Optical properties of non‐centrosymmetric mixed crystals K2(La1‐x Cex)(NO3)5 · 2 H2O (x = 0.0 – 1.0)

Large single crystals of optical quality of the non‐centrosymmetric orthorhombic potassium rare earth nitrate mixed crystals K₂(La_1–x Ce_x)(NO₃)₅ · 2 H₂O were grown at 38 °C from diluted HNO₃. For crystals with x = 0.0, 0.19, 0.38 and 0.66 refractive indices and their dispersion were determined with an error less than 1 · 10^–4 in the wavelength range 0.404 – 1.083 μm by the prism method. Phase matching conditions for collinear SHG frequency conversion were analysed in detail, including calculation of the effective nonlinear optical susceptibility. By an appropriate choice of the fraction x of cerium the mixed crystals K₂(La_1–x Ce_x)(NO₃)₅ · 2 H₂O allow an adjustment of non‐critical type I phase matching conditions to a desired wavelength of the fundamental wave within the range 1.055(4) – 1.107(6) μm. Non‐critical type II phase matching can be tuned in the wavelength range 0.949(2) – 0.931(2) μm. (© 2009 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)     

Kristallstrukturänderungen des Magnesiumnitrats-Hexahydrats,die infolge isodimorpher Substitution durch Co(II)- und Ni(II)-Ionen entstehen

The physico-chemical analysis data on the systems Mg(NO₃)₂ Co(NO₃)₂ H₂O and Mg(NO₃)₂ Ni(NO₃)₂ H₂O at 25.0°C have shown that due to isodimorphous substitution of Mg²⁺ in the crystals of Mg(NO₃)₂ · 6 H₂O for Co²⁺ or Ni²⁺, above a specific degree of ionic substitution, changes in the crystal structure of Mg(NO₃)₂ · 6 H₂O appear.     

Electron paramagnetic resonance of Gd3+ in Eu2Zn3(NO3)12·24H2O single crystals

Electron paramagnetic resonance of Gd³⁺ in Eu₂Zn₃(NO₃)₁₂·24H₂O single crystals is studied at ≈9.45 GHz and at 298 and 77 K. Gd³⁺ substitutes for the Eu³⁺ site. In addition to the allowed fine structure lines, forbidden transitions (ΔM = ±2,±3,±4,±5) are observed. The superposition model is applied to the zero‐field splitting parameter b₂⁰. (© 2004 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)     

Syntheses,Structures and Optical Properties of a Series of Lanthanide Complexes with Chelidamic Acid and 4,4′-Bipyridyl

Abstract  

The title complexes, (C₁₀H₈N₂)·[Y(C₇H₃NO₅)(C₇H₄NO₅)·2H₂O]·3H₂O (1), (C₁₀H₈N₂)·[Er(C₇H₃NO₅)(C₇H₄NO₅)·2H₂O]·3H₂O (2), (C₁₀H₈N₂)·[La(C₇H₃NO₅)(C₇H₄NO₅)·2H₂O]·4.5H₂O (3), (C₁₀H₈N₂)·[Sm(C₇H₃NO₅)(C₇H₄NO₅)·2H₂O]·4.75H₂O (4), (C₁₀H₈N₂)·[Pr(C₇H₃NO₅)(C₇H₄NO₅)·2H₂O]·4.75H₂O (5) were synthesized and characterized by X-ray single-crystal diffraction. The crystal structures of 1–2 reveal that they are isomorphous, among which the metal atoms are all eight-coordinate with a distorted dodecahedron coordination geometry. The structures of 3–5 are isomorphic, among which the metal atoms are all nine-coordinate with distorted tricapped trigonal prismatic coordination geometries by two chelidamic acid ligands. Complexes 1–5 are formed into 3D networks by H-bonds. The optical properties of 1–5 were investigated in terms of fluorescent spectra, which all exhibit strong luminescence.     

