Filip Kielar

Oxidative Decolorization of Acid Azo Dyes by a Mn Oxide Containing Waste

A Mn oxide containing mine tailings, generated in the Kalahari Mn fields, has been shown to oxidatively breakdown acid azo dyes acid orange (AO) 7, acid red 88, acid red 151 and acid yellow 36 but not acid yellow 9. The total reducible Mn content of the tailings is 33%, of which 3% is hydroquinone extractable and thus easily reducible. The net oxidation state of the Mn within the tailings is 3+. Decolorization of AO 7 by the Mn tailings increases with decreasing pH. The decolorization mechanism is initiated on the hydroxyl group of AO 7 and proceeds via successive electron transfers from the dye molecule to the oxide surface resulting in the asymmetric cleavage of the azo bond. The reaction products have been identified as 1,2-naphthoquinone, 4-hydroxybenzenesulfonate, and coupling products involving 1,2-naphthoquinone and benzenesulfonate radicals. The AO 7: Mn(III) reaction stoichiometry has been tentatively calculated to be 1:3. The reaction shows longevity with 95% decolorization still observed after 60 days of dye replenishment. Further breakdown of 1,2-naphthoquinone and 4-hydroxybenzenesulfonate was not observed, thus these compounds are considered to be the terminal reaction products of the AO 7- Mn tailings reaction.

Crystal structure of a mixed-ligand terbium(III) coordination polymer containing oxalate and formate ligands, having a three-dimensional fcu topology

The crystal structure of catena-[(μ 3-formato)(μ 4-oxalato)terbium(III)] features a three-dimensional 12-connected fcu topology with point symbol (324.436.56), exhibiting thermal stability up to 623 K and strong green photoluminescence in the solid state at room temperature.

Novel aminoalkyl tris-cyclometalated iridium complexes as cellular stains

Herein we report the synthesis and investigation of the properties of two tris-cyclometalated luminescent iridium complexes. These complexes are the simple derivatives of fac-[Ir(ppy)3] bearing amino alkyl groups on one of the phenylpyridine rings. The complexes are highly emissive and exhibit structured emission peaks in aqueous solution while having only broad unstructured emission in organic solvents. The complexes have been shown to be taken up by NIH-3T3 and PC3 cells, where they localize in the lysosomes and remain emissive with lifetimes in the microsecond domain.

Crystal structures of (E)-N′-(2-hy­droxy-5-methyl­benzyl­idene)isonicotinohydrazide and (E)-N′-(5-fluoro-2-hy­droxy­benzyl­idene)isonicotinohydrazide

The title isonicotinohydrazides adopt an E conformation about the C=N bonds and in each molecule there is an intramolecular O—H⋯N hydrogen bond, forming an S(6) ring motif. In the crystals of both compounds, zigzag chains are formed via N—H⋯N hydrogen bonds, in the [10] the first compound and [010] for the other.

Temperature dependent 3D structures of lanthanide coordination polymers based on dicarboxylate mixed ligands

