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Complex Anion (complex + anion)

Distribution by Scientific Domains
Chemistry94%

Selected Abstracts

New Molecular Charge-Transfer Salts of TM-TTF and BMDT-TTF with Thiocyanate and Selenocyanate Complex Anions [TMTTF = Tetramethyltetrathiafulvalene; BMDT-TTF = Bis(methylenedithio)tetrathiafulvalene]

EUROPEAN JOURNAL OF INORGANIC CHEMISTRY, Issue 4 2003
Marta Mas-Torrent
Abstract Three new charge-transfer salts of tetrathiafulvalene (TTF)-based donors with thiocyanato- or selenocyanato-metal complex anions have been synthesised. The salts isolated were [BMDT-TTF]4[Cr(NCS)6] (1), [TM-TTF]4[Cr(NCS)6]·2CH3CN (2) and [TM-TTF]4[Cr(NCSe)6]·2CH3CN (3) [BMDT-TTF = bis(methylenedithio)tetrathiafulvalene and TM-TTF = tetramethyltetrathiafulvalene]. Single crystals of compound 1 crystallise in the monoclinic C2/c space group with a = 37.286(3), b = 10.0539(6), c = 21.069(2) Å, , = 124.348(4)°, V = 6520.9(9) Å3 and Z = 4. Compound 3 was also suitable for an X-ray diffraction study, however the anionic part, [Cr(NCSe)6], was highly disordered and the best solution gave a final R factor of 16.4%. A solution was found for the monoclinic space group C2/m with a = 13.787(3), b = 19.507(3), c = 14.735(5) Å, , = 102.90(3)°, V = 3862.9(17) Å3 and Z = 2. For compound 1 there are several S···S close atomic contacts between the donors and acceptors, but there is no discernible magnetic exchange between ions. Such an interaction was previously observed in related salts such as [TTF][Cr(NCS)4(phenanthroline)2] and [donor][M(NCS)4(isoquinoline)2] [M = Cr, Fe and donor = TTF, BEDT-TTF or TM-TTF (tetramethyltetrathiafulvalene)]. Compounds 1 to 3 are all paramagnetic semiconductors in which the magnetic susceptibility is dominated by the Cr-containing anions. The structure-function relationship, along with a comparison with related compounds, indicates that there is no long-range magnetic order because there are no ,-stacking interactions between donor and acceptor; these types of interactions are seen in all of the bulk magnets of this type in which the donor spin is magnetically coupled to the anion. (© Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2003) [source]

ChemInform Abstract: Suboxides with Complex Anions: The Suboxoindate Cs9InO4.

CHEMINFORM, Issue 21 2009
Constantin Hoch
Abstract ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a "Full Text" option. The original article is trackable via the "References" option. [source]

Bifunctional Materials Based on the Photochromic Cation [RuNO(NH3)5]3+ with Paramagnetic Metal Complex Anions.

CHEMINFORM, Issue 52 2006
Lyudmila A. Kushch
Abstract ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract, please click on HTML or PDF. [source]

Synthesis and Characterization of Transition-Metal Zintl Phases: Cs24Nb2In12As18 and Cs13Nb2In6As10 with Isolated Complex Anions.

CHEMINFORM, Issue 9 2004
Franck Gascoin
Abstract For Abstract see ChemInform Abstract in Full Text. [source]

Energetic Ionic Liquids based on Lanthanide Nitrate Complex Anions

CHEMISTRY - A EUROPEAN JOURNAL, Issue 35 2008
Guo-Hong Tao Dr.
Abstract Energetic ionic liquids based on anionic lanthanide nitrate complexes Cat+3[Ln(NO3)6]3,, where Cat+ is guanidinium, 4-aminotriazolium, 4-amino-1-methyltriazolium, 4-amino-1-ethyltriazolium, 4-amino-1-butyltriazolium, 1,5-diaminotetrazolium, and 1,5-diamino-4-methyltetrazolium, were prepared. The hexanitratolanthanate (-cerate) salts with the last two cations, which are the first CO-balanced energetic ionic liquids that are stable to hydrolysis and air, have impact sensitivities of about 27,J. These ionic liquids were obtained by an environmentally friendly, simple method using nitrate-containing precursors. All salts were fully characterized by IR and NMR spectroscopy, elemental analysis, and determination of thermal stability, phase behavior, density, and water content. According to theoretical calculations, these new compounds have potential as propellants. [source]

Mixed-Anion and Mixed-Cation Borohydride KZn(BH4)Cl2: Synthesis, Structure and Thermal Decomposition

EUROPEAN JOURNAL OF INORGANIC CHEMISTRY, Issue 11 2010
Dorthe B. Ravnsbæk
Abstract KZn(BH4)Cl2, synthesized for the first time, contains a heteroleptic complex anion [Zn(BH4)Cl2],, extending the structural diversity of metal borohydrides. In-situ synchrotron powder diffraction, NMR and Raman spectroscopy were used to characterize KZn(BH4)Cl2 and to evaluate the mechanism for its thermal decