| 1. |
- Larsson, Anna-Carin, et al.
(author)
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Solid state 31P and 207Pb MAS NMR studies on polycrystalline O,O′-dialkyldithiophosphate lead(II) complexes
- 2005
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In: Journal of magnetic resonance. - : Elsevier BV. - 1090-7807 .- 1096-0856. ; 177:1, s. 56-66
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Journal article (peer-reviewed)abstract
- A number of lead(II) O,O′-dialkyldithiophosphate complexes were studied by 13C, 31P, and 207Pb MAS NMR. Simulations of 31P chemical shift anisotropy using spinning sideband analysis reveal a linear relationship between the SPS bond angle and the principal values δ22 and δ33 of the 31P chemical shift tensor. The 31P CSA data were used to assign ligands with different structural functions. In the cases of Adiethyldithiophosphate and di-iso-butyldithiophosphate lead(II) complexes, 2J (31P, 207Pb)-couplings were resolved and used to confirm the suggested assignment of the ligands. The SIMPSON computer program was used to calculate 31P and 207Pb spectral sideband patterns.
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| 2. |
- Rusanova, Daniela, et al.
(author)
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Formation of {Cu6[S2P(OC2H5)2]6} on Cu2S Surfaces from Aqueous Solutions of the KS2P(OC2H5)2 Collector: Scanning Electron Microscopy and Solid-State 31P Cross-Polarization/Magic Angle Spinning and Static 65Cu NMR Studies
- 2005
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In: Langmuir. - : American Chemical Society (ACS). - 0743-7463 .- 1520-5827. ; 21:10, s. 4420-4424
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Journal article (peer-reviewed)abstract
- The interactions of synthetic chalcocite surfaces with diethyldithiophosphate, potassium salt, K[S2P(OC2H5)2], were studied by means of 31P cross-polarization/magic angle spinning (CP/MAS) NMR spectroscopy and scanning electron microscopy (SEM). To identify the species formed on the Cu2S surfaces, a polycrystalline {CuI6[S2P(OC2H5)2]6} cluster was synthesized and analyzed by SEM, powder X-ray diffraction techniques and solid-state 31P CP/MAS NMR and static 65Cu NMR spectroscopy. 31P chemical shift anisotropy (CSA) parameters, CS and CS, were estimated and used for assigning the bridging type of diethyldithiophosphate ligands in the {CuI6[S2P(OC2H5)2]6} cluster. The latter data were compared to 31P CSA parameters estimated from the spinning sideband patterns in 31P NMR spectra of the collector-treated mineral surfaces: formation of polycrystalline {CuI6[S2P(OC2H5)2]6} on the Cu2S surfaces is suggested. The second-order quadrupolar line shape of 65Cu was simulated, and the NMR interaction parameters, CQ and Q, for the copper(I) diethyldithiophosphate cluster were obtained.
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| 3. |
- Rusanova, Daniela, et al.
