Cation ordering in natural and synthetic (Cu(1-x)Zn(x))(2)CO(3)(OH)(2) and (Cu(1-x)Zn(x))(5)(CO(3))(2)(OH)(6)

In the present paper we report combined experimental and theoretical studies of the UV-vis-NIR spectra of the mineral compounds malachite, rosasite, and aurichalcite and of the precursor compounds for Cu/ZnO catalysts. For the copper species in the minerals the crystal field splitting and the vibronic coupling constants are estimated using the exchange charge model of the crystal field accounting for the exchange and covalence effects. On this basis the transitions responsible for the formation of the optical bands arising from the copper centers in minerals are determined and the profiles of the absorption bands corresponding to these centers are calculated. The profiles of the absorption bands calculated as a sum of bands of their respective Cu species are in quite good agreement with the experimental data. In agreement with crystal chemical considerations, the Zn ions were found to be preferentially located on the more regular, i.e., less distorted, octahedral sites in zincian malachite and rosasite, suggesting a high degree of metal ordering in these phases. This concept also applies for the mineral aurichalcite, but not for synthetic aurichalcite, which seems to exhibit a lower degree of metal ordering. The catalyst precursor was found to be a mixture of zincian malachite and a minor amount of aurichalcite. The best fit of the optical spectrum is obtained assuming a mixture of contributions from malachite (0% Zn) and rosasite (38% Zn of [Zn + Cu]), which is probably due to the intermediate Zn content of the precursor (30%).     

Alloyed (ZnS)(x)(Cu2SnS3)(1-x) and (CuInS2)(x)(Cu2SnS3)(1-x) nanocrystals with arbitrary composition and broad tunable band gaps

Cu(2)SnS(3) nanocrystals with metastable zincblende and wurtzite structures have been successfully synthesized for the first time. Alloyed (ZnS)(x)(Cu(2)SnS(3))(1-x) and (CuInS(2))(x)(Cu(2)SnS(3))(1-x) nanocrystals with arbitrary composition (0 ≤x≤ 1) and ultra-broad tunable band gaps (3.63 to 0.94 eV) were obtained.     

Copper and Bismuth Complexes Containing Dipyridyl gem-Diolato Ligands: Bi(III)(2)[(2-Py)(2)CO(OH)](2)(O(2)CCF(3))(4)(THF)(2), Cu(II)[(2-Py)(2)CO(OH)](2)(HO(2)CCH(3))(2), and Cu(II)(4)[(2-Py)(2)CO(OH)](2)(O(2)CCH(3))(6)(H(2)O)(2), a Ferromagnetically Coupled Tetranuclear Copper(II) Chain

The reactions of the singly deprotonated di-2-pyridylmethanediol ligand (dpmdH(-)) with copper(II) and bismuth(III) have been investigated. A new dinuclear bismuth(III) complex Bi(2)(dpmdH)(2)(O(2)CCF(3))(4)(THF)(2), 1, has been obtained by the reaction of BiPh(3) with di-2-pyridyl ketone in the presence of HO(2)CCF(3) in tetrahydrofuran (THF). The reaction of Cu(OCH(3))(2) with di-2-pyridyl ketone, H(2)O, and acetic acid in a 1:2:2:2 ratio yielded a mononuclear complex Cu[(2-Py)(2)CO(OH)](2)(HO(2)CCH(3))(2), 2, while the reaction of Cu(OAC)(2)(H(2)O) with di-2-pyridyl ketone and acetic acid in a 2:1:1 ratio yielded a tetranuclear complex Cu(4)[(2-Py)(2)CO(OH)](2)(O(2)CCH(3))(6)(H(2)O)(2), 3. The structures of these complexes were determined by single-crystal X-ray diffraction analyses. Three different bonding modes of the dpmdH(-) ligand were observed in compounds 1-3. In 2, the dpmdH(-) ligand functions as a tridentate chelate to the copper center and forms a hydrogen bond between the OH group and the noncoordinating HO(2)CCH(3) molecule. In 1 and 3, the dpmdH(-) ligand functions as a bridging ligand to two metal centers through the oxygen atom. The two pyridyl groups of the dpmdH(-) ligand are bound to one bismuth(III) center in 1, while in 3 they are bound two copper(II) centers, respectively. Compound 3 has an unusual one dimensional hydrogen bonded extended structure. The intramolecular magnetic interaction in 3 has been found to be dominated by ferromagnetism. Crystal data: 1, C(38)H(34)N(4)O(14)F(12)Bi(2), triclinic P&onemacr;, a = 11.764(3) ?, b = 11.949(3) ?, c = 9.737(1) ?, alpha =101.36(2) degrees, beta = 105.64(2) degrees, gamma = 63.79(2) degrees, Z = 1; 2, C(26)H(26)N(4)O(8)Cu/CH(2)Cl(2), monoclinic C2/c, a = 25.51(3) ?, b = 7.861(7) ?, c = 16.24(2) ?, beta = 113.08(9) degrees, Z = 4; 3, C(34)H(40)N(4)O(18)Cu(4)/CH(2)Cl(2), triclinic P&onemacr;, a = 10.494(2) ?, b = 13.885(2) ?, c = 7.900(4) ?, alpha =106.52(2) degrees, beta = 90.85(3) degrees, gamma = 94.12(1) degrees, Z = 1.     

