Homochiral porous lanthanide phosphonates with 1D triple-strand helical chains: synthesis, photoluminescence, and adsorption properties

Four homochiral porous lanthanide phosphonates, [Ln(H2L)3].2H2O, (H3L = (S)-HO3PCH2-NHC4H7-CO2H, Ln = Tb (1), Dy (2), Eu (3), Gd (4)), have been synthesized under hydrothermal conditions. These compounds are isostructural, and they possess a 3D supramolecular framework built up from 1D triple-strand helical chains. Each of the helical chain consists of phosphonate groups bridging adjacent Ln(III) ions. The helical chains are stacked through hydrogen bonds to form 1D tubular channels along the c axis. Moreover, helical water chains are located in the 1D channels, and after removal of these water chains, the compounds exhibit selective adsorption capacities for N2, H2O, and CH3OH molecules. Compounds 1 and 3 show strong green and red fluorescent emissions, respectively, in the solid state at room temperature. Crystal data for 1: TbP3O17N3C18H37, tetragonal (No.76), space group P4(1), a = 12.4643(3) Angstrom, b = 12.4643(3) Angstrom, c = 18.7577(5) Angstrom, V = 2914.17(13) Angstrom(3), and Z = 4. For 2: DyP3O17N3C18H37, a = 12.4486(3) Angstrom, b = 12.4486(3) Angstrom, c = 18.7626(5) Angstrom, V = 2907.60(13) Angstrom(3), and Z = 4. For 3, EuP3O17N3C18H37, a = 12.4799(3) Angstrom, b = 12.4799(3) Angstrom, c = 18.8239(5) Angstrom, V = 2931.78(13) Angstrom(3), and Z = 4. For 4: GdP3O17N3C18H37, a = 12.4877(18) Angstrom, b = 12.4877(18) Angstrom, c = 18.824(4) Angstrom, V = 2935.5(8) Angstrom(3), and Z = 4.     

Synthesis and characterization of four metal-organophosphonates with one-, two-, and three-dimensional structures

A series of metal-organic hybrid compounds were synthesized using two new phosphonic acids, pyridyl-4-phosphonic acid and p-xylylenediphosphonic acid (H(2)O(3)PCH(2)C(6)H(4)CH(2)PO(3)H(2)). The phosphonic acid ligands have been synthesized from their corresponding bromides following two different types of reactions. The reaction of pyridyl-4-phosphonic acid with three different divalent metal salts results in the formation of molecular structures of different dimensionality. The reaction of Cu(II) with the phosphonic acid under hydrothermal conditions yields a three-dimensional (3D) open framework structure having the molecular formula [Cu(4)(NC(5)H(4)-PO(3))(4)(H(2)O)(10)] (1). The reactions with Mn(II) and Zn(II) salts with the same phosphonic acid resulted in a two-dimensional layered and a dinuclear compound with molecular formulas [Mn(3)(NC(5)H(4)-PO(3))(4)(H(2)O)(6)(ClO(4))(2)] (2) and [Zn(2)(NHC(5)H(4)-PO(3)H)(2)Cl(4)] (3), respectively. Compound 1 crystallizes in the triclinic crystal system having space group P with structural parameters a = 7.4564(15) Angstrom, b = 9.1845(19) Angstrom, c = 11.582(2) Angstrom, alpha = 100.842(3) degrees, beta = 104.303(3) degrees, gamma = 94.774(3) degrees, and Z = 1. Compound 2 crystallizes in the triclinic crystal system, space group P, with structural parameters a = 7.6871(14) Angstrom, b = 10.576(2) Angstrom, c = 14.470(3)Angstrom, alpha = 81.340(3) degrees, beta = 81.561(3) degrees, gamma = 68.757(3) degrees, and Z = 2, whereas compound 3 crystallizes in a monoclinic crystal system with space group P2(1)/n. The structural parameters are as follows: a = 8.4969 (5) Angstrom, b = 9.3911 (5) Angstrom, c = 12.3779 (6) Angstrom, beta = 90.860(17) degrees, and Z = 4. The pyridylphosphonate ligand shows different ligation behavior toward the three divalent metal ions. On the other hand, p-xylylenediphosphonic acid on reaction with Co(II) formed a 3D compound [Co(2)(O(3)PCH(2)C(6)H(4)CH(2)PO(3))(2)(H(2)O)(2)] (4) with a layered and pillared structure. Compound 4 crystallizes in an orthorhombic crystal system with space group Pnma. The structural parameters are a = 21.744(4) Angstrom, b = 5.6744(10) Angstrom, c = 4.7927(9) Angstrom, and Z = 4.     

