)-1H-pyrazol-4-yl] selenide}-[tri­aqua­(perchlorato-κO)copper(II)] nitrate monohydrate

In the binuclear title complex, [Cu2(ClO4)1.5(NO3)1.5(C18H16N6Se)(H2O)5]NO3·H2O, both CuII ions are hexacoordinated by O and N atoms, thus forming axially elongated CuO4N2 octahedra. The equatorial plane of each octahedron is formed by one chelating pyrazole–pyridine fragment of the organic ligand and two water molecules. The axial positions in one octahedron are occupied by a water molecule and a monodentately coordinated perchlorate anion, while those in the other are occupied by a nitrate anion and a disordered perchlorate/nitrate anion with equal site occupancy. The pyrazole–pyridine units of the organic selenide are trans-oriented to each other with a C—Se—C angle of 96.01 (14)°. In the crystal, uncoordinated nitrate anions and the coordinating water molecules are involved in O—H⋯O and N—H⋯O hydrogen bonds, forming a bridge between the pyrazole group and the coordinating water molecules. Further O—H⋯O hydrogen bonds between the complex molecules and a π–π stacking interaction with a centroid–centroid distance of 3.834 (4) Å are also observed.

Bis{4-[(3,5-dimethyl-1H-pyrazol-4-yl)selan­yl]-3,5-dimethyl-1H-pyrazol-2-ium} chloride monohydrate

In the title compound, 2C10H15N4Se+·Cl−·OH−, a singly protonated molecule of the organic selenide participates in hydrogen bonding with neighboring molecules, forming zigzag chains along [001]. The molecule adapts a cis bridging mode with a C—Se—C angle of 102.13 (15)°. π–π stacking interactions are observed between the closest pyrazole rings of neighboring chains [centroid–centroid distance = 3.888 (1) Å] and hydrogen bonding occurs through bridging chloride anions and hydroxide groups. Additionally, O—H⋯Cl hydrogen bonds are formed.

3,5-Dimethyl-4-nitroso-1H-pyrazole

In the unit cell of the title compound, C5H7N3O, there are two conformers (A and B) which differ in the position of the oxime group with respect to the protonated pyrazole nitrogen (trans in the A conformer and cis in the B conformer) and in the geometric parameters. The oxime group exists in the nitroso form in both conformers. In the crystal, molecules are linked by intermolecular N—H⋯O and N—H⋯N hydrogen bonds into zigzag-like chains along the b axis.