Ba2(BO3)(1-x)(CO3)(x)Cl(1+x): a mixed borate and carbonate chloride crystallized from high-temperature solution

A mixed borate and carbonate chloride Ba(2)(BO(3))(1-x)(CO(3))(x)Cl(1+x) was obtained by spontaneous crystallization from a high-temperature melt in open air. It crystallizes in the trigonal crystal system with space group of P3m?1 and lattice constants of a = 5.4708(8) ? and c = 10.640(2) ?. The structure can be viewed as an intergrowth of trigonal Ba(2)Mg(BO(3))(2) (001) slab and (111) slab of the cubic fluorite BaCl(2). During Fourier analysis of the single-crystal X-ray diffraction data, additional electron density was found locating at 1b (0, 0, 1/2) site and attributed to chlorine surplus, which was confirmed by chemical titration. Charge balance of the compound was found, unexpectedly in an acidic borate containing high-temperature melt, by partial CO(3)(2-) group substituting the BO(3)(3-) group. The existence of CO(3)(2-) anion in the crystal was detected by thermogravimetry-mass spectrum analysis and Raman spectrum. The transmittance spectrum shows that the crystal is transparent from ultraviolet to infrared with short-wavelength absorption edge at about 220 nm.     

PbCu3(OH)(NO3)(SeO3)3·1/2H2O und Pb2Cu3O2(NO3)2(SeO3)2: Synthese und Kristallstrukturuntersuchung

Crystals of PbCu₃(OH)(NO₃)(SeO₃)₃·1/2H₂O [a=7.761(3)Å,b=9.478(4)Å,c=9.514(4)Å, =66.94(2)°, =69.83(2)°, =81.83(2)°, space group P ,Z=2] and Pb₂Cu₃O₂(NO₃)₂(SeO₃)₂ [a=5.884(2)Å,b=12.186(3)Å,c=19.371(4)Å, space group Cmc2₁,Z=4] were synthesized under hydrothermal conditions. Their crystal structures were refined with three-dimensional X-ray data toR _w=0.033 resp. 0.055. In PbCu₃(OH)(NO₃)(SeO₃)₃·1/2H₂O the Cu atoms are [4+1] and [4+2] coordinated and via SeO₃ groups a three-dimensional atomic arrangement is built up. In Pb₂Cu₃O₂(NO₃)₂(SeO₃)₂ there are sheets, which are connected only via Pb-O bonds ranging from 2.98 Å to 3.16 Å.

     

Synthesis,X-ray structure and properties of the trinuclear copper(I) complex [Cu3(dppm)3(NO3)(OH)](NO3)

The novel trinuclear Cu^I complex [Cu₃(dppm)₃(NO₃)(OH)](NO₃) obtained by reacting dppm with Cu(NO₃)₂ · 3H₂O in the presence of NaBPh₄ was characterized by a single-crystal X-ray analysis as well as by physico-chemical and spectroscopic methods. The [Cu₃(dppm)₃(NO₃)(OH)]⁺ cation consists of a triangular array of copper atoms, (with dppm ligands bridging each edge of the triangle), a triply bridging OH group and NO^– ₃ anion bound to two faces of the Cu₃ unit, respectively.     

