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1.
Marek Daszkiewicz Zbigniew Staszak Adam Pietraszko Wiesława Bronowska Maria Cieślak-Golonka 《Structural chemistry》2006,17(6):599-608
Two polymeric complexes: catena(μ-CrO4-O,O′)[Co(HIm)3H2O] (1) and catena(μ-CrO4-O,O′)[Co0.43Ni0.57(HIm)3H2O] (2) (where HIm=imidazole) with a cis-bridging coordination mode of the CrO4
2− anion have been synthesized and characterized by X-ray and spectroscopic methods. These crystals were isolated from nine
systems of varying reagent molar ratios and three excluding anions: Cl−, NO3
− and SO4
2− exclusively as mer [M(HIm)3O3]-type isomers. The unit cell of these isostructural complexes (monoclinic crystal system P21
/n) contains two independent helixes, left- and right handed, stabilized by intrahelical and interhelical hydrogen bonding and
π–π interaction between pairs of the imidazole rings from neighbouring helixes. The Raman spectra at 77 K of 1 and 2 deconvoluted into lorentzian components revealed the block-type polymeric structure of the complexes. Moreover, the solution
studies at millimolar concentrations of 1 and 2 indicated their complete decomposition in water. Four K electronic spectral analysis of the crystals (band deconvolution
into gaussian components) enhanced with the data obtained in the polarized light allowed for assignment of the bands to the
respective d–d transition (D4h symmetry). It was found that the metallic centres are independently absorbing species, which supports the suggestion of a
block-type structure of the polymers. The respective crystal field parameters for Co and Ni were calculated. 相似文献
2.
Maciejewska Gabriela Cieślak-Golonka Maria Staszak Zbigniew Szeląg Adam 《Transition Metal Chemistry》2002,27(6):587-593
Six new heteropolynuclear chromium(III)/vanadium(V) complexes with natural ligands: glycine, glutaminic, nicotinic and asparginic acids, have been isolated and physicochemically characterised. The complexes have been analysed using spectroscopic (diffuse reflectance u.v.–vis., i.r.), magnetic methods and by FAB mass spectra. Spectral analyses with the digital filter and band deconvolution methods are presented. Additionally, preliminary toxicity studies have been performed. 相似文献
3.
The influence of solvents on the electronic absorption spectra of chromium (III) complexes was investigated. The dependence of the crystal field parameter Dq on dielectric constant as well as Gutmann donor number DN of solvent was found and described. By using the proposed model, unknown in the literature donor numbers for a few alcohols were estimated. 相似文献
4.
Agnieszka Wojciechowska Adam Pietraszko Wieslawa Bronowska Zbigniew Staszak Julia Jezierska Maria Cieślak-Golonka 《Polyhedron》2010
A novel copper(II) chromate complex of the formula [Cu(bpy)3][CrO4]·7.5H2O (1) (bpy = 2,2′-bipyridine) was prepared in the crystalline form and characterized by X-ray diffraction and spectroscopic methods (EPR, FIR-IR, NIR–Vis–UV). Two non-equivalent [Cu(bpy)3]2+ groups in the form of tetragonally elongated octahedron are built into the hydrogen-bonded network. The tetragonality parameter T is 0.9830 and 0.9876 for Cu(1) and Cu(2) centers, respectively, points to the significant Jahn–Teller (JT) distortion in the tris-bipyridine copper(II) cations. The EPR parameters g1, g2 and g3 are equal to 2.168, 2.159 and 2.072, respectively, correspond to the Cu–N bond directions oscillating between long and short distances. The chromate moiety is a non-coordinated to the metal center and forms a very distorted tetrahedron with three bond lengths in the range 1.617(2)–1.629(2) Å. The O(3A) and O(3B) atoms execute reorientational motion between two equilibrium arrangements with equal probability. The related geometric distortion, Δr, is 0.097 Å. The Gaussian analysis of single crystal electronic spectra was based on the four d–d bands assigned for Cu(II) center to the 2A1g(dx2−y2) → 2A2g(dz2), 2B1g(dxy), 2B2g(dxz) and 2B3g(dyz) transitions in D2h symmetry. 相似文献
5.
James R. Beck Stephen A. Ackmann Michael A. Staszak Fred L. Wright 《Journal of heterocyclic chemistry》1988,25(3):955-958
A novel conversion of 5-amino-1-aryl-1H-pyrazole-4-carboxylic acid, ethyl esters to the corresponding 5-cyano esters is described. The process involves nonaqueous diazotization of the amine to form the methyl thioether, which is oxidized to the methyl sulfone, which, in turn, is displaced by cyanide ion. The cyano esters are precursors to chemical hybridizing agents in wheat and barley. 相似文献
6.