Binuclear palladium(I) and palladium(II) complexes of ortho-functionalized 1,3-bis(aryl)triazenido ligands

Three new bis(aryl)triazene ligands, Ar-NNNH-Ar' [Ar = o-C(6)H(4)-CO(2)Me, Ar' = p-C(6)H(4)-CH(3) (2); Ar = Ar' = o-C(6)H(4)-CO(2)Me (3); Ar = o-C(6)H(4)-SMe, Ar' = p-C(6)H(4)-CH(3)) (4)], have been synthesized. The reaction of 1-4 with PdCl(2)(NCCH(3))(2) in the presence of a base afforded a series of binuclear diamagnetic palladium complexes. In these reactions, ligands 1-3 afforded the palladium(I) complexes [Pd(I)(o-MeO(2)C-C(6)H(4)-NNN-o-C(6)H(4)-CO(2)Me)](2) (5, monoclinic, space group P21/c, a = 8.6070(10) Angstrom, b = 14.3220(10) Angstrom, c = 12.7310(10) Angstrom, beta = 100.2950(10) degrees, Z = 2), [Pd(I)(o-MeO-C(6)H(4)-NNN-o-C(6)H(4)-OMe)](2) (6, triclinic, space group P, a = 6.6288(5) Angstrom, b = 10.2631(10) Angstrom, c = 11.0246(11) Angstrom, alpha = 85.579(6) degrees, beta = 80.885(6) degrees, gamma = 74.607(6) degrees, Z = 1), and [Pd(I)(o-MeO(2)C-C(6)H(4)-NNN-p-C(6)H(4)-CH(3))](2) (7, tetragonal, space group I41/a, a = 20.866(3) Angstrom, b = 20.866(3) Angstrom, c = 13.156(2) Angstrom, Z = 8). In contrast, the reaction of ligand 4 with PdCl(2)(NCCH(3))(2) resulted in the formation of a palladium(II) dimer, [Pd(II)(o-MeS-C(6)H(4)-NNN-p-C(6)H(4)-CH(3))Cl](2) (8, orthorhombic, space group P2(1)2(1)2, a = 10.4058(5) Angstrom, b = 16.2488(8) Angstrom, c = 9.9500(5) Angstrom, Z = 2).     

Rare-earth metal-rich antimonides: syntheses, structures, and properties of Tm(3)Sb and Lu(7)Sb(3)

The two most metal-rich lanthanide antimony phases known were obtained from high-temperature solid state syntheses, that for Tm3Sb being of greater difficulty because of its apparent incongruent melting. The Tm3Sb phase crystallizes in the tetragonal space group P42/n (No. 86) with a Ti3P-type (Pearson: tP32) structure, a = 12.2294(5) Angstrom, c = 5.9852(5) Angstrom, and Z = 8. The phase Lu7Sb3 exhibits a Sc7As3-type tetragonal structure, I4/mcm (No. 140) (tI56), with a = 15.5974(7) Angstrom, c = 8.8130(7) Angstrom, and Z = 8. Both structures are described in terms of compact arrays of condensed chains of metal polyhedra (tetrahedral, tetrahedral star, trigonal prismatic, cubic) together with six- to nine-coordinate Sb in metal polyhedra. Magnetic susceptibility data on the paramagnetic Tm3Sb are also reported.     