Co(NH3)6]3[Cu4(OH)(CO3)8].2H2O--a new carbonato-copper(II) anion stabilized by extensive hydrogen bonding

Addition of Co(NH3)6(3+) to aqueous solutions of Cu(II) in excess carbonate promotes the assembly of a new highly charged carbonato-copper(II) anion, [Cu4(OH)(CO3)8](9-), which contains an unusual mu4 hydroxo-bridged square Cu4 arrangement, stabilised in the crystal by no less than forty hydrogen bonds (< 3 Angstrom) to hexammine cations.     

Synthesis and crystal structure of New Amminecopper(II) Nitrates: [Cu(NH3)2](NO3)2 and [Cu(NH3)](NO3)2

[Cu(NH₃)₂](NO₃)₂ ( I ) and [Cu(NH₃](NO₃)₂ ( II ) were synthesized by interaction of molten NH₄NO₃ with [Cu(NH₃)₄](NO₃)₂ and Cu(NO₃)₂ · 3 H₂O, respectively, at 180 to 195°C for 24 hr. According to X-Ray single crystal analysis, I is orthorhombic (sp. gr. Pbca) with a = 5.678(1), b = 9.765(2), c = 11.596(2) Å, Z = 4, R = 0.060; II is monoclinic (sp. gr. P2₁/c) with a = 6.670(1), b = 8.658(2), c = 9.661(2) Å, β = 101.78(2)°, Z = 4, R = 0.027. In both structures, the nearest coordination environment of Cu is a slightly distorted square formed by N (from NH₃) and O atoms (from NO₃ groups). The structure of I consists of centrosymmetrical [Cu(NH₃)₂](NO₃)₂ molecules linked by hydrogen bonds. The Cu? N and Cu? O distances are 1.98 and 2.01 Å, respectively. In II , the Cu? N distance is 1.95 Å, the Cu? O distances are 1.96, 2.02, and 2.03 Å. The [CuO₃NH₃] squares are connected by NO₃ bridges into zigzag chains, which are linked into layers by longer Cu? O interactions (2.31 Å). Obviously, the layers are additionally strengthened and held together by hydrogen bonds.     

The Monohydrate of Basic Mercuric Nitrate, [Hg(OH)](NO3)(H2O)

Colourless single crystals of [Hg(OH)](NO₃)(H₂O) were obtained by slow evaporation of an aqueous solution of Hg(NO₃)₂ and Bi(NO₃)₃. The crystal structure (orthorhombic, Pbca, Z = 8, a = 943.2(2), b = 697.6(1), c = 1349.0(2) pm, R₁(all) = 0.0780) contains [Hg(OH)] = …OH–Hg–OH–Hg… zig zag chains (O–Hg–O angle: 168°, Hg–O–Hg angle: 112°, Hg–OH distance: 212 pm) to which one water molecule is attached loosely. The [Hg(OH)](H₂O) chains are connected via bis‐monodentate‐bridging nitrate ions to corrugated layers that are stacked in the [001] direction. Hg²⁺ has an effective 2+2+2(+1) coordination.     

Phasenumwandlungen im system Cu x II Mn 1−x II Fe 2 III (OH)8

Zusammenfassung Die gemeinsam gefällten, ursprünglich amorphen Cu(II)Mn(II)Fe(III) Hydroxide gehen im Verlauf der Alterung durch Kochen in kristalline Phasen über, von denen wenigstens eine den Alterungsprodukten ferromagnetische Eigenschaften verleiht. Da es nicht möglich ist direkt zu entscheiden ob-Fe₂O₃ oder entsprechende Ferrite diese Eigenschaft hervorrufen, ist es notwendig, sich für die Identifizierung der Alterungsprodukte die thermische Instabilität von-Fe₂O₃ nutzbar zu machen. Die an Mn(II) sehr reichen Präparate zeigen einen Temperaturinvervall, in welchem sie überhaupt keine ferromagnetischen Eigenschaften aufweisen. Es ist dies ein Beweis dafür, daß der primär während des Kochens erworbene Ferromagnetismus ausschließlich von-Fe₂O₃ herrührt. Der bei hohen Temperaturen erneut auftretende Ferromagnetismus ist eine Eigenschaft der infolge thermischer Bearbeitung entstehenden Ferrite.