A Unique Example of a Co-crystal of [Co(AMTTO)2(H2O)2](NO3)2 and [Co(AMTTO)2(CH3CN)2](NO3)2 (AMTTO = 4-amino-5-methyl-1,2,4-triazol-3(2H)-thione)

A co-crystal of cobalt(II) complexes, Co(AMTTO)₂(CH₃CN)₂]²⁺(NO₃)₂. [Co(AMTTO)₂(H₂O)₂]²⁺(NO₃)₂, compound (1) was isolated from the reaction of Co(NO₃)₂?6H₂O and 4-amino-3-mercapto-6-methyl-5-oxo-1,2,4-triazine (AMTTO) in acetonitrile as solvent. Isolated crystals were characterized by elemental analyses, IR spectroscopy as well as X-ray diffraction studies. Crystal data for 1 at 95 K revealed a monoclinic space group P2₁/n, a?=?11.7903(5), b?=?12.1279(5), c?=?14.1443(6) Å, β?=?99.244(4)°, Z?=?2, R₁?=?0.0339. Compound 1 consists of two co-crystallized Co(II) complexes [Co(AMTTO)₂(CH₃CN)₂]²⁺ and [Co(AMTTO)₂(H₂O)₂]²⁺ and four nitrate counter anions In both complexes, cobalt(II) ions are in an octahedral arrangement. Two S, N bidentate AMTTO ligands are coordinated to both Co(II) ions. The coordination sphere of Co1 is completed by two acetonitrile molecules, and these positions are occupied by water molecules for Co2.

Graphic Abstract

A co-crystal of cobalt(II) compound was isolated from the reaction of Co(NO₃)₂?6H₂O and 4-amino-3-mercapto-6-methyl-5-oxo-1,2,4-triazine in acetonitrile as solvent.

     

Synthesis and crystal structures of nitratocobaltates Na2[Co(NO3)4], K2[Co(NO3)4], and Ag[Co(NO3)3] and potassium nitratonickelate K2[Ni(NO3)4]

The cobalt(II) and nickel(II) nitrate complexes with an island structure (Na₂[Co(NO₃)₄] (I) and K₂[Co(NO₃)₄] (II)] and a chain structure [Ag[Co(NO₃)₃] (III) and K₂[Ni(NO₃)₄] (IV)] are synthesized and investigated using X-ray diffraction. In the anionic complex [Co(NO₃)₄]^2? of the crystal structure of compound I, the Co coordination polyhedron is a twisted tetragonal prism formed by the O atoms of four asymmetric bidentate nitrate groups. In the anion [Co(NO₃)₄]^2? of the crystal structure of compound II, one of the four NO₃ groups is monodentate and the other NO₃ groups are bidentate (the coordination number of the cobalt atom is equal to seven, and the cobalt coordination polyhedron is a monocapped trigonal prism). The crystal structures of compounds III and IV contain infinite chains of the compositions [Co(NO₃)₂(NO₃)_2/2]^? and [Ni(NO₃)₃(NO₃)_2/2]^2?, respectively. In the crystal structure of compound III, seven oxygen atoms of one monodentate and three bidentate nitrate groups form a dodecahedron with an unoccupied vertex of the A type around the Co atom. In the crystal structure of compound IV, the octahedral polyhedron of the Ni atom is formed by five nitrate groups, one of which is terminal bidentate. The data on the structure of Co(II) coordination polyhedra in the known nitratocobaltates are generalized.     

Crystal Structure of [Co(NH3)5NO3](NO3)(PF6)?·?1.5H2O and the Vibrational Bands of its Normal and 15NO3-Enriched Cation

The crystal structure of [Co(NH₃)₅NO₃](NO₃)(PF₆) ·1.5 H₂O was studied by X-ray diffraction methods in order to obtain the unknown molecular structure of the [Co(NH₃)₅NO₃]²⁺ cation . The substance crystallizes in the monoclinic system, space group C2/m, with a = 18.6231(6) ?, b = 7.8757(3) ?, c = 9.6434(3) ? and β = 95.484(2)°. An infrared and Raman study of the bromide salt was also performed and the spectra interpreted with the aid of ¹⁴NO₃/¹⁵NO₃ isotopic replacement and quantum chemistry calculations. E.L. Varetti — Member of the Carrera del Investigador Científico, CONICET, R. Argentina     

Specific features of twinning in divalent nitrates

The etch patterns similar to those found previously for strontium nitrate Sr(NO₃)₂ were revealed on the surface of barium nitrate Ba(NO₃)₂ and lead nitrate Pb(NO₃)₂. The geometry of these patterns is studied. It is suggested that these etch patterns correspond to the translation twins occurring in divalent nitrates at the Pm3 → Pa3 phase transition.     

