Nonlinear optical properties of strontium tartrato‐antimonate(III) dihydrate,Sr[Sb2{(+)‐C4H2O6}2]·2H2O

The tensor of nonlinear optical susceptibility for second harmonic generation [d^SHG _ijk ] of hexagonal (point group 6) strontium tartrato‐antimonate(III) dihydrate, Sr[Sb₂{(+)‐C₄H₂O₆}₂]·2H₂O, was determined using the Maker fringes method and a Nd:YAG laser with a wavelength of 1064 nm. The largest component of the tensor d^SHG ₃₃₃ amounts two times d^SHG ₁₁₁ of α‐quartz. Effective nonlinear optical susceptibility d^SHG _eff is given for phase matching type I for several wavelengths (for type II d^SHG _eff is nearly zero). The thermal stability of crystals of Sr[Sb₂{(+)‐C₄H₂O₆}₂]·2H₂O was determined in the temperature range from 153 K to 573 K by means of thermal expansion measurements and thermogravimetry. The temperature dependence of thermal expansion coefficients is given in the range from 153 K to 293 K. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)     

[CaSb2(EDTA)2(H2O)8]n: synthesis, crystal structure, and thermal behavior

The synthesis and crystal structure of a new EDTA complex, [CaSb₂(EDTA)₂(H₂O)₈]_n, are reported. This compound crystallizes in the monoclinic space group P2₁/n, with a = 7.132(1) Å, b = 21.893(3) Å, c = 10.891(2) Å, = 91.15(2)°. Sb(EDTA) entities are connected through carboxylate bridges to the calcium atoms resulting in layers parallel to the (101) plane. These layers are linked through a weak Sb···O bond (3.171 Å). Pyrolysis of this complex under sulfur vapor, between 400 and 800°C, leads to a mixture of the monometallic sulfides. Pyrolysis in air above 700°C allows the easy preparation of the mixed oxide CaSb₂O₆.     

Structural features of a new [Fe(nicotinamide)2(H2O)4]·[Fe(H2O)6]·(SO4)2·2H2O complex

A new nicotinamide complex of Fe(II) cation was prepared by reaction between ferrous sulfate and nicotinamide in aqueous solution. The complex was characterized on the basis of elemental analysis, FT IR and UV–VIS spectroscopy, electrochemistry (cyclic voltammetry) and X–ray crystallography. The complex consists of the molecular composition of [Fe(nicotinamide)₂(H₂O)₄]· [Fe(H₂O)₆]·(SO₄)₂·2H₂O. The complex crystallizes in the monoclinic space group P 2₁/c [a = 12.862(3), b = 7.110(3), c = 16.382(3) Å; β = 95.79(2)°]. It has been proven that nicotinamide is coordinated to Fe(II) through the nitrogen atom of its heterocyclic ring. © 2006 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim     

Structure,growth and optical properties of Zn0.24Ni0.76(SO4)·7H2O single crystal

A new crystalline complex zinc nickel sulfate heptahydrate (ZNSH) has been prepared. The crystal structure was investigated by x‐ray single crystal diffraction method and the empirical formula is Zn_0.24Ni_0.76(SO₄)·7H₂O. The ZNSH crystal belongs to the orthorhombic space group P2₁2₁2₁ with cell parameters a = 6.7742(14) Å, b = 11.748(2) Å, c = 12.009(2) Å. The deep‐green ZNSH single crystal with dimension of 30 × 25 × 25 mm³ has been grown by the cooling solution method. The constituent ratio of ZNSH crystal grown from various compounding solutions at temperature range 40‐50 °C is approximate invariant. The crystal absorption spectra with theoretical analysis are reported. (© 2004 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)     

Growth,structure, and superconducting properties of Bi2Sr2Ca2Cu3O10 and (Bi,Pb)2Sr2Ca2Cu3O10‐y crystals

