An Old Crystallization Technique as a Fast, Facile, and Adaptable Method for Obtaining Single Crystals of Unstable "LiTCNQF" and New Compounds of TCNQ or TCNQF: Syntheses, Crystal Structures, and Magnetic Properties.

Detailed structural information is essential for understanding the properties of TCNQ and TCNQF compounds (TCNQ = 7,7,8,8-tetracyanoquinodimethane; TCNQF = 2,3,5,6-tetrafluoro-7,7,8,8-tetracyanoquinodimethane). The ineludible requirement of obtaining crystals of a size and quality sufficient to yield a successful X-ray diffraction analysis has been challenging to satisfy because of the instability of many of these compounds in solution. Crystals of two new complexes of TCNQ, [-M(2)(TCNQ)] [M = Ni (), Zn (); 2ampy = 2-aminomethylpyridine], as well as unstable [Li(TCNQF)(CHCN)]·CHCN (), can be prepared in minutes by a horizontal diffusion technique and can be harvested easily for X-ray structural studies.

-{Er } complex showing field supported slow magnetic relaxation.

The -{Er} complex [ErCl()(OH)(HO)]Cl·HO ( = 9.4; H() = -vanillin) (1) was generated by an method. The isolated Er(iii) complex 1 was characterized by elemental analysis and molecular spectroscopy.

Slow magnetic relaxation in Ni-Ln (Ln = Ce, Gd, Dy) dinuclear complexes.

Three new isomorphous complexes [Ni(o-van-en)LnCl(HO)] [H(o-van-en) = N,N'-ethylene-bis(3-methoxysalicylaldiminate; Ln = Ce (1), Gd (2), Dy (3)] were prepared by a stepwise reaction using mild conditions and were structurally characterised as dinuclear molecules in which Ni and Ln are coordinated by the compartmental Schiff base ligand (o-van-en) and doubly bridged by O atoms. While the nickel(ii) centre is diamagnetic within the NO square-planar coordination of the Schiff base ligand, the lanthanide atoms are octa-coordinated to give an {LnClO} chromophore with a fac-arrangement of the chlorido ligands. AC magnetic measurements revealed that all three complexes, including the nominally isotropic Gd(iii) system, show field induced slow magnetic relaxation with two or three relaxation channels: at T = 1.

Polymorphism of the dinuclear Co-Schiff base complex [Co(o-van-en)]·4CHCN (o-van-en is a salen-type ligand).

Reactions of Co(OH) with the Schiff base bis(2-hydroxy-3-methoxybenzylidene)ethylenediamine, denoted H(o-van-en), under different conditions yielded the previously reported complex aqua[bis(3-methoxy-2-oxidobenzylidene)ethylenediamine]cobalt(II), [Co(CHNO)(HO)], 1, under anaerobic conditions and two polymorphs of [μ-bis(3-methoxy-2-oxidobenzylidene)ethylenediamine]bis{[bis(3-methoxy-2-oxidobenzylidene)ethylenediamine]cobalt(III)} acetonitrile tetrasolvate, [Co(CHNO)]·4CHCN, i.e. monoclinic 2 and triclinic 3, in the presence of air.

Exceptionally slow magnetic relaxation in cobalt(ii) benzoate trihydrate.

Cobalt(ii) benzoate trihydrate prepared by the reaction of CoCO with benzoic acid (HBz) in boiling water followed by crystallization has been structurally characterized as a chain-like system with the formula unit [Co(Bz)(HO)]Bz·HO where the Co(ii) atoms are triply linked by one bridging syn-syn benzoato (Bz) and two aqua ligands; additional benzoate counter ions and solvate water molecules are present in the crystal structure. DC magnetic measurements reveal a sizable exchange coupling of a ferromagnetic nature between the Co(ii) atoms. At T = 5.

Disorder of the dimeric TCNQ-TCNQ unit in the crystal structure of [Ni(bpy)](TCNQ-TCNQ)(TCNQ)·6HO (TCNQ is 7,7,8,8-tetra-cyano-quinodi-methane).