Reversible bromide-chloride exchange in zirconium cluster compounds: synthesis by means of ionic liquids, structures, and some spectral data of (EMIm)(4)[(Zr(6)Z)Br(18)] cluster phases (Z = Be, Fe)

The solid-state precursor cluster chlorides Na(4)[(Zr(6)Be)Cl(16)] and K[(Zr(6)Fe)Cl(15)] readily dissolve in Lewis-basic ionic liquids consisting of mixtures of EMIm-Br and AlBr(3) (EMIm: 1-ethyl-3-methyl-imidazolium) to give dark colored solutions. From these solutions, the cluster phases (EMIm)(4)[(Zr(6)Fe)Br(18)] (1) and (EMIm)(4)[(Zr(6)Be)Br(18)] (2) were obtained in acceptable yields. Crystallographic data of the isostructural phases are the following: monoclinic, P2(1)/c, Z = 2. The data for 1 follow: a = 10.5746(4) Angstrom, b = 22.6567(9) Angstrom, and c = 13.0260(5) Angstrom, beta = 111.279(2) degrees. The data for 2 follow: a = 10.574(2) Angstrom, b = 22.681(4) Angstrom, and c = 13.041(2) Angstrom, beta = 111.31(2) degrees. Compound 1 is the first detailed structurally characterized molecular Fe-centered zirconium bromide cluster phase. In the bromide based ionic liquid, a complete exchange of all the outer and inner chlorides by bromide takes place. Since the inverse reaction, the exchange of all bromides by chlorides, was reported before, this complete ligand exchange can be considered as reversible, with the equilibrium being largely determined by the free ligand concentration. The electronic spectra of a chloride supported cluster precursor in different ionic liquids were measured and analyzed.     

Double-icosahedral Li clusters in a new binary compound Ba(19)Li(44): a reinvestigation of the Ba-Li phase diagram

The binary Ba-Li system was reinvestigated for compositions with less than 80 at. % Li. A new compound, Ba(19)Li(44), stable up to 126 degrees C, was found and structurally characterized. According to single-crystal X-ray diffraction data, the compound crystallizes in a new structure type with a tetragonal unit cell, space group I42d, a = 16.3911(5) Angstrom, c = 32.712(1) Angstrom, Z = 4, and V = 8788.7(5) Angstrom(3). It can be described as a complicated variant of the chalcopyrite structure. Typical for Li-rich phases, Ba(19)Li(44) contains icosahedron-based polytetrahedral clusters.     

X-ray crystal structure of phenylglycine hydrazide: synthesis and spectroscopic studies of its transition metal complexes

Phenylglycine hydrazide was synthesized and investigated by X-ray crystallography. It crystallizes in the monoclinic space group P121/c with cell parameters a=5.9459 (18) Angstrom, b=5.1940 (16) Angstrom, c=26.7793 (83) Angstrom and Z=2. Its conformational changes, on complexation with transition metal ions Cu(II), Co(II), Ni(II), Mn(II) and Zn(II) has been studied on the basis of elemental analysis, magnetic moment and spectral (IR, (1)H NMR, UV-vis) studies. The bidentate nature of the ligand was confirmed on the basis of a comparative IR and NMR spectral studies. The trigonal bipyramidal geometries were observed for Cu(II), Ni(II) and Co(II) complexes, while it is octahedral for the remaining complexes. The conductivity data suggest them to be non-electrolytes.     