Fourteen three-dimensional (3D) lanthanide coordination polymers (CPs) with dicarboxylate mixed ligands, [Ln(fum)1.5(H2O)2]·0.5(H2bdc)·H2O (Ln = Sm (1), Tb (2)), [Ln2(fum)2(bdc)(H2O)4]·2H2O (Ln = Sm (3), Eu (4), Tb (5), Er (6)), [Ln(fum)0.5(bdc)] (Ln = Sm (7), Eu (8), Tb (9), Er (10)), and [Ln2(bdc)2(ox)(H2O)4]·0.7H2O (Ln = Sm (11), Gd (12), Tb (13), Dy (14)), have been synthesized hydrothermally from the self-assembly of lanthanide(III) ions (Ln3+), fumaric acid (H2fum), and terephthalic acid (H2bdc) in the presence of potassium hydroxide at different temperatures. The compounds fall into four classes. Compounds 1 and 2 were isolated from hydrothermal reactions performed at a relatively low temperature of 100 °C and found to crystallize in the triclinic space group P. The 3D framework is assembled from 2D layers of [Ln(fum)(H2O)2] units pillared by the chelating fum ligands and has 1D rhombic channels templated by H2bdc and lattice H2O molecules. The framework presents a binodal (4,5)-connected tcs topology with the point symbol (44·62)(44·66). Raising the reaction temperature to 140 °C resulted in the formation of compounds 3–6. These materials crystallize in the monoclinic system with the polar space group P21 and feature a 3D network constructed from dinuclear {Ln2(OCO)6(H2O)4} units interlinked by fum and bdc ligands, showing a uninodal 6-connected two-fold interpenetrated pcu topology. The small channels of the framework are occupied by lattice H2O molecules. Further increase of the reaction temperature to 160 °C gave rise to the formation of compounds 7–10, crystallizing in the orthorhombic space group Pbca. The 3D framework is generated from 2D corrugated sheets of [Ln(fum)]2+ bound by bdc ligands and contains no intercalated H2O molecules in the lattice. The framework possesses a trinodal (4,6,7)-connected net with the point symbol (42·64)2(46·68·8)(412·69)2. Finally, compounds 11–14 contained an in situ generated oxalate (ox) ligand formed under hydrothermal conditions conducted at a high reaction temperature of 180 °C. These compounds crystallize in the monoclinic space group P21/c and possess a 3D open framework consisting of a dinuclear [Ln2(ox)(H2O)4]2+ unit linked by bridging bdc ligands and has small void channels occupied by lattice H2O molecules. The frameworks were topologically simplified as a binodal (4,5)-connected tcj/hc net with a total point symbol of (42·52·72)(42·53·75). In the solid state at room temperature, the Tb (2, 5, 9, and 13) and Eu (4 and 8) compounds emit green and red light, respectively.

Crystal structure of (E)-N′-(3-fluoro-2-hy­droxy­benzyl­idene)isonicotinohydrazide

The title isonicotinohydrazide derivative is planar, with an r.m.s. deviation for the fitted non-H atoms of 0.062 Å, and an intramolecular O—H⋯N hydrogen bond with an S(6) ring motif. In the crystal, molecules are linked by N—H⋯N and C—H⋯N hydrogen bonds forming chains propagating along the a-axis direction.

A novel one-dimensional double-chain-like ZnII coordination polymer: poly[bis­(1-benzyl-1H-imidazole-κN3)tris­(μ-cyanido-κ2C:N)(cyanido-κC)disilver(I)zinc(II)]

One of most interesting systems of coordination polymers constructed from the first-row transition metals is the porous ZnII coordination polymer system, but the numbers of such polymers containing N-donor linkers are still limited. The title double-chain-like ZnII coordination polymer, [Ag2Zn(CN)4(C10H10N2)2]n, presents a one-dimensional linear coordination polymer structure in which ZnII ions are linked by bridging anionic dicyanidoargentate(I) units along the crystallographic b axis and each ZnII ion is additionally coordinated by a terminal dicyanidoargentate(I) unit and two terminal 1-benzyl-1H-imidazole (BZI) ligands, giving a five-coordinated ZnII ion. Interestingly, there are strong intermolecular AgI...AgI interactions between terminal and bridging dicyanidoargentate(I) units and C-H...π interactions between the phenyl rings of BZI ligands of adjacent one-dimensional linear chains, providing a one-dimensional linear double-chain-like structure. The supramolecular three-dimensional framework is stabilized by C-H...π interactions between the phenyl rings of BZI ligands and by AgI...AgI interactions between adjacent double chains. The photoluminescence properties have been studied.

Crystal structure of trans-bis­{4-bromo-N-[(pyridin-2-yl)­methyl­idene]aniline-κ2N,N′}di­chlorido­ruthenium(II)

The RuII atom in the title complex is surrounded by a distorted Cl2N4 coordination set. In the crystal structure, adjacent complex molecules are connected through C—H⋯Cl hydrogen-bonding interactions into a layered arrangement parallel to (100). Additional C—H⋯Br hydrogen-bonding interactions along with π–π stacking interactions complete a three-dimensional supramolecular network.