The synthesis of the [Fe(Phen)3](iso-Bu2PS2)2 Complex. The crystal structures of [Fe(Phen)3](iso-Bu2PS2)2 · 5H2O and disulfan {iso-Bu2P(S)S}2

The complex [Fe(Phen)₃][iso-Bu₂PS₂)₂ (I) was synthesized and the single crystals of [Fe(Phen)₃](iso-Bu₂PS₂)₂ · 5H₂O (II) were grown. The disulfan {iso-Bu₂P(S)S}₂ (III) was isolated. Compound II consists of the complex cations [Fe(Phen)₃]²⁺, the outer-sphere anions iso-Bu₂PS ₂ ^? , and the molecules of water of crystallization. The coordination polyhedron of the Fe atom is a distorted N₆ octahedron. Complex I is diamagnetic, and thus, the full spin of the Fe²⁺ ion S = 0. The structure of III is built of the molecules containing the S-S bridge 2.061(1) Å in length.     

Mixed-ligand complex compounds [Pb(Phen)×{(iso-C4H9)2PS2}2] and [Pb(2,2′-Bipy){(iso-C4H9)2PS2}2] and formation of supramolecular assemblies in their crystal structures

Mixed-ligand complex compounds [Pb(Phen)(i-Bu₂PS₂)]₂ (I) and [Pb(2,2′-Bipy)(i-Bu₂PS₂)]₂ (II) were synthesized. Their structures were determined from X-ray diffraction data (X8 APEX diffractometer, MoK _α radiation, 6392 _Fhkl , R = 0.0233 for I and 3937 F _hkl , R = 0.0252 for II). Crystals I are triclinic: a = 10.2662(3) Å, b = 12.3037(2) Å, c = 14.8444(4) Å; α = 92.054(1)°, β = 103.473(1)°, γ = 105.561(1)°, V = 1746.89(8) ų, Z = 2, ρ_calc = 1.532 g/cm³, space group P . Crystals II are monoclinic: a = 9.3462(3) Å, b = 26.3310(12) Å, c = 28.5345(13) Å; β = 96.436(1)°, V = 6977.9(5) ų, Z = 8, ρ_calc = 1.489 g/cm³, space group P2₁/n. The structures are built from mononuclear molecules. In both structures, the intermolecular contacts between the Pb and S atoms of the neighboring mononuclear molecules form supramolecular assemblies involving two molecules. The environment of the Pb atoms in the assemblies is a pentagonal bipyramid, N₂S₄₊₁. The assemblies are joined into ribbons by π-π interactions of the Phen rings in I and C…C short contacts between the pyridine rings in II. Original Russian Text Copyright ? 2008 by R. F. Klevtsova, E. A. Sankova, T. E. Kokina, L. A. Glinskaya, and S. V. Larionov __________ Translated from Zhurnal Strukturnoi Khimii, Vol. 49, No. 1, pp. 123–131, January–February, 2008.     

Genotoxic Evaluation of Fe3O4 Nanoparticles in Different Three Barley (Hordeum vulgare L.) Genotypes to Explore the Stress-Resistant Molecules

Sustainable agricultural practices are still essential due to soil degradation and crop losses. Recently, the relationship between plants and nanoparticles (NPs) attracted scientists’ attention, especially for applications in agricultural production as nanonutrition. Therefore, the present research was carried out to investigate the effect of Fe₃O₄ NPs at low concentrations (0, 1, 10, and 20 mg/L) on three genotypes of barley (Hordeum vulgare L.) seedlings grown in hydroponic conditions. Significant increases in seedling growth, enhanced chlorophyll quality and quantity, and two miRNA expression levels were observed. Additionally, increased genotoxicity was observed in seedlings grown with NPs. Generally, Fe₃O₄ NPs at low concentrations could be successfully used as nanonutrition for increasing barley photosynthetic efficiency with consequently enhanced yield. These results are important for a better understanding of the potential impact of Fe₃O₄ NPs at low concentrations in agricultural crops and the potential of these NPs as nanonutrition for barley growth and yield enhancement. Future studies are needed to investigate the effect of these NPs on the expression of resistance-related genes and chlorophyll synthesis-related gene expression in treated barley seedlings.     