Structural studies of the phase, aggregation and surface behaviour of 1-alkyl-3-methylimidazolium halide + water mixtures

The surface, phase and aggregation behaviour of mixtures of 1-alkyl-3-methylimidazolium halide, [C(n)mim]X, where n is the alkyl chain length, with water has been explored using a variety of methods. Critical micelle concentrations (cmc) and micelle structures have been determined for aqueous [C(n)mim]Br solutions for n=2, 4, 6, 8, and 10. Small-angle neutron scattering (SANS) measurements reveal that for the n=8 and 10 systems, at concentrations just above the cmc, small near-spherical aggregates exist, which, after initial growth, possess core radii (aggregation numbers) at intermediate concentrations of 10.5+/-0.5 Angstrom (22+/-2) and 13.2+/-0.5 Angstrom (40+/-3), respectively, for n=8 and n=10. Towards higher concentrations, the aggregates appear to grow, with the aggregates in the [C(10)mim]Br system becoming increasingly elongated (prolate) with increasing concentration. No evident aggregates are formed in the systems with n=2 and 4. In the n=6 system, it appears that oblate aggregates with radius approximately 9 Angstrom form at the cmc and that the radius increases with increasing concentration. For longer alkyl chain lengths, at high concentrations lyotropic mesophases form in some systems. The mesophase region for the [C(8)mim]Cl system has been explored across the composition range using X-ray diffraction and (2)H NMR spectroscopy. Both techniques suggest that a major hexagonal phase with lattice parameter of 29.5+/-0.5 Angstrom coexists with a minor lamellar phase (23.5+/-0.3 Angstrom) or possibly a second hexagonal phase (27.1+/-0.4 Angstrom). The area per adsorbed molecule at the surface of [C(8)mim]Br solutions has been measured as a function of concentration using neutron reflectometry. A minimum in the area per molecule behaviour is coincident with a minimum identified in the surface tension isotherm occurring close to the cmc. The data suggest depletion of [C(8)mim]Br from the surface region occurs at concentrations immediately above the cmc.     

Metal(II) hexafluorophosphates(V) (M = Sr, Pb) containing XeF(2)-coordinated metal ions [M(XeF(2))(3)](PF(6))(2), [Pb(3)(XeF(2))(11)](PF(6))(6), and [Sr(3)(XeF(2))(10)](PF(6))(6)

From the system MF(2)/PF(5)/XeF(2)/anhydrous hydrogen fluoride (aHF), four compounds [Sr(XeF(2))(3)](PF(6))(2), [Pb(XeF(2))(3)](PF(6))(2), [Sr(3)(XeF(2))(10)](PF(6))(6), and [Pb(3)(XeF(2))(11)](PF(6))(6) were isolated and characterized by Raman spectroscopy and X-ray single-crystal diffraction. The [M(XeF(2))(3)](PF(6))(2) (M = Sr, Pb) compounds are isostructural with the previously reported [Sr(XeF(2))(3)](AsF(6))(2). The structure of [Sr(3)(XeF(2))(10)](PF(6))(6) (space group C2/c; a = 11.778(6) Angstrom, b = 12.497(6) Angstrom, c = 34.60(2) Angstrom, beta = 95.574(4) degrees, V = 5069(4) Angstrom(3), Z = 4) contains two crystallographically independent metal centers with a coordination number of 10 and rather unusual coordination spheres in the shape of tetracapped trigonal prisms. The bridging XeF(2) molecules and one bridging PF(6)- anion, which connect the metal centers, form complicated 3D structures. The structure of [Pb(3)(XeF(2))(11)](PF(6))(6) (space group C2/m; a = 13.01(3) Angstrom, b = 11.437(4) Angstrom, c = 18.487(7) Angstrom, beta = 104.374(9) degrees, V = 2665(6) Angstrom(3), Z = 2) consists of a 3D network of the general formula {[Pb(3)(XeF(2))(10)](PF(6))(6)}n and a noncoordinated XeF(2) molecule fixed in the crystal structure only by weak electrostatic interactions. This structure also contains two crystallographically independent Pb atoms. One of them possesses a unique homoleptic environment built up by eight F atoms from eight XeF(2) molecules in the shape of a cube, whereas the second Pb atom with a coordination number of 9 adopts the shape of a tricapped trigonal prism common for lead compounds. [Pb(3)(XeF(2))(11)](PF(6))(6) and [Sr(3)(XeF(2))(10)](PF(6))(6) are formed when an excess of XeF(2) is used during the process of the crystallization of [M(XeF(2))(3)](PF(6))(2) from their aHF solutions.     