Large and high‐quality single crystals of both Pb‐free and Pb‐doped high temperature superconducting compounds (Bi_1‐xPb_x)₂Sr₂Ca₂Cu₃O_10‐y (x = 0 and 0.3) were grown by means of a newly developed “Vapour‐Assisted Travelling Floating Zone” technique (VA‐TSFZ). This modified zone‐melting technique was realised in an image furnace and allowed for the first time to grow Pb‐doped crystals by compensating for the Pb losses occurring at high temperature. Crystals up to 3×2×0.1 mm³ were successfully grown. Post‐annealing under high pressure of O₂ (up to 10 MPa at T = 500°C) was undertaken to enhance T_c and improve the homogeneity of the crystals. Structural characterisation was performed by single‐crystal X‐ray diffraction (XRD) and the structure of the 3‐layer Bi‐based superconducting compound was refined for the first time. Structure refinement showed an incommensurate superlattice in the Pb‐free crystals. The space group is orthorhombic, A2aa, with cell parameters a = 27.105(4) Å, b = 5.4133(6) Å and c = 37.009(7) Å. Superconducting studies were carried out by A.C. and D.C. magnetic measurements. Very sharp superconducting transitions were obtained in both kinds of crystals (ΔT_c ≤ 1 K). In optimally doped Pb‐free crystals, critical temperatures up to 111 K were measured. Magnetic critical current densities of 2�10⁵ A/cm² were measured at T = 30 K and μ₀H = 0 T. A weak second peak in the magnetisation loops was observed in the temperature range 40‐50 K above which the vortex lattice becomes entangled. We have measured a portion of the irreversibility line (0.1‐5 Tesla) and fitted the expression for the melting of a vortex glass in a 2D fluctuation regime to the experimental data. Measurements of the lower critical field allowed to obtain the dependence of the penetration depth on temperature: the linear dependence of λ(T) for T < 30 K is consistent with d‐wave superconductivity in Bi‐2223. (© 2004 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)     

Linear Optical Properties of the Nonlinear Optical Calcium and Strontium Tartrato-Antimonates (III), Ca[Sb2 {(+) - C4H2O6}2] x2H2O and Sr[Sb2{(+) - C4H2O6}2 ] x2H2O

The study of nonlinear optical properties of crystals requires a thorough knowledge of the linear optical properties: knowledge of the transparency range is necessary, some information about the optical activity is useful. Above all, high quality refractive indices (with errors less than 10^-4) and their dispersion are the most important basic data, as they enable a detailed analysis of phase-matching conditions of nonlinear optical processes and an estimation of the nonlinear optical potential of a new non-centrosymmetric crystal. Such high quality refractive indices are also necessary in other areas of nonlinear optics, for example for the evaluation of nonlinear optical measurements like measurements of Maker fringes. In this short communication we present the linear optical basis for nonlinear optical investigations of the title compounds. The Sr compound has been known for a long time; its morphological crystallography is already presented in the famous Chemische Krystallographie by Paul Groth (1910). The Ca salt was first synthesized 1983 by one of us (L.B.).     

Synthesis and crystal structure of [Nd(H2O)2]2(C2O4)3

Some crystals of [Nd(H₂O)₂]₂(C₂O₄)₃ were synthesized hydrothermally by heating at 200°C for 8 days an aqueous suspension of neodymium oxalate decahydrate in presence of terephthallic acid and guanidinium carbonate. They crystallize in the orthorhombic system, space group P2₁2₁2₁, with a = 8.6702(7) Å, b = 9.558(2) Å, and c = 17.009(2) Å. The structure of this complex is built up by two independent neodymium atoms, three bischelating oxalate ligands, and four water molecules forming a rectangle building unit of 6-membered ring, [Ln(H₂O)₂(C₂O₄)]₆. The packing of these units leads to a layer parallel to the plane (001). However, the neodymium atoms of two neighbor layers share an edge of oxalato oxygen atoms thus giving a double-layer. The three dimensionality between these double-layers is insured by hydrogen bonds of water molecules which are bound to the neodymium atoms. There is no zeolitic water molecule. The two neodymium atoms are nine-coordinated. In both cases, the coordination polyhedron can be described as a distorted tricapped trigonal prism.     

Synthesis and crystal structure of [CuCl(phen)2]3H3V10O28 · 7 H2O

The new compound, [CuCl(phen)₂]₃H₃V₁₀O₂₈ · 7 H₂O, was prepared by reaction of an aqueous KVO₃ solution (pH 3) with an aqueous solution of CuSO₄ · 5 H₂O in which 1,10‐phenanthroline (phen) and KCl were added. The crystal structure of the compound was determined, and the proton position in H₃V₁₀O₂₈^3– were calculated by the bond length/bond number method and also determined from difference electron density map. The protons are bound to colinearly arranged μ–OV₂ and μ–OV₃ groups which is the common protonation type in trihydrogen decavanadates. The structure crystallizes in P1 space group symmetry. (© 2005 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)     

Crystal growth,crystal structure and physical properties of polar orthorhombic tris(glycine) zinc chloride