Host-[2]rotaxane: advantage of converging functional groups for guest recognition

A host-[2]rotaxane was constructed by converting a diaminophenylcalix[4]arene into a [2]rotaxane using the DCC-rotaxane method (Zehnder, D.; Smithrud, D. B. Org. Lett. 2001, 16, 2485-2486). N-Ac-Arg groups were attached to the dibenzo-24-crown-8 ring of the rotaxane to provide a convergent functional group. To demonstrate the advantage provided by the rotaxane architecture for recognition of guests that contain a variety of functional groups, association constants (K(A)) for N-Ac-Trp, indole, N-Ac-Gly, fluorescein, 1-(dimethylamino)-5-naphthalenesulfonate, and pyrene bound to the [2]rotaxane were determined by performing (1)H NMR and fluorescence spectroscopic experiments. The host-[2]rotaxane had the highest affinity for fluorescein with a K(A) = 4.6 x 10(6) M(-)(1) in a 98/2 buffer (1 mM phosphate, pH 7)/DMSO solution. A comparison of K(A) values demonstrates that both the aromatic pocket and ring of the host-[2]rotaxane contribute binding free energy for complexation. Association constants were also derived for the same guests bound to the diaminophenylcalix[4]arene and to a diphenylcalix[4]arene that contained arginine residues displayed in a nonconvergent fashion. The host-[2]rotaxane provides higher affinity and specificity for most guests than the host with divergent N-Ac-Arg groups of the one that only has an aromatic pocket. For example, the K(A) for the complex of the host-[2]rotaxane and fluorescein in the DMSO/water mixture is more than 2 orders of magnitude greater than association constants derived for the other hosts.     

Electrochemical ultramicromethods of analysis

Summary Electroanalytical methods have been used under the conditions of chemical experimentation on the ultramicroscale. Capillary cells for coulometric titration with detection of equivalence points by various methods are described. A design is suggested for a reference palladium-hydrogen microelectrode with its own gas supply and a technique is described for measuring p_H by the quinhydrone method with the use of an insignificant fraction of the small test volume of solution. Coulometric ultramicrodeterminations based on oxidation-reduction, precipitation and complex formation have been carried out. By the suggested experimental technique, Zn, In and Ni have been determined in small samples of semiconductor alloys and cosmic particles.

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Zusammenfassung Elektrochemische Analysenmothoden wurden, im Ultramikromaßstab angewendet. Kapillarzellen für coulometrische Titrationen mit verschiedenen Methoden der Endpunktanzeige wurden beschrieben. Eine Palladium-Wasserstoff-Bezugselektrode mit eigener Gasversorgung wurde angegeben und ein Verfahren beschrieben, um p_H-Bestimmungen nach der Chinhydronmethode in einem ganz kleinen Teil einer Probelösung auszuführen. Coulometrische Ultramikrobestimmungen auf der Grundlage von Redoxvorgängen, von Fällungsreaktionen und von Komplexbildungen wurden ausgearbeitet. Mit Hilfe der empfohlenen Arbeitsweise wurden Zn, In und Ni in kleinen Proben von Halbleiterlegierungen und kosmischen Partikeln bestimmt.

     

Crystal and molecular structures of Ni[(iso-C4H9)2PS2]2 and Pd[(iso-C4H9)2PS2]2 chelates