The hydration of the scandium(III) ion in aqueous solution and crystalline hydrates studied by XAFS spectroscopy, large-angle X-ray scattering and crystallography

The structures of the hydrated scandium(III) ion and of the hydrated dimeric hydrolysis complex, [Sc2(mu-OH)2]4+, in acidic aqueous solutions have been characterized by X-ray absorption fine structure (XAFS) and large-angle X-ray scattering (LAXS) methods. Comparisons with crystalline reference compounds containing hydrated scandium(III) ions in well characterized six-, seven- and eight-coordinated polyhedra have been used to evaluate the coordination numbers and configurations in aqueous solution. In strongly acidic aqueous solution the structure of the hydrated scandium(III) ion is found to be similar to that of the eight-coordinated scandium(III) ion with distorted bicapped trigonal prismatic coordinating geometry in the crystalline [Sc(H2O)(8.0)](CF3SO3)3 compound. The EXAFS data reveal for the solution, as for the solid, a mean Sc-O bond distance of 2.17(1) Angstrom to six strongly bound prism water molecules, 2.32(4) Angstrom to one capping position, with possibly another capping position at about 2.5 Angstrom. The LAXS study supports this structural model and shows furthermore a second hydration sphere with approximately 12 water molecules at a mean Sc...O(II) distance of 4.27(3) Angstrom. In less acidic concentrated scandium(III) aqueous solutions, the dimeric hydrolysis product, [Sc2(mu-OH)2(H2O)10]4+, is the predominating species with seven-coordinated scandium(III) ions in a double hydroxo bridge and five terminal water molecules at a mean Sc-O bond distance of 2.145 Angstrom. Hexahydrated scandium(III) ions are found in the crystal structure of the double salt [Sc(H2O)6][Sc(CH3SO3)6], which crystallizes in the trigonal space group R3[combining macron] with Z = 6 and the unit cell dimensions a = 14.019(2) and c = 25.3805(5) Angstrom. The Sc-O distances in the two crystallographically unique, but nearly identical, [Sc(H2O)6]3+ entities (both with 3[combining macron] imposed crystallographic symmetry) are 2.085(6) and 2.086(5) Angstrom, while the mean Sc-O distance in the near octahedral [Sc(OSO2CH3)6]3- entities (with three-fold symmetry) is 2.078 Angstrom.     

Rb(3)Ti(3)(P(4)S(13))(PS(4))(3) and Cs(2)Ti(2)(P(2)S(8))(PS(4))(2): two polar titanium thiophosphates with complex one-dimensional tunnels