Synthesis, Crystal Structure of a New Co(II) Complex with Pyrazine-2,3,5,6-tetracarboxylic Acid

Abstract A new complex [Co(H₂pztc)(bpy)H₂O] (H₄pztc = pyrazine-2,3,5,6-tetracarboxylic acid, bpy = 2,2′-bipyridine) has been synthesized by hydrothermal reactions of Co(NO₃)₂ · 6H₂O with H₄pztc and bpy and characterized by IR and X-ray diffraction single crystal structure analysis. It belongs to monoclinic system, P2₁/c space group with a = 13.454(2) ?, b = 12.939(2) ?, c = 11.4993(19) ?, α = 90°, β = 111.640(3)°, γ = 90°. This complex is assembled into 3D supramolecular architecture by hydrogen bonds (O–H···O, C–H···O). Index Abstract A new complex of cobalt(II) with pyrazine-2,3,5,6-tetracarboxylic acid and 2,2′-bipyridine is assembled by intermolecular hydrogen bonds forming 2D layer and 3D supramolecular network.      

Facile and one-pot synthesis of magnetic nanoparticles containing mesoporous carbon

Abstract

Magnetic nanoparticles containing mesoporous carbon materials have been synthesized via an one-pot strategy associated with a direct carbonization process from resol, metal ion sources (Co(NO₃)₂·6H₂O, Ni(NO₃)₂·6H₂O) and triblock copolymer F127. The samples exhibited well-ordered 2-dimensional (2-D) hexagonal mesostructures with p6mm symmetry. The Brunauer-Emmet-Teller (BET) surface area and pore size 1.0wt%Co- and 1.0wt%Ni-FDU-15(700) with 1.0?wt% Co and 1.0?wt% Ni content were 700, 528 m²/g and 17.2, 36.4 Å, respectively, after carbonization at 700?°C. The saturation magnetization values of 1.0wt%Co- and 1.0wt%Ni-FDU-15(700) after carbonization at 700?°C were 1.3 and 1.0?emu/g, respectively.     

pH‐Controlled topologies of two Co(II) complexes based on 5‐Nitro‐1,2,3‐benzenetricarboxylic acid and 1,6‐Bis(1,2,4‐triazole‐1‐yl)hexane

Two new Co(II) coordination polymers, [Co(Hnbta)(bth)]_n ( 1 ) and {[Co₃(nbta)₂(bth)₃(H₂O)]·H₂O}_n ( 2 ), (H₃nbta = 5‐nitro‐1,2,3‐benzenetricarboxylic acid and bth = 1,6‐bis(1,2,4‐triazole‐1‐yl)hexane), have been synthesized under different pH values through hydrothermal reactions. Both complexes were characterized by elemental analysis, IR spectra, thermogravimetric analysis (TGA), and single‐crystal X‐ray crystallography. Complex 1 exhibits a 3D polythreaded network based on 4‐connected sql 2D layer. Complex 2 has a (4,4,5)‐connected trinodal 3D pillar‐layered network with a (4²·6⁴)₂(4²·6⁷·8)₂(6⁴·8²) topology. Magnetic susceptibility measurements indicate that complexes 1 and 2 show weak antiferromagnetic interactions between the adjacent Co(II) ions.     

Crystallization of PbxSr1‐x(NO3)2 Solid Solutions from Aqueous Solutions

A series of Pb_xSr_1‐x(NO₃)₂ crystals have been grown from aqueous solutions and characterized by X‐ray powder diffraction. All diffraction data were well indexed according to the simple cubic structure. The variation of lattice constants with the concentrations of Pb²⁺ in the crystals accorded quite well to the Vegard's Law. The composition of the Sr(NO₃)₂ crystal doped with Pb²⁺ was studied by electron microprobe and it was found that Pb²⁺ was enriched in the 111 sectors. Equilibrium behavior in the Pb(NO₃)₂‐Sr(NO₃)₂‐H₂O system was analyzed by Lippmann's phase diagram and the equilibrium distribution coefficient D_Pb=133.6. This large value of D indicates that Pb²⁺ ion is preferentially distributed to the solid phase.     