Crystal structures of chelate compounds Ni[(iso-C₄H₉)₂PS₂]₂ (I) and Pd[(iso-C₄H₉)₂PS₂]₂ (II) have been determined by X-ray diffraction: diffractometer X8-APEX, MoK _α∔ -radiation, 1048 F _hkl , R = 0.0544 for I and CAD-4 diffractometer, MoK _α∔ -radiation, 1283 F _hkl , R = 0.0347 for II. The crystals are rhombic: a = 12.921(5) Å, b = 17.094(5) Å, c = 22.971(5) Å; V = 5074(3) ų, Z = 8, calc = 1.250 g/cm³, space group Pbca for I and a = 13.312(3) Å, b = 16.130(7) Å, c = 23.171(5) Å; V = 4975(3) ų, Z = 8, ρ_calc = 1. 208 g/cm³, space group Pbca for II. The structures of I and II are formed by discrete mononuclear molecules. Coordination cores MS₄ (M = Ni, Pd) approach planar square configurations. Original Russian Text Copyright ? 2005 by L. A. Glinskaya, T. G. Leonova, T. E. Kokina, R. F. Klevtsova, and S. V. Larionov __________ Translated from Zhurnal Strukturnoi Khimii, Vol. 46, No. 4, pp. 715–720, July–August, 2005.     

Dimeric ensembles in the crystal structures of mixed-ligand coordination compounds ML(<Emphasis Type="Italic">i</Emphasis>-Bu<Subscript>2</Subscript>PS<Subscript>2</Subscript>)<Subscript>2</Subscript> (M = Zn,Cd, Mn,Co, Ni; L = Phen, 2,2′-Bipy)

Single crystals of a mononuclear mixed-ligand complex [Mn(Phen)(i-Bu₂PS₂)₂] were grown and used for X-ray diffraction structural study of the material (diffractometer CAD-4, MoK _α -radiation, 1205 F _hkl , R = 0.0351). The crystals are monoclinic: a = 15.602(2) Å, b = 20.914(3) Å, c = 11.419(2) Å; β = 111.36(1)°, V = 3470.1(9) ų, Z = 4, ρ(calc) = 1.251 g/cm³, space group P2₁/c. Coordination polyhedron of Mn is a distorted octahedron N₂S₄. Molecular and crystal structures of mixed-ligand coordination compounds ML(i-Bu₂PS₂)₂ (M= Zn, Cd, Mn, Co, Ni; L = Phen, 2,2′-Bipy) are considered on the basis of XRD data (automated diffractometers CAD-4 and X8-APEX). The analysis of intermolecular distances in the structures of ten mixed-ligand coordination compounds revealed in nine of them the presence of short contacts made by carbon atoms of the N-heterocycles. These contacts correspond to π-π interactions of Phen or 2,2′-Bipy molecules of two neighboring complexes giving rise to dimeric molecular ensembles.     

Synthesis and structure of Cu(II) and Pd(II) coordination compounds with chiral α-thiooxime,a derivative of natural terpenoid (−)-α-pinene

The paramagnetic complex Cu(HL)Cl₂(I) (μ_eff = 1.88 μ_B) and the diamagnetic complex Pd(HL)Cl₂(II) with chiral α-thiooxime, a derivative of natural terpenoid (?)-α-pinene (HL), were synthesized. The crystal structures of these complexes were determined from single-crystal X-ray diffraction data (X8 APEX diffractometer, MoK _α radiation, 2975 F _hkl , R = 0.0258 for I and 3270 F _hkl , R = 0.0222 for II). The crystals of complex I are monoclinic, a = 9.3376(3) Å, b = 6.8619(2) Å, c = 14.6540(5) Å, β = 97.814(1)°, V = 930.22(5) ų, Z = 2, ρ_calc = 1.513 g/cm³, space group P2₁. The crystals of complex II are orthorhombic, a = 7.0084(6) Å, b = 9.2113(9) Å, c = 29.081(3) Å, V = 1877.4(3) ų, Z = 4, ρ_calc = 1.651 g/cm³, space group P2₁2₁2₁. The structures are composed of mononuclear molecules. The coordination cores MNSCl₂ (M = Cu, Pd) are tetrahedrally distorted squares. According to NMR data, complex II has a similar structure in a CDCl₃ solution. The intermolecular contacts in structure I generate supramolecular polymeric ribbons lying parallel to axis b. No short intermolecular contacts are present in complex II.     