Large single crystals of the polar (point group mm 2) compound tris(glycine) zinc chloride, (NH₃CH₂COO)₃ · ZnCl₂, were grown from aqueous solutions. The refractive indices were measured in the wavelength region from 365 nm to 1083 nm and an unpolarised absorption spectrum was recorded (transparency range from 260 to 1550nm). The phase matching conditions for second harmonic generation were analysed: both, type I (ss‐f) and type II (sf‐f) are possible in the red and near IR region. All five components of the piezoelectric tensor [d_ijk ] were determined; the maximum values of longitudinal and transverse piezoelectric effects are less than one half of d₁₁₁ of α‐quartz. In addition, a redetermination of the crystal structure (including location of H atoms) is presented. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)     

Synthesis and crystal structure of a new inorganic – organic complex: (4‐ClC7H6NH3)9[Nd(P6O18)2]·9H2O

Single crystals of (4‐ClC₇H₆NH₃)₉[Nd(P₆O₁₈)₂]·9H₂O were synthesized in aqueous solution. This compound crystallizes in a triclinic P1 unit‐cell, with a = 14.898(6), b = 18.049(7), c = 20.695(6)Å, α = 102.04(3), β = 100.49(3), γ = 98.82(3)°, V = 5245(4) ų and Z = 2. The crystal structure has been solved and refined to R = 0.043 (Rw = 0.061) for 20420 observed reflections. The atomic arrangement of the title compound can be described as infinite layers built by complex of Neodyme [Nd(P₆O₁₈)₂] and nine water molecules. The organic cations are located in the space delimited by the successive inorganic layers. (© 2007 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)     

Electronic Structure of [Cu(C7H4NO3S)2(H2O)4] · 2H2O Crystal

The electronic absorption spectrum and ESR spectrum of the crystal of the title compound [Cu(C₇H₄NO₃S)₂(H₂O)₄] · 2 H₂O, are measured. The experimental results are discussed quantitatively by using the ligand field theory and the radial wave function of non-free Cu(II). The electronic structure of the compound is in agreement with its crystal structure.     

Synthesis and crystal structure of [Tb4(H2O)2](C2O4)2(C5H6O4)4

A terbium complex associating two ligands, oxalate and glutarate, was prepared under hydrothermal conditions at 200°C by treating an aqueous suspension of terbium oxalate decahydrate with glutaric acid and guanidinium carbonate. Its structure was solved by X-ray diffraction on a single crystal. It crystallizes in the monoclinic space group P2₁ with lattice constants, a = 9.514(1) Å, b = 9.0681(8) Å, c = 19.702(2) Å, and = 97.90(1)°. The terbium atoms and the oxalate ligands build dense chains which are connected by one side of the carboxylic group of some glutarate ligands, thus forming a sheet at the c level 0 and 1/2. These sheets are bridged by glutarate groups. The terbium atoms are ninefold coordinate with nine oxygen atoms of the ligands or with one water molecule and eight oxygen atoms of the ligands. Each polyhedron of the terbium atoms share one edge and one face of oxygen atoms with the two neighboring ones. The oxalate ligands are bischelating and bismonodentate. The coordination scheme of glutarate differs: either they are bismonodentate from one side and chelating and monodentate from the other side or they are chelating and monodentate from both sides.     

Crystal structure and electrochemical properties of the supramolecular compound [Himi]6[As2Mo18O62]·11H2O

A supramolecular compound, [Himi]₆[As₂Mo₁₈O₆₂]·11H₂O ( 1 ) (imi = imidazole), has been synthesized and characterized by single crystal X‐ray analysis, IR spectra, thermal gravimetric analysis, electrochemical and elemental analysis. The crystals are monoclinic, P 2(1)/n, a = 14.9529(8) Å, b = 20.9521(11) Å, c = 25.2464(13) Å, β = 93.8130(10)°, V = 7892.1(7) ų, Z = 4. X‐ray diffraction indicated that protonated imidazole cation and polyanion were linked together through electrostatic interactions and intermolecular forces (hydrogen bonding). (© 2007 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)     

Synthesis and crystal structure of [Cu2(NO3)4L2(BIPY)2 (H2O)3]·H2O (L = N,N′-bis(4-pyridylmethyl) isophthalamide

The synthesis and molecular structure of the title compound is reported. There are two different Cu atoms in separate chains which are linked to form double-stranded chains. Each Cu has a distorted octahedral coordination geometry. The structure has a triclinic space group P-1 with a = 11.0764(5), b = 15.9276(7), c = 18.2000(7) Å, V = 3197.9(2) ų, and Z = 2.     