Crystallization from an aqueous methanol system composed of Ni(NO), 2,2'-bipyridine (bpy) and LiTCNQ (TCNQ is 7,7,8,8-tetra-cyano-quinodi-methane) in a 1:3:2 molar ratio yielded single crystals of bis-[tris-(2,2'-bi-pyridine-κ,')nickel(II)] bis-(7,7,8,8-tetra-cyano-quinodi-methane radical anion) bi[7,7,8,8-tetra-cyano-quino-dimethanide] hexa-hydrate, [Ni(CHN)](CHN)(CHN)·6HO or [Ni(bpy)](TCNQ-TCNQ)(TCNQ)·6HO. The crystal structure comprises [Ni(bpy)] complex cations, two centrosymmetric crystallographically independent TCNQ anion radicals with π-stacked exo groups, and an additional dimeric TCNQ-TCNQ unit which comprises 75.3 (9)% of a σ-dimerized (TCNQ-TCNQ) dianion and 24.

Synthesis, crystal structure and magnetic properties of (acetato-κ²O,O')bis(5,5'-dimethyl-2,2'-bipyridine-κ²N,N')nickel(II) perchlorate monohydrate.

The title hydrated ionic complex, [Ni(CH3COO)(C12H12N2)2]ClO4·H2O or [Ni(ac)(5,5'-dmbpy)2]ClO4·H2O (where 5,5'-dmbpy is 5,5'-dimethyl-2,2'-bipyridine and ac is acetate), (1), was isolated as violet crystals from the aqueous ethanolic nickel acetate-5,5'-dmbpy-KClO4 system. Within the complex cation, the Ni(II) atom is hexacoordinated by two chelating 5,5'-dmbpy ligands and one chelating ac ligand. The mean Ni-N and Ni-O bond lengths are 2.

Synthesis, characterization and crystal structure of the new pentahydrate of bis(2,2'-bipyridine-κ(2)N,N')(oxalato-κ(2)O(1),O(2))nickel(II).

The reaction of NiCl2, K2C2O4·H2O and 2,2'-bipyridine (bpy) in water-ethanol solution at 281 K yields light-purple needles of the new pentahydrate of bis(2,2'-bipyridine)oxalatonickel(II), [Ni(C2O4)(C10H8N2)2]·5H2O or [Ni(ox)(bpy)2]·5H2O, while at room temperature, deep-pink prisms of the previously reported tetrahydrate [Ni(ox)(bpy)2]·4H2O [Román, Luque, Guzmán-Miralles & Beitia (1995), Polyhedron, 14, 2863-2869] were gathered. The asymmetric unit in the crystal structure of the new pentahydrate incorporates the discrete molecular complex [Ni(ox)(bpy)2] and five solvent water molecules. Within the complex molecule, all three ligands are bonded as chelates.

Crystal structure and thermal properties of a square-planar Ni(II) complex of cyanide and a tricyclic bis-amidine ligand formed in situ under solvothermal conditions.

The reaction of N(1),N(1')-(ethane-1,2-diyl)bis(propane-1,3-diamine) (bapen), K2[Ni(CN)4]·H2O and dimethylformamide in the presence of Gd(NO3)3·6H2O under solvothermal conditions yielded yellow crystals of dicyanido(2,3,4,6,7,9,10,11-octahydropyrimido[2',1':3,4]pyrazino[1,2-a]pyrimidine)nickel(II) hemihydrate, [Ni(CN)2(C10H16N4)]·0.5H2O, (I), the crystal structure of which is composed of [Ni(CN)2(pdpm)] molecules (pdpm is 2,3,4,6,7,9,10,11-octahydropyrimido[2',1':3,4]pyrazino[1,2-a]pyrimidine) on general positions linked by O-H···N hydrogen bonds to water molecules located on twofold axes. This structural unit is further linked by nonclassical C-H···N interactions to form a warped two-dimensional net perpendicular to the unit-cell b axis.

Thermal decomposition of [Co(en)3][Fe(CN)6]∙ 2H2O: Topotactic dehydration process, valence and spin exchange mechanism elucidation.

Background: The Prussian blue analogues represent well-known and extensively studied group of coordination species which has many remarkable applications due to their ion-exchange, electron transfer or magnetic properties. Among them, Co-Fe Prussian blue analogues have been extensively studied due to the photoinduced magnetization. Surprisingly, their suitability as precursors for solid-state synthesis of magnetic nanoparticles is almost unexplored.