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After being boiled in water, the originally amorphous mixture of coprecipitated Cu(II), Mn(II) and Fe(III) hydroxides is transformed into crystalline phases, at least one of them being ferromagnetic. Since it can not be ascertained directly whether this property is due to the presence of-Fe₂O₃ or/and a corresponding ferrite, the identification must be based on the thermally metastable nature of-Fe₂O₃.The species with high Mn(II) contents exhibit temperature ranges in which the ferromagnetic properties disappear completely. This is the proof that the primarily acquired ferromagnetism stems exclusively from a ferromagnetic modification of iron oxide, namely-Fe₂O₃.As a result of thermal treatment at higher temperatures, the ferromagnetism reappears, this time due to the formation of ferrites.

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Résumé Les mélanges initialement amorphes des hydroxydes coprécipités de Cu(II), Mn(II) et Fe(III), se transforment, après chauffage dans de l'eau bouillante, en phase cristallines, dont l'une au moins est ferromagnétique. Comme il n'est pas possible de s'assurer directement que cette propriété est conditionnée par la présence de-Fe₂O₃ et/ou du ferrite respectif, l'identification doit reposer sur la nature thermiquement métastable de-Fe₂O₃.Dans le cas des préparations à teneur élevée en manganèse il existe un intervalle de températures où les propriétés ferromagnétiques disparaissent complêtement. C'est la preuve de ce que le ferromagnétisme acquis primitivement provient exclusivement d'une modification ferromagnétique ou d'un oxyde, notamment-Fe₂O₃.Le traitement thermique à des températures plus élevées a pour résultat la réapparition du ferromagnétisme, cette fois dû à la formation de ferrites.

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Cu(II), Mn(II) Fe(III) , , , . , —Fe₂O₃ , , —Fe₂O₃. Mn(II) , . , , —Fe₂O₃. , , .

     

Single crystal EPR of Cu(II) doped [Co(tbz)2(NO3)(H2O)]NO3: probe into copper-thiabendazole interaction

EPR of Cu(II) doped, low symmetry Co(II)-thiabendazole complex [Co(tbz)2(NO3)(H2O)](NO3) is investigated at 300 K. The spin Hamiltonian parameters are found to be orthorhombic with g33=2.305, g22=2.1351, g11=2.0626 and A33=147.0 x 10(-4), A22=33.5 x 10(-4) and A11=23.1 x 10(-4) cm(-1). Computer simulation of isofrequency plots reveal that the Cu(II) ions is substitutionally incorporated in the host lattice. Angular variation of the spectra shows the presence of two magnetic sites in the lattice. The low magnitude of A33 of the complex is rationalized in terms of admixture of d(x2-y2)/d(z2) ground state and delocalization of unpaired spin density onto the ligands.     

Tuning of spin density wave strengths in quasi-one-dimensional mixed-halogen-bridged nickel(III) complexes with strong electron correlation, [Ni(III)(chxn)(2)Cl(1-x)Br(x)](NO(3))(2)

This communication describes the syntheses of the quasi-one-dimensional mixed-halogen-bridged Ni(III) complexes with strong electron correlation [Ni(chxn)(2)Cl(1-x)Br(x)](NO(3))(2) and the tuning of the spin density wave strengths of these compounds. If the Cl 3p and Br 4p make one band in the compounds, we should observe a single peak in the electronic spectra. As a result, we should observe the single peak from 1.45 to 2.00 eV depending on the mixing ratios of Cl and Br ions. Therefore, the Cl 3p and Br 4p make one band. Then, we have succeeded in tuning the spin density wave strengths of the Ni(III) complexes with the strong electron correlation by mixing the bridging halogen ions successively.     