Marek Daszkiewicz Wiesawa Bronowska Adam Pietraszko Zbigniew Staszak Maria Cielak-Golonka 《Journal of Molecular Structure》2005,754(1-3):124-132
Nickel(II) chromate complex with imidazole (HIm) was isolated from the [Ni2+–HIm–CrO42−] system in various experimental conditions, i.e. reagent molar ratios and nickel(II) salts. The catena(μ-CrO4-O,O′)[Ni(HIm)3H2O] (1) crystallizes in monoclinic crystal system—space group P21/n with cell parameters: a=11.784(2), b=8.899(2), c=13.934(3) (Å), β=95.19(3) (°). The unit cell contains two independent helixes, left- and right-handed, stabilized by intrahelical and interhelical hydrogen bonds (HB) and π–π interactions. The cis coordination of the CrO42− anions and the HB systems appeared to be the main determinants of the helical architecture. To the best of our knowledge the cis-chromate coordination was observed for the first time. The cis coordination causes the distortion of the nickel octahedron, which was analysed by 4 K single crystal electronic spectra with D4h symmetry approximation (gaussian resolution and crystal field parameters). This symmetry was also confirmed with the polarised electronic spectra. The magnetic properties of the complex suggest the occurrence of weak intrachain antiferromagnetic interactions between the magnetic NiII center. The computational DFT studies of complex 1 assuming three possible isomers mer[(HIm)3]–cis[(CrO42−)2], mer–trans and fac–cis suggested that the main contribution to the stability of 1 might have interhelical and intrahelical hydrogen bonds. 相似文献
7.
The selective removal of Cu(II) in the presence of sodium dodecylobenzene sulfonate from acidic effluents was made using the adsorption and micellar-enhanced ultrafiltration methods. Lewatit MonoPlus TP220 showed the best adsorption behavior in the systems containing Cu(II) in the presence of ABSNa50 surfactant compared to the other adsorbents (removal efficiency ≈ 100%, sorption capacity ≈ 10 mg/g). The kinetics followed the pseudo-second order kinetic equation. The Langmuir adsorption capacities were 110 mg/g (the system with ABSNa50 above CMC) and 130.38 mg/g (the system with ABSNa50 below CMC). The working ion exchange capacities were Cw = 0.0216 g/mL and Cw = 0.0135 g/mL. The copper removal by the micellar-enhanced ultrafiltration method was 76.46% (0.1 mol/L HCl). 相似文献
8.
M. Staszak 《Theoretical and Computational Fluid Dynamics》2018,32(5):689-711
The work presents a new modeling technique designed for transporting selected property while simultaneously tracking particular value of certain field variable. The model addresses the problem of transportation of superficial properties according to fluid/fluid interface evolution. Such problem arises when some superficial variable needs to be attached to the evolving interface or front defined. Several multiphase models in CFD technique lack such ability. The model proposed is illustrated by the experimental two phase system of toluene/water with surfactant specie (sodium dodecylsulfate SDS). The selected superficial property that is important to be tracked according to interface evolution is Gibbs surface excess. The computation was performed using Ansys/Fluent software with proposed models created and attached using C programming language. 相似文献
9.
Equilibrium interfacial tension and surface excess isotherms for trioctylphosphine oxide (TOPO) were determined and interpreted. Despite its high hydrophobicity, TOPO adsorbs at the hydrocarbon/water interfaces and decreases effectively the interfacial tension. The interfacial activity of TOPO is affected by the type of organic diluent and the composition of the aqueous phase, i.e., the kind (HNO(3), KNO(3)) and the concentration of nonorganic electrolyte present in the system. Significant lowering of TOPO interfacial activity is observed with an increase of the aqueous phase acidity. The dynamic interfacial tension for TOPO was measured by using the drop volume technique. With the aid of the Ward and Tordai equation the values of the diffusion coefficients of TOPO were estimated. The values determined were in the right order of magnitude compared with the literature data. 相似文献
10.
Agnieszka Wojciechowska Marek Daszkiewicz Zbigniew Staszak Magdalena Boczar Julia Jezierska Maria Cieślak-Golonka 《Structural chemistry》2010,21(2):337-345
Novel copper(II) complex of the formula [Cu(phen)2OCrO3](phen)0.5
·4H2O (1) (phen = 1,10-phenantroline) was prepared in the crystalline form and characterized by X-ray diffraction and spectroscopic
methods (IR-FIR, NIR-Vis–UV, EPR). In the solid state, the CuN4O chromophore adopts a slightly distorted square-pyramidal geometry around the Cu2+ ion with a magnitude of a distortion parameter τ = 0.14. The chromate unit in (1) was found to be a monodentate. 相似文献