Syntheses and Structural Characterization of Three New Alkaline Earth Metal Supramolecular Coordination Compounds Based on Atza Ligand (Atza = 5<Emphasis Type="Bold">-</Emphasis>Aminotetrazole<Emphasis Type="Bold">-</Emphasis>1<Emphasis Type="Bold">-</Emphasis>Acetato Anion)

Abstract  

Reactions of alkaline earth metal salts M(NO₃)₂ (M = Mg, Ca, Sr) and ligands 5-aminotetrazole-1-acetic acid (Hatza) in water/methanol solution, respectively, produced three new complexes [Mg(atza)₂(H₂O)₄] (1), [Ca(atza)₂(H₂O)₄] (2) and [Sr(atza)₂(H₂O)₃]^.2H₂O (3). These compounds were structurally characterized by elemental analysis, IR spectroscopy and single-crystal X-ray diffraction. Compounds 1 and 2 have a mononuclear structure and the same coordination mode. Compound 3 has a 1D polymeric chain structure. In 1–3, amido group (–NH₂) of atza ligand forms hydrogen bond N(5)–H(5)···N(O) with the neighboring carboxylate-O, tetrazolate-N or water molecule which stabilized the supramolecular assemblies.     

Crystal structure of strontium aqua(ethylenediaminetetraacetato)cobaltate(II) tetrahydrate Sr[CoEdta(H2O)] · 4H2O

The complex Sr[Co^II Edta] · 5H₂O (I) (where Edta ^4? is the ethylenediaminetetraacetate ion) has been synthesized. The crystal structure of this compound is determined by X-ray diffraction. Crystals are monoclinic, a = 7.906(2) Å, b = 12.768(2) Å, c = 18.254(3) Å, β = 95.30(3)°, V = 1834.8 ų, space group P2₁/n, Z = 4, and R = 0.036. The structure is built up of the binuclear complex fragments {Sr(H₂O)₃[CoEdta(H₂O)]}, which consist of the anionic [CoEdta(H₂O)]^2? and cationic [Sr(H₂O)₃]²⁺ units linked by the Sr-O bonds into a three-dimensional framework. The coordination polyhedra of the Co and Sr atoms are mono-and bicapped trigonal prisms. The coordination sphere of the Co atom (the coordination number is equal to 6 + 1) involves six donor atoms (2N and 4O) of the Edta ^4? ligand and the O_w atom of water molecule. One of the Co-O distances (2.718 Å) is considerably longer than the other Co-O_lig distances (2.092–2.190 Å) and the Co-O_w(1) distance (2.079 Å). The Sr coordination polyhedron (the coordination number is eight) contains three water molecules, three carbonyl O atoms of the three different anionic complexes, and two O atoms of one acetate group of the fourth anionic complex. The Sr-O distances fall in the range 2.535–2.674 Å. The structural formula of the compound is {Sr(H₂O)₃[CoEdta(H₂O)]}_3∞ · H₂O.     

Crystal structure of an unusual four-coordinated copper(II) complex containing 1,10-o-phenanthroline and salicyclic acid crystal structure containing Cu(II) o-phen and salicyclic acid

We have synthesized a multi-ligand chelate copper(II) complex [Cu · (C₇H₅O₃] · (C₁₂H₈N₂) · H₂O₁ · (C₇H₆O₃)· NO₃, and determined its structure by X-ray diffraction method. The space group of the title compound is P2₁/a. It is monoclinic, with a = 14.227(4), b = 9.627(4), c = 19.008(7) Å, β = 102.06(3)·, Z = 4. The two salicyclic acid molecules in the cell are in different environments, one inner, the other outer. The geometry around Cu(II) is a four-coordinated distorted plane square. The two coordinating atoms are two nitrogen atoms from phenanthroline, one oxygen atom from salicyclic acid, one oxygen atom from water.     

3D Solid-State Network from Hierarchical Supramolecular Self-Assembly of Transition Metal Complexes of Pyridine Based Ligand

Abstract  The crystal structures of [Cu(py)₄(ClO₄)](ClO₄) (1), [V(pic)₂(OH)](NO₃)₂ · H₂O (2) and [Ni(H₂O)₆][Ni(dpa)₂] · 2H₂O (3) [py = Pyridine, picH = Pyridine-2-carboxylic acid, dpaH₂ = Pyridine-2,6-dicarboxylic acid] was determined by single-crystal X-ray diffraction techniques. Solid-state structural analysis shows that all these complexes from extensive 3D network structure via supramolecular self-assembly. The crystal structures are stabilized by extended hydrogen bonding interactions. The complex 2 forms orange V₂O₅ micro spheroids when heated at ~400 °C for 6 h. Graphical Abstract  Hierarchical supramolecular self-assembly of transition metal complexes of pyridine based ligands in crystal. Electronic supplementary material  The online version of this article (doi:) contains supplementary material, which is available to authorized users.     

Cover Picture: Cryst. Res. Technol. 10/2009

The cover picture shows a single crystal of K₂La(NO₃)₅ · 2 H₂O grown at 38 °C from diluted HNO₃. View approximately along the polar –<$>\vec a_3<$> axis of the crystal. (see pages 1131 – 1138) (© 2009 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)     

A new nonlinear optical crystal: Bi2O2(OH)(NO3)

The nonlinear optical (NLO) properties of Bi₂O₂(OH)(NO₃) crystals have been reported for the first time. Bi₂O₂(OH)(NO₃) crystals with dimensions of 1.3×1.2×0.1 mm³ have been grown by hydrothermal method, and the crystals characterized by X‐ray powder diffraction (XRD), SEM and IR. The measured second harmonic generation (SHG) effect of Bi₂O₂(OH)(NO₃) was about 7 times that of KDP. The mechanism responsible for the large SHG of Bi₂O₂(OH)(NO₃) was explained according to its structure. (© 2011 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)     

Spin‐Hamiltonian parameters for Dy3+ ion at the trigonal 12‐fold coordinated La3+ site of La2Mg3(NO3)12·24H2O

The spin‐Hamiltonian parameters (g factors g_‖, g_⊥ and hyperfine structure constants ¹⁶¹A_‖, ¹⁶¹A_⊥, ¹⁶³A_‖, ¹⁶³A_⊥) for ¹⁶¹Dy³⁺ and ¹⁶¹Dy³⁺ isotopes in the trigonal 12‐fold coordinated La³⁺ site of La₂Mg₃(NO₃)₁₂·24H₂O crystal are calculated from a diagonalization (of energy matrix) method. In the method, the Zeeman and hyperfine interaction terms are added to the conventional Hamiltonian used in the studies of crystal‐field energy levels, and a 66×66 energy matrix concerning the ground multiplet ⁶H_15/2 and the first to fifth excited multiplets ⁶H_13/2, ⁶H_11/2, ⁶H_9/2, ⁶H_7/2 and ⁶H_5/2 are applied. The calculated results are discussed. (© 2010 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)     

Syntheses,crystal structures and properties of Cd(II) and Ag(I) complexes based on 2-p-methylphenyl-5-(2-pyridyl)-1,3,4-thiadiazole

Abstract

Complexes of [CdL₂(NO₃)₂]·1.5H₂O and [Ag₂(μ-L)₂(NO₃)₂] were synthesized by the reactions of 2-p-methylphenyl-5-(2-pyridyl)-1,3,4-thiadiazole (L) with Cd(NO₃)₂·4H₂O and AgNO₃, respectively. Their structures were determined by single crystal X-ray diffraction. The photophysical property and thermal stability were characterized by FT???IR, UV???Vis absorption, fluorescence, and thermogravimetric analysis (TGA). Both complexes belong to the triclinic system with space group p???1. The central metal of [CdL₂(NO₃)₂]·1.5H₂O has a distorted octahedral geometry [CdN₄O₂], while two central Ag(I) atoms of [Ag₂(μ-L)₂(NO₃)₂] exhibit distorted tetrahedral geometries [AgN₃O].