Di-μ-hydroxido-bis-[hemiaqua-(N,N,N',N'-tetra-methyl-ethane-1,2-diamine)-copper(II)] bis-(tetra-fluoridoborate).

The title compound, [Cu(2)(OH)(2)(C(6)H(16)N(2))(2)(H(2)O)](BF(4))(2), consists of dinuclear centrosymmetric [Cu(2)(OH)(2)(tmen)(2)(H(2)O)](2+) complex cations (tmen = N,N,N',N'-tetra-methyl-ethane-1,2-diamine) and tetra-fluoridoborate anions. In the cation, the Cu(II) atom shows a slightly distorted square-pyramidal coordination geometry provided by a pair of μ-OH(-) anions and by the N atoms of a chelate tmen ligand in the basal plane. The apical position is statistically occupied by the O atom of a half-occupancy water mol-ecule.

The chain structure of [Ni(C(4)H(2)O(4))(C(12)H(8)N(2))(H(2)O)](n) with different types of fumarate bridging.

Using modified solvothermal conditions (longer cooling time), beside previously characterized dark-green crystals of [Ni(C(4)H(2)O(4))(C(12)H(8)N(2))] (main product), a few light-green crystals of the polymeric title compound, catena-poly[[aqua-(1,10-phenanthroline-κ(2)N,N')nickel(II)]-μ-fumarato-κ(2)O:O'-[aqua-(1,10-phenanthroline-κ(2)N,N')nickel(II)]-μ-fumarato-κ(4)O,O':O'',O'''], [Ni(C(4)H(2)O(4))(C(12)H(8)N(2))(H(2)O)](n) were isolated. Its crystal structure is made up from zigzag chains, propagating in [001], in which the Ni(2+) ions are linked alternatively by μ(2)-fumarato and bis-chelating fumarato bridging ligands. The Ni(2+) ion is coordinated in a deformed octa-hedral geometry by one chelating 1,10-phenanthroline ligand, one aqua ligand in a cis position with regard to both N-donor atoms and by two different fumarato ligands, each residing with its central C=C bond on an inversion centre, occupying the remaining coordination sites in a fac fashion.

Tris(1,2-diamino-ethane)-nickel(II) hexa-fluoridosilicate.

The ionic title complex, [Ni(C(2)H(8)N(2))(3)](SiF(6)), is built up of [Ni(en)(3)](2+) complex cations (en = 1,2-diamino-ethane) and hexa-fluoridosilicate anions. Single crystals of the title complex were isolated from an aqueous-ethano-lic Ni(2+)-en-SiF(6) (2-) system. The Ni(II) and Si atoms are each located on a special position with site symmetry 3.

Redetermination of aqua-(dihydrogen ethyl-enediamine-tetra-acetato-κO,O',N,N',O'')nickel(II).

The crystal structure of the title compound, [Ni(C(10)H(14)N(2)O(8))(H(2)O)] or [Ni(H(2)edta)(H(2)O)] (H(4)edta is ethyl-ene-diamine-tetra-acetic acid), originally determined by Smith & Hoard [J. Am. Chem.

catena-Poly[[[diaqua-(di-2-pyridylamine-κN,N')nickel(II)]-μ-fumarato-κO:O] tetra-hydrate].

In the crystal structure of the title compound, {[Ni(C(4)H(2)O(4))(C(10)H(9)N(3))(H(2)O)(2)]·4H(2)O}(n), zigzag chains are built up from cis-[Ni(dpya)(H(2)O)(2)](2+) cations (dpya is di-2-pyridylamine) linked by bis-monodentate coordinated bridging fumarate ligands. The Ni(II) atom is coordinated by one chelating dpya ligand, two aqua ligands in trans positions and two monodentate fumarate ligands in cis positions in the form of a deformed octa-hedron. The water mol-ecules, O atoms of the fumarate carboxyl-ate groups and the amine group of the dpya ligand are involved in an extended network of intra- and inter-molecular O-H⋯O hydrogen bonds.

Bis(di-2-pyridylamine-kappa2N2,N2')(nitrato-kappa2O,O')nickel(II) nitrate.