Corner sharing tetrahedral network in Co(3)(HAT)[N(CN)(2)](6)(OH(2))(2) (HAT = 1,4,5,8,9,12-hexaazatriphenylene)

We report a trinuclear Co(II) complex containing bridging dicyanamides and a tris-chelated HAT, which possesses approximately 37% void space. The magnetic exchange pathways appear in the structure as a corner sharing tetrahedral network. The compound crystallizes in the monoclinic space group P2(1)/c [a = 13.655(3) A, b = 15.189(3) A, c = 22.367(4) A, beta = 114.100(2) degrees, V = 4234.5(14) A(3), Z = 4, R(F(o)) = 0.0823]. The magnetic data were fit to an S = 3/2 model for systems dominated by zero-field splitting effects with g = 2.01 and D = 38.9 cm(-1).     

双核配合物[Cu2(L-Asp)(phen)3(NO3)](NO3)·4H2O的合成及晶体结构

The new complex [Cu₂(L-Asp)(phen)₃(NO₃)](NO₃)·4H₂O (L-Asp=L-aspartic acid and phen=1,10-phenanthroline) has been synthesized and its crystal structure has been determined. The complex crystallizes in the monoclinic with space group P2₁/c, The cell parameters are: a=1.261 3(2) nm, b=1.500 8(4) nm, c=2.230 7(4) nm, β=99.55(1)°, and V=4.164 1(16) nm³，D_c=1.587 g·cm^-3. The complex contains two six-coordinated copper ions, and these two copper ions are connected together by L-aspartate to give rise to a binuclear structure. Hydrogen bonds and π-π stacking interactions are observed in the complex. CCDC: 249250.     

Ultrafast nonadiabatic dynamics of [Fe(II)(bpy)(3)](2+) in solution

The ultrafast relaxation of aqueous iron(II)-tris(bipyridine) upon excitation into the singlet metal-to-ligand charge-transfer band (1MLCT) has been characterized by femtosecond fluorescence up-conversion and transient absorption (TA) studies. The fluorescence experiment shows a very short-lived broad 1MLCT emission band at approximately 600 nm, which decays in < or =20 fs, and a weak emission at approximately 660 nm, which we attribute to the 3MLCT, populated by intersystem crossing (ISC) from the 1MLCT state. The TA studies show a short-lived (<150 fs) excited-state absorption (ESA) below 400 nm, and a longer-lived one above 550 nm, along with the ground-state bleach (GSB). We identify the short-lived ESA as being due to the 3MLCT state. The long-lived ESA decay and the GSB recovery occur on the time scale of the lowest excited high-spin quintet state 5T2 lifetime. A singular value decomposition and a global analysis of the TA data, based on a sequential relaxation model, reveal three characteristic time scales: 120 fs, 960 fs, and 665 ps. The first is the decay of the 3MLCT, the second is identified as the population time of the 5T2 state, while the third is its decay time to the ground state. The anomalously high ISC rate is identical in [RuII(bpy)3]2+ and is therefore independent of the spin-orbit constant of the metal atom. To reconcile these rates with the regular quasi-harmonic vibrational progression of the 1MLCT absorption, we propose a simple model of avoided crossings between singlet and triplet potential curves, induced by the strong spin-orbit interaction. The subsequent relaxation steps down to the 5T2 state dissipate approximately 2000 cm-1/100 fs. This rate is discussed, and we conclude that it nevertheless can be described by the Fermi golden rule, despite its high value.     

Structural and thermochemical chemisorption of CO2 on Li(4+x)(Si(1-x)Al(x))O4 and Li(4-x)(Si(1-x)V(x))O4 solid solutions

Different Li(4)SiO(4) solid solutions containing aluminum (Li(4+x)(Si(1-x)Al(x))O(4)) or vanadium (Li(4-x)(Si(1-x)V(x))O(4)) were prepared by solid state reactions. Samples were characterized by X-ray diffraction and solid state nuclear magnetic resonance. Then, samples were tested as CO(2) captors. Characterization results show that both, aluminum and vanadium ions, occupy silicon sites into the Li(4)SiO(4) lattice. Thus, the dissolution of aluminum is compensated by Li(1+) interstitials, while the dissolution of vanadium leads to lithium vacancies formation. Finally, the CO(2) capture evaluation shows that the aluminum presence into the Li(4)SiO(4) structure highly improves the CO(2) chemisorption, and on the contrary, vanadium addition inhibits it. The differences observed between the CO(2) chemisorption processes are mainly correlated to the different lithium secondary phases produced in each case and their corresponding diffusion properties.     

Zwei neue basische Yttrium-Nitrate: Y(OH) x (NO3)3−x ·H2O und YO x/2(NO3)3−x (x=1.5)

Summary The intermediate precipitate, resulting by thermal decomposition and stepwise hydrolysis of yttrium-nitrate, was investigated by chemical analysis, TG, IR, and X-ray powderdiagrams and was found to be a definite hydroxynitrate Y(OH)_1.5(NO₃)_1.5·H₂O. Thermal decomposition resulted in the oxynitrate YO_0.75(NO₃)_1.5, stable from 140–280°C, which was characterized in an analogous manner.

     

Ge(7)O(13)(OH)(2)F(3)](3)(-).Cl(-).2[Ni(dien)(2)](2+): the first chainlike germanate templated by a transition metal complex

The first chainlike germanate, [Ge(7)O(13)(OH)(2)F(3)](3)(-).Cl(-).2[Ni(dien)(2)](2+), has been solvothermally synthesized by using Ni(dien)(2)(2+) cations as the template and characterized by IR, SEM, TGA, powder X-ray diffraction (PXRD), energy-dispersive X-ray analysis (EDXA), elemental analysis, and single-crystal X-ray diffraction, respectively. This compound crystallized in the monoclinic space group P2/nwith a = 8.8904(2) A, b = 17.4374(3) A, c = 13.2110(3) A, beta = 101.352(1) degrees, V = 2007.97(7) A(3), and Z = 2. Interestingly, the structure contains two types of chiral mer-[Ni(dien)(2)](2+) cations and two types of chiral chains, one left-handed and the other right-handed, which lead to a racemic compound. The orderly separation of achiral s-fac-[Ni(dien)(2)](2+) and chiral mer-[Ni(dien)(2)](2+) isomers was found in the structure. The structure is stabilized by N-H.O(F, Cl) hydrogen bonds.     

Nanoporous Pt@Au(x)Cu(100-x) by hydrogen evolution assisted electrodeposition of Au(x)Cu(100-x) and galvanic replacement of Cu with Pt: electrocatalytic properties

Electrodeposition of high-surface-area nanoporous Au-Cu foams under conditions of hydrogen codeposition is studied. The honeycomb-like Au(x)Cu(100-x) foams with 0 ≤ x ≤ 100 are electrodeposited by controlling the amount of corresponding ions in the solution. The amount of metal ions in deposited films follows that in used electrolytes. Compared to monometallic foams, the Au(x)Cu(100-x) structures are characterized by smaller ligament or particle sizes (less than 10 nm) and improved stability. The addition of even a small amount of Cu to the Au matrix is found to dramatically improve the stability of the structure in air environment or an acidic medium. Pt@Au(x)Cu(100-x) structures are formed by the galvanic displacement of Cu from Au(x)Cu(100-x) templates. During the displacement of Cu by Pt, Au serves as a buffer, decreasing mechanical stresses and preventing the detachment of the foam from the substrate. The surface ratio of Pt to Au atoms is controlled by adjusting the amount of Cu in the template. Pt@Au(x)Cu(100-x) electrodes are investigated as novel electrocatalysts for methanol oxidation in alkaline media. The Au-enriched surfaces show higher catalytic activity toward methanol oxidation, while the electrodes with a higher amount of Pt are more stable.     

Photomagnetic studies on spin-crossover solid solutions containing two different metal complexes, [Fe(1-bpp)(2)](x)[M(terpy)2](1-x)[BF4]2 (M = Ru or Co)

The photomagnetic properties of two series of spin-crossover solid solutions, [Fe(1-bpp)(2)](x)[Ru(terpy)(2)](1-x)(BF(4))(2) and [Fe(1-bpp)(2)](x)[Co(terpy)(2)](1-x)(BF(4))(2) (1-bpp = 2,6-bis[pyrazol-1-yl]pyridine), have been investigated. For all the materials, the evolution of the T(LIESST) value, the high-spin → low-spin relaxation parameters and the LITH loops were thoroughly studied. Interestingly in the Fe:Co series, along the photo-excitation, cobalt ions are concomitantly converted from low-spin to high-spin states with the iron centres, and also fully relax after light excitation.