The reactions of Ti with in situ formed polythiophosphate fluxes of A(2)S(3) (A = Rb, Cs), P(2)S(5), and S at 500 degrees C result in the formation of two new quaternary titanium thiophosphates with compositions Rb(3)Ti(3)(P(4)S(13))(PS(4))(3) (1) and Cs(2)Ti(2)(P(2)S(8))(PS(4))(2) (2). Rb(3)Ti(3)(P(4)S(13))(PS(4))(3) (1) crystallizes in the chiral hexagonal space group P6(3) (No. 173) with lattice parameters a = 18.2475(9) Angstrom, c = 6.8687(3) Angstrom, V = 1980.7(2) Angstrom(3), Z = 2. Cs(2)Ti(2)(P(2)S(8))(PS(4))(2) (2) crystallizes in the noncentrosymmetric monoclinic space group Cc (No. 9) with a = 21.9709(14) Angstrom, b = 6.9093(3) Angstrom, c = 17.1489(10) Angstrom, beta = 98.79(1) degrees, V = 2572.7(2) Angstrom(3), Z = 4. In the structure of 1 TiS(6) octahedra, three [PS(4)] tetrahedra, and the hitherto unknown [P(4)S(13)](6-) anion are joined to form two different types of helical chains. These chains are connected yielding two different helical tunnels being directed along [001]. The tunnels are occupied by the Rb+ ions. The [P(4)S(13)](6-) anion is generated by three [PS(4)] tetrahedra sharing corners with one [PS(4)] group in the center of the starlike anion. The P atoms of the three [PS(4)] tetrahedra attached to the central [PS(4)] group define an equilateral triangle. The [P(4)S(13)](6-) anion may be regarded as a new member of the [P(n)S(3n+1)]((n+2)-) series. The structure of Cs(2)Ti(2)(P(2)S(8))(PS(4))(2) (2) consists of the one-dimensional polar tunnels containing the Cs(+) cations. The rare [P(2)S(8)](4-) anion which is composed of two [PS(4)] tetrahedra joined by a S(2)(2-) anion is a fundamental building unit in the structure of 2. One-dimensional undulated chains being directed along [100] are joined by [PS(4)] tetrahedra to form the three-dimensional network with polar tunnels running along [010]. The compounds are characterized with IR, Raman spectroscopy, and UV/vis diffuse reflectance spectroscopy.     

Molecular structure of tris(dipivaloylmethanato)lutetium(iii) studied by gas electron diffraction and ab initio and DFT calculations

Combined gas electron diffraction/mass spectrometry (GED/MS) was used to determine the molecular structure of tris(dipivaloylmethanato)lutetium(III), Lu(dpm)(3)(dpm = 2,2,6,6-tetramethyl-heptane-3,5-dionato). Up to about 520-570 K the vapour consisted only of molecules Lu(dpm)(3). The experimental data recorded at 408(5) K indicate that the molecules have D(3) symmetry. The bond distances (r(h1)) in the chelate ring are Lu-O 2.197(6) Angstrom, C-O 1.270(4) Angstrom and C-C 1.390(6) Angstrom . Theoretical computations at the HF and DFT levels with basis sets up to 6-311G* afford structures similar to those found experimentally, with a distorted LuO(6) antiprism.     

Design and structure analysis of artificial metalloproteins: selective coordination of His64 to copper complexes with square-planar structure in the apo-myoglobin scaffold

apo-Myoglobin (apo-Mb) was reconstituted with three copper complexes: CuII(Sal-Phe) (1; Sal-Phe = N-salicylidene-L-phenylalanato), CuII(Sal-Leu) (2; Sal-Leu = N-salicylidene-L-leucinato), and CuII(Sal-Ala) (3; Sal-Ala = N-salicylidene-L-alanato). The crystal structures of 1.apo-Mb (1.65 Angstrom resolution) and 2.apo-Mb (1.8 Angstrom resolution) show that the coordination geometry around the CuII atom in apo-Mb is distorted square-planar with tridentate Sal-X and a Nepsilon atom of His64 in the apo-Mb cavity and the plane of these copper complexes is perpendicular to that of heme. These results suggest that the apo-Mb cavity can hold metal complexes with various coordination geometries.     

EXAFS investigation of U(VI), U(IV), and Th(IV) sulfato complexes in aqueous solution