In the ionic title compound, [Ni(NO(3))(C(10)H(9)N(3))(2)]NO(3), the central Ni(II) atom exhibits cis-NiN(4)O(2) octahedral coordination with three chelating ligands, viz. one nitrate anion and two di-2-pyridylamine (dpya) molecules. A second nitrate group acts as a counter-ion.

Two different one-dimensional structural motifs in [catena-{Cu(tacn)}2Pd(CN)4]Br2.[catena-Cu(tacn)Pd(CN)4]2.H2O (tacn is 1,4,7-triazacyclononane).

The title compound, catena-poly[[bis[(triazacyclononane-kappa(3)N,N',N'')copper(II)]-di-mu-cyanido-kappa(4)N:C-palladate(II)-di-mu-cyanido-kappa(4)C:N] dibromide bis[[(triazacyclononane-kappa(3)N,N',N'')copper(II)]-mu-cyanido-kappa(2)N:C-[dicyanidopalladate(II)]-mu-cyanido-kappa(2)C:N] monohydrate], {[Cu(2)Pd(CN)(4)(C(6)H(15)N(3))(2)]Br(2).[Cu(2)Pd(2)(CN)(8)(C(6)H(15)N(3))(2)].H(2)O}(n), (I), was isolated from an aqueous solution containing tacn.

Bis(2,2'-bipyridine-κN,N')(maleato-κO,O)nickel(II) 7.34-hydrate.

The title compound, [Ni(C(4)H(2)O(4))(C(10)H(8)N(2))(2)]·7.34H(2)O, was obtained by crystallization from an aqueous ethano-lic reaction mixture containing nickel(II) acetate, maleic acid, bipyridine, sodium hydroxide and ammonia. The asymmetric unit contains one independent complex mol-ecule and 7.

Tris(propane-1,2-diamine-κN,N')nickel(II) tetra-cyanidonickelate(II).

The title compound, [Ni(C(3)H(10)N(2))(3)][Ni(CN)(4)], is built up of [Ni(pn)(3)](2+) cations (pn is 1,2-diamino-propane) and [Ni(CN)(4)](2-) anions. Both Ni(II) atoms in the cation and the anion lie on a mirror plane. The respective ions inter-act through Coulombic forces and through a complex network of hydrogen bonds.

Ammonium bis(tetraethylammonium) hexacyanidoferrate(III) trihydrate.

In the structure of the title salt, (NH(4))(C(8)H(20)N)(2)[Fe(CN)(6)].3H2O, the O atom of one of the water molecules shares its crystallographic site with the N atom of the ammonium cation in a 1:1 ratio. The second O atom from the two crystallographically independent water molecules is disordered over two positions separated by 0.

Magneto-structural correlations in Cu(tn)Cl2 (tn = 1,3-diaminopropane): two-dimensional spatially anisotropic triangular magnet formed by hydrogen bonds.

A novel polymeric one-dimensional compound Cu(tn)Cl2 (tn = 1,3-diaminopropane) was prepared and structurally characterized, and its spectral, magnetic, thermodynamic, and thermal properties were studied. The unique structure shows ladderlike chains composed of Cu(II) atoms and chloro bridging ligands [Cu(-mu(3)-Cl-)Cu2] running along the crystallographic c axis. The coordination geometry about copper (4 + 2) approximates that of a strongly elongated octahedron.

Modulated one-dimensional structure of [Cd(NH3)3Ni(CN)4].

The crystal structure of [Cd(NH(3))(3)Ni(CN)(4)] has been solved and refined as an incommensurate structure in four-dimensional superspace. The Xcalibur point-detector diffractometer was used for data collection up to the third-order satellites. The structure was refined from 3496 observed reflections to a final R value of 0.

2-(Acridin-9-ylimino)-3-dimethylamino-1,3-thiazolidin-4-one.

In the title compound, C18H16N4OS, prepared by the reaction of 4-(acridin-9-yl)-1,1-dimethylthiosemicarbazide with methyl bromoacetate, the acridine and thiazolidine ring systems are both non-planar and, because of steric requirements, almost perpendicular, with a dihedral angle between their planes of 99.69 (6) degrees. C-H.