(author)
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Formation of Ο,Ο’-di-alkyl-dithiophosphate copper (I) complexes on the surface of synthetic chalcocite : NMR and SEM studies
- 2005
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In: Centenary of Flotation Symposium Proceedings. - : The Australian Institute of Mining and Metallurgy. - 9781920806316 ; , s. 581-590
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Conference paper (peer-reviewed)abstract
- The adsorption mechanism of three different 0,0'-di-alkyl-dithiophosphate (dtp) collectors, K[S22P(OR)2] with R = Et, i-Bu and i'-Amyl, on the surface of synthetic chalcocite (Cu2S)Was studied by means of solid-state 31P CP/MAS NMR spectroscopy. The morphology changes on the conditioned (Cu2S) surfaces, in the collector concentration range 0.1 - 10 mM, were also monitored with scanning electron microscope (SEM). In order to assign Cu(I)-dtp species on the surface of CU 2S, the corresponding bulk Cu(I)-dtp compounds, which are clusters of the monovalent copper containing either Cu6(antiprismatic) or Cu8(cubic) cores, were synthesised, and characterised by means of solid-state 31P CP/MAS and static 65Cu NMR. Further investigations on the crystal habits of the bulk systems were carried out by powder x-ray diffraction and SEM. A comparative analysis of the 31P chemical shift and chemical shift anisotropy (CSA) data estimated from the experimental NMR spectra of the polycrystalline bulk Cu(l) dialkyldithiophosphate complexes was used for assigning the 31P resonance lines in the NMR spectra of the collector treated CU2S powder samples. The species formed on the synthetic Cu2S surfaces were assigned to polycrystalline phases of: Cu6L6 with L = Et2dtp̄μ, Cu6L6, and Cu 8L6(S) with L = i'-Bu2dtp̄, and 3. Cu 8L6S) with L = i-Amyl2dtp̄. A heterophase autocatalytic step process of both formation and growth of solid Cu xLy (L = R2dtp, x = 6 or 8 and y = 6) complexes on the collector treated CU2S surface is proposed. A possible role of the oxidised form of dithiophosphate collectors, bis[di-alkyl-thiophosphoryl] -disulfane (disulfide), is discussed in terms of a specific self-redox reaction. The second order quadrupolar lineshapes in 65Cu NMR spectra were simulated and the interaction parameters, CQ and nQ, for the bulk dialkyldithiophosphato-copper(I) complexes were obtained
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| 4. |
- Rusanova, Daniela, et al.
(author)
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Solid-state 31P CP/MAS and static 65Cu NMR characterization of polycrystalline copper(I) dialkyldithiophosphate clusters
- 2006
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In: Journal of magnetic resonance. - : Elsevier BV. - 1090-7807 .- 1096-0856. ; 179:1, s. 140-145
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Journal article (peer-reviewed)abstract
- Polycrystalline tetra-nuclear Cu4[S2P(O-i-C3H7)2]4, hexa-nuclear Cu6[S2P(OC2H5)2]6, and octa-nuclear Cu8[S2P(O-i-C4H9)2]6(S) complexes were synthesized and analyzed by means of solid-state 31P CP/MAS and 65Cu static NMR spectroscopy. The symmetries of the electronic environments around each P-site were estimated from the 31P chemical shift anisotropy (CSA) parameters, Δaniso and η. The 65Cu chemical shift and quadrupolar splitting parameters obtained from the experimental 65Cu NMR spectra of the polycrystalline CuI-complexes are presented. A solid-state NMR approach for the elucidation of the stereochemistry of poly-nuclear Cu(I) dithiophosphate complexes, when the structural analysis of the systems by single-crystal X-ray diffraction is not readily available, is proposed.
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| 5. |
- Rusanova, Daniela, et al.
(author)
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Solid-state NMR and EXAFS spectroscopic characterization of infoPolycrystalline copper(I) O,O prime -Dialkvldithiophosphate cluster compounds : Formation of copper(I) O,O prime -diisobutyklithiophosphate compounds on the surface of synthetic chalcocite
- 2006
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In: Chemistry - A European Journal. - : Wiley. - 0947-6539 .- 1521-3765. ; 12:20, s. 5282-5292
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Journal article (peer-reviewed)abstract
- A number of polycrystalline copper(I) O,O-dialkyldithiophosphate cluster compounds with Cu4, Cu6, and Cu8 cores were synthesized and characterized by using extended X-ray absorption fine-structure (EXAFS) spectroscopy. The structural relationship of these compounds is discussed. The polycrystalline copper(I) O,O-diisobutyldithiophosphate cluster compounds, [Cu8{S2P(OiBu)2}6(S)] and [Cu6{S2P(OiBu)2}6], were also characterized by using 31P CP/MAS NMR (CP = cross polarization, MAS = magic-angle spinning) and static 65Cu NMR spectroscopies (at different magnetic fields) and powder X-ray diffraction (XRD) analysis. Comparative analyses of the 31P chemical-shift tensor, and the 65Cu chemical shift and quadrupolar-splitting parameters, estimated from the experimental NMR spectra of the polycrystalline copper(I) cluster compounds, are presented. The adsorption mechanism of the potassium O,O-diisobutyldithiophosphate collector, K[S2P(OiBu)2], at the surface of synthetic chalcocite (Cu2S) was studied by means of solid-state 31P CP/MAS NMR spectroscopy and scanning electron microscopy (SEM). 31P NMR resonance lines from collector-treated chalcocite surfaces were assigned to a mixture of [Cu8{S2P(OiBu)2}6(S)] and [Cu6{S2P(OiBu)2}6] compounds.