The local structure of U(VI), U(IV), and Th(IV) sulfato complexes in aqueous solution was investigated by U-L(3) and Th-L(3) EXAFS spectroscopy for total sulfate concentrations 0.05 < or = [SO(4)(2-)] < or = 3 M and 1.0 < or = pH < or = 2.6. The sulfate coordination was derived from U-S and Th-S distances and coordination numbers. The spectroscopic results were combined with thermodynamic speciation and density functional theory (DFT) calculations. In equimolar [SO(4)(2-)]/[UO(2)(2+)] solution, a U-S distance of 3.57 +/- 0.02 Angstrom suggests monodentate coordination, in line with UO(2)SO(4)(aq) as the dominant species. With increasing [SO(4)(2-)]/[UO(2)(2+)] ratio, an additional U-S distance of 3.11 +/- 0.02 Angstrom appears, suggesting bidentate coordination in line with the predominance of the UO(2)(SO(4))(2)(2-) species. The sulfate coordination of Th(IV) and U(IV) was investigated at [SO(4)(2-)]/[M(IV)] ratios > or = 8. The Th(IV) sulfato complex comprises both, monodentate and bidentate coordination, with Th-S distances of 3.81 +/- 0.02 and 3.14 +/- 0.02 Angstrom, respectively. A similar coordination is obtained for U(IV) sulfato complexes at pH 1 with monodentate and bidentate U-S distances of 3.67 +/- 0.02 and 3.08 +/- 0.02 Angstrom, respectively. By increasing the pH value to 2, a U(IV) sulfate precipitates. This precipitate shows only a U-S distance of 3.67 +/- 0.02 Angstrom in line with a monodentate linkage between U(IV) and sulfate. Previous controversially discussed observations of either monodentate or bidentate sulfate coordination in aqueous solutions can now be explained by differences of the [SO(4)(2-)]/[M] ratio. At low [SO(4)(2-)]/[M] ratios, the monodentate coordination prevails, and bidentate coordination becomes important only at higher ratios.     

A new synthetic route to Mg(2)Na(2)NiH(6) where a [NiH(4)] complex is for the first time stabilized by alkali metal counterions

Mg2Na2NiH6 was synthesized by reacting NaH and Mg2NiH4 at 310 degrees C under hydrogen pressure. The novel structure type was refined from neutron-diffraction data in the orthorhombic space group Pnma (No. 62), with unit cell dimensions of a = 11.428(2), b = 8.442(2), and c = 5.4165(9) Angstrom and a unit cell volume = 523 Angstrom(3) (Z = 4). The structure can be described by (Mg2H2)(2+) layers intersected by (Na2NiH4)(2-) layers. The [NiH4](4-) complex is approximately tetrahedral, indicating formal zerovalent nickel. This is the first example of a solid-state hydride where a [NiH4](4-) complex is directly stabilized by alkali metal ions instead of the more polarizing Mg(2+) ions. A rather long nickel-hydrogen bond distance of 1.65 Angstrom indicates a weaker Ni-H bond as a result of the weaker support from the less polarizing alkali metal counterions.     

Ln(14)Na(3)Ru(6)O(36) (ln = pr, nd): two new complex lanthanide-containing oxides of ruthenium

The lanthanide-containing ruthenium oxides Ln14Na3Ru6O36 (Ln = Pr, Nd) were prepared as single crystals from molten sodium hydroxide. The two compounds crystallize in the rhombohedral space group Rc with cell constants of a = 9.7380(2) and 9.6781(2) Angstrom and c = 55.5716(18) and 55.4156(18) Angstrom for Ln14Na3Ru6O36 (Ln = Pr, Nd), respectively. The structure of the two compounds is composed of two types of slabs that alternate in an AB fashion. Each slab consists of three layers and are arranged to yield a unit cell with a 12-layer structure. Both compounds exhibit magnetic behavior consistent with canted antiferromagnetism.     

Structure determination of novel orthoborate NaMgBO(3): a promising birefringent crystal

A novel orthoborate, NaMgBO(3), has been successfully synthesized by a standard solid-state reaction, and the crystal structure has been determined from powder X-ray diffraction data. It crystallizes in the monoclinic space group C2/c with lattice parameters a = 5.01313(6) Angstrom, b = 8.8007(1) Angstrom, c = 5.52831(7) Angstrom, and beta = 99.6962(6) degrees. Isolated [BO(3)](3-) anionic groups, which are the fundamental building units, are distributed perfectly parallel to each other. It is a typical structure of big birefringent crystals. The overall structure is similar to that of NaSrBO(3), which crystallizes in P2(1)/c. The correlation between these two structures is discussed. The Mg atoms in NaMgBO(3) are used instead of the position of Na in NaSrBO(3), while the Na atoms occupy the position of Sr. Then the directions of the BO(3) triangles are changed to balance the bond valence, which leads to a higher symmetry. They are the first pair of alkali-alkaline earth orthoborates with close space groups by exchange of the cation positions.     