Synthesis and structure of the mononuclear octacoordinate complex [Pb(Phen)2( iso -Bu2PS2)2] and polynuclear complex [Pb(4,4′-Bipy)( iso -Bu2PS2)2] n : Formation of ribbons and supramolecular assemblies in their crystalline structures

Heteroligand complexes [Pb(Phen)₂(iso-Bu₂PS₂)₂] (I) and [Pb(4,4′-Bipy(iso-Bu₂PS₂)₂] _n (II) were synthesized, and their crystal structures were determined. The crystals of complex I are monoclinic: a = 17.2011(9) ?, b = 14.1695(7) ?, c = 19.8727(12) ?; β = 115.644(1)°, V = 4366.5(4) ?³, Z = 4, ρ_calcd = 1.500 g/cm³, space group C2/c. The crystals of complex II are triclinic: a = 11.9283(2)?, b = 12.3814(2) ?, c = 14.0917(3) ?; α = 74.705(1)°, β = 87.240(1)°, γ = 61.448(1)°, V = 1755.86(6) ?³, Z = 2, ρ_calcd = 1.479 g/cm³, space group P . The structure of complex I consists of mononuclear molecules. The coordination polyhedron of the Pb atom is a distorted tetragonal antiprism N₄S₄ formed by the bidentate chelating ligands Phen and iso-Bu₂PS₂⁻. Continuous zigzag ribbons along the c axis are formed through contacts of the peripheral atoms of the Phen molecules of the adjacent complexes. Polynuclear complex II has a chain structure. The coordination polyhedron of the Pb atom is a distorted octahedron N₂S₄ formed by the bidentate chelating iso-Bu₂PS₂⁻ ligands and bidentate bridging 4,4′-Bipy molecules. Short intermolecular contacts between the Pb and S atoms of the adjacent chains in structure II result in the formation of supramolecular two-chain assemblies as volume columns parallel to the b axis. The environment of the Pb atoms in the assembly is formed by pentagonal bipyramids N₂S_{4 + 1}. Original Russian Text ? S.V. Larionov, R.F. Klevtsova, E.A. Sankova, L.A. Glinskaya, T.E. Kokina, 2008, published in Zhurnal Neorganicheskoi Khimii, 2008, Vol. 53, No. 9, pp. 1516–1524.     

Synthesis and properties of the Cu(II) complexes with chiral bis{( E )-[(1 S ,4 R )-Δ7,8-1-amino-2- para -menthalidene]aminohydroxy}methane (L — a derivative of natural terpenoid ( R )-(+)-limonene). Crystal structure of the [Cu(L)(μ-Cl)CuCl3] · iso -PrOH solvate

The Cu₂LCl₄ complex (I) with chiral bis{(E)-[(1S,4R)-Δ^7,8-1-amino-2-para-menthalidene]aminohydroxy} methane (L — a derivative of natural monoterpenoid (R)-(+)-limonene) is synthesized. The crystal structure of the solvate of complex I[Cu(L)(μ-Cl)CuCl₃] · iso-PrOH (II) is determined by X-ray diffraction analysis. Structure II is based on molecules of the [Cu(L)(μ-Cl)CuCl₃] binuclear complexes in which L is the tetradentate cycleforming ligand. One Cl atom manifests the bridging function. The CuN₄ Cl coordination unit is a square pyramid, and CuCl₄ is a distorted tetrahedron. The iso-PrOH molecules are localized in cavities between the layers of structure II. The μ_eff value for complex I is 2.56 μB and indicates the absence of an appreciable interaction between the Cu²⁺ ions in the Cu(II)-Cl-Cu(II) exchange cluster. The compound CuLCl₂· H₂O (III) is synthesized. The μ_eff value for compound III is 1.6 μB. Complexes I and III are studied by EPR and IR spectroscopy. Original Russian Text ? T.E. Kokina, L.A. Glinskaya, R.F. Klevtsova, E.G. Boguslavskii, L.A. Sheludyakova, S.N. Bisyaev, A.V. Tkachev, S.V. Larionov, 2009, published in Koordinatsionnaya Khimiya, 2009, Vol. 35, No. 3, pp. 202–211.