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| 6. |
- Rusanova, Daniela, et al.
(author)
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Solid-state static 65Cu and 31P CP/MAS NMR, and liquid-state EXAFS studies on copper(I) O,O′-dialkyldithiophosphate cluster compounds : formation of the copper(I) O,O′-di-iso-amyldithiophosphate cluster compound on the surface of synthetic chalcocite
- 2006
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In: Polyhedron. - : Elsevier BV. - 0277-5387 .- 1873-3719. ; 25:18, s. 3569-3580
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Journal article (peer-reviewed)abstract
- Polycrystalline octa-nuclear copper(I) O,O′-di-i-propyl- and O,O′-di-i-amyldithiophosphate cluster compounds, {Cu8[S2P(OR)2]6(μ8-S)} where R = iPr and iAm, were synthesized and characterized by 31P CP/MAS NMR at 8.46 T and static 65Cu NMR at multiple magnetic field strengths (7.05, 9.4 and 14.1 T). The symmetries of the electronic environments around the P sites were estimated from the 31P chemical shift anisotropy (CSA) parameters, δaniso and η. Analyses of the 65Cu chemical shift and quadrupolar splitting parameters for these compounds are presented with the data being compared to those for the analogous octa-nuclear cluster compounds with R = nBu and iBu. The 65Cu transverse relaxation for the copper sites in {Cu8[S2P(OiPr)2]6(μ8-S)} and {Cu8[S2P(OiAm)2]6(μ8-S)} was found to be very different, with a relaxation time, T2, of 590 μs (Gaussian) and 90 μs (exponential), respectively. The structures of {Cu4[S2P(OiPr)2]4} and {Cu8[S2P(OiPr)2]6(μ8-S)} cluster compounds in the liquid- and the solid-state were studied by Cu K-edge EXAFS. The disulfide, [S2P(OiAm)2]2, was obtained and characterized by 31P{1H} NMR. The interactions of the disulfide and of the potassium O,O′-di-i-amyldithiophosphate salt with the surfaces of synthetic chalcocite (Cu2S) were probed using solid-state 31P NMR spectroscopy and only the presence of copper(I) dithiophosphate species with the {Cu8[S2P(OiAm)2]6(μ8-S)} structure was observed.
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| 7. |
- Rusanova, Daniela, et al.
(author)
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Spectroscopic characterization of the polycrystalline copper(I) di-n-butyldithiophosphate cluster - Cu8[S2P(O-n-Bu)2]6(μ8-S): Solid-state 31P CP/MAS and static 65Cu NMR studies
- 2006
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In: Inorganica Chimica Acta. - : Elsevier BV. - 0020-1693 .- 1873-3255. ; 259:12, s. 3903-3910
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Journal article (peer-reviewed)abstract
- A polycrystalline copper(I) O,O′-di-n-butyldithiophosphate cluster compound, Cu8[S2P(O-n-Bu)2]6(μ8-S), was synthesized and characterized by 31P CP/MAS NMR at 8.46 T and static 65Cu NMR at multiple magnetic field strengths (7.05, 9.4 and 14.1 T). The principal values of the 31P chemical shift tensor and the 65Cu chemical shift and quadrupolar splitting parameters are presented. The data are compared to those for the analogous octa-nuclear cluster compounds [Cu8(S2P(OEt)2)6(μ8-S)], [Cu8(S2P(O-n-Pr)2)6(μ8-S)] and [Cu8(S2P(O-i-Bu)2)6(μ8-S)]. The transverse relaxation time constant, T2, for the [Cu8(S2P(O-n-Bu)2)6(μ8-S)] cluster compound was found to be 160 ± 8 μs. Possible intra-molecular motions in the cluster structures in terms of size and branching of the hydrocarbon chains are discussed as reasons for the different 65Cu NMR responses of the systems.
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