[NaBi(EDTA)(H2O)3]n: synthesis, crystal structure, and thermal behavior

The synthesis and crystal structure of the EDTA complex [NaBi(EDTA)(H₂O)₃]_n are reported. It crystallizes in the monoclinic crystal system (space groupP2₁/c,a=6.822(1)Å,b=16.733(6)Å,c=13.763(2)Å, β=97.13(2)°). Bi(EDTA) entities are connected through carboxylate bridges resulting in layers parallel to the (010) plane. These layers are strongly linked by Na carboxylate and Na?OH₂ bridging interactions, establishing short Bi?Na and Na?Na distances. Pyrolysis of this complex under sulfur vapor between 600 and 900°C leads to the mixed sulfide NaBiS₂. Pyrolysis in air shows a very complicated decomposition mechanism and the probable formation of a bimetallic oxycarbonate.     

Crystal structure of [Pb(cis-anti-cis-dicyclohexyl-18-crown-6)(OH2)2][ClO4]2

[Pb(cis-anti-cis-dicyclohexyl-18-crown-6)(OH₂)₂][ClO₄]₂ was crystallized using a slightly modified literature method for the separation of dicyclohexyl-18-crown-6 isomers. It crystallizes in the monoclinic space groupP2₁/n witha=8.415(5),b=20.993(9),c=8.973(5) Å, β=111.56(6)^o, andD _calc=1.84 g/cm³ for Z=2. The Pb²⁺ ion resides on a crystallographic center of inversion and is coordinated to the six crown ether donors and two axial water molecules in a hexagonal bipyramidal geometry. The Pb-O(etheric) distances range from 2.694(4) to 2.743(4) Å while the Pb?OH₂ distance is 2.522(6) Å.     

Crystal and anion structure, TGA, DTA, and infrared and Raman spectra of managanese(II) nitroprusside dihydrate, Mn [Fe(CN)5NO]·2H2O

The single crystal and anion structure of Mn[Fe(CN)₅NO·2H₂O, obtained by slow interdiffusion of reactant solutions through a TMS gel, was solved by X-ray diffraction methods and refined toR1=0.036. Spatial group: orthorhombic,Pnma,a=14.069(2),b=7.538(1),c=10.543(1)Å,Z=4. The Mn(II) ion and the water molecules are sited on mirror planes, which bisect the nitroprusside ions. One of the water molecules is coordinated to Mn(II) and the other, strongly hydrogen (as acceptor) bonded to the first molecule. The IR spectrum confirms the bonding of the water molecules and TGA results are in accordance with the dihydrate character of the substance and its dehydration in two successive steps. DTA results and the Raman spectrum agree with other results and the comparison between IR and RamanvNO wavenumbers confirms the expected strong vibrational interaction between the closely packed antiparallel (eclipsed) NO groups. There is a topotactic relationship between the dihydrate and the trihydrate, which crystallizes in the space subgroupP2 _1/n.     

Crystal structure of [Mn2(III)(salpa)2Cl2(H2O)2] (H2salpa = 1-(salicylaldeneamino)-3-hydroxypropane)

The manganese complex, (Mn₂(III)(salpa)₂Cl₂(H₂O)₂], has been prepared and its structure determined using x-ray crystallography. The dimer is a di-₂-alkoxo complex which is a six-coordinate manganese dimer with unsupported alkoxide bridges and a rare example of a chloride- and water-containing manganese dimer. The complex crystallizes in the monoclinic space group P2₁/c with a = 9.315(5), b = 11.130(4), c = 11.637(5) Å, = 104.33(3)°, V = 1169.0(9) ų, and Z = 2. The structure comprises discrete binuclear clusters in which the metal atoms are bridged by two alkoxo oxygens of the salpa^2– ligands. The Mn—O and Mn—N distances are in good agreement with those found for other manganese(III) Schiff base complexes. The Mn—Cl and Mn—O3 distances are 2.585(2) and 2.371(2) Å, respectively, and the Mn ··· Mn distance is 3.001(1) Å. In the crystal, there are two types of hydrogen bonding between the H₂O molecule and the Cl atom with Cl ··· H(H₂O) distance of 2.33(6) (intramolecule: –1 + x, y, –1 + z) and 2.68(6) Å (intermolecule: –1 + x, 0.5–y, –0.5 + z).