Synthesis, X-ray crystal structure and X-band EPR of [Cu(H(2)O)(2)(imH)(4)] x Sq single crystals

The copper salt [Cu(H(2)O)(2)(imH)(4)] x Sq has been synthesized at room temperature. Crystal structure of the [Cu(H(2)O)(2)(imH)(4)] x Sq (Sq is squarete dianion (C(4)O(4)(2-)) and imH is imidazole (C(3)H(4)N(2))) complexes has been investigated by single-crystal X-ray diffraction analyses and the environment of copper ion has been identified by EPR. The single crystal is triclinic with the space group P1. The unit cell dimensions of the crystals are a=9.317 Angstrom, b=9.958 Angstrom, c=12.130 Angstrom, alpha=69.99 degrees , beta=76.61 degrees and gamma=78.13 degrees . The unit cell contains two molecules. The Cu(II) atom has an octahedral arrangement in which the Cu(II) ion lies on the inversion canter and is coordinated by four imidazole ligands with the equatorial plane and two water molecules with the octahedral axial. The complex shows a normal magnetic moment and the single crystal EPR spectra consist of two sets of four hyperfine lines of copper. The ground wave function of the hole of the Cu(2+) is an admixture of d(x(2) - y(2)) and d(z(2)) states.     

New 3-D La(III)-Cu(II)-containing coordination polymer with a high potential porosity

A new 3-D coordination polymer containing both 3d and 4f ions has been designed. Its chemical formula is La2[Cu(pba)]3(H2O)8 . 8H2O. It crystallizes in the quadratic system, space group I41/a with a = 42.4947(9) Angstrom, c = 16.3378(3) Angstrom, and Z = 16. Its crystal structure can be described as a 3-D molecular framework exhibiting a complex network of interconnected zigzaglike channels. Once crystallization water molecules are removed, this compound presents a high potential porosity and a low density. The porosity has been evaluated using Connolly's algorithm.     

Conformational analysis and crystal structure of {[1-(3-chloro-4-fluorobenzoyl)-4-fluoropiperidin-4yl]methyl}[(5-methylpyridin-2-yl)methyl]amine, fumaric acid salt

{[1-(3-Chloro-4-fluorobenzoyl)-4-fluoropiperidin-4yl]methyl}[(5-methylpyridin-2-yl)methyl]amine, fumaric acid salt (C(20)H(22)ClF(2)N(3)O, C(4)H(4)O(4)) (1) was synthesized and characterized by the complete (1)H, (13)C and (19)F NMR analyses. The conformation of the piperidin ring, in the solution state, was particularly studied from the coupling constants determined by recording a double-quantum filtered COSY experiment in phase-sensitive mode. (1)H NMR line-shape analysis was used, at temperatures varying between -5 and +60 degrees C, to determine the enthalpy of activation of the rotational barrier around the CN bond. Compound 1 crystallizes in the triclinic space group P1 with a=8.517(3) Angstrom, b=12.384(2) Angstrom, c=12.472(3) Angstrom, alpha=70.88(2) degrees, beta=82.04(2) degrees, gamma=83.58(2) degrees. The results strongly indicate that the solid and solution conformations are similar. Thermal stability and phases transitions were investigated by thermal gravimetric analysis (TGA) and differential scanning calorimetry (DSC). Furthermore polymorphism screening was studied from recrystallization of 1 performed in seven solvents and by slurry conversion in water. The X-ray powder diffraction (XRPD) and differential scanning calorimetry results suggested that 1 crystallizes into one crystalline form which melts at 157 degrees C (DeltaH=132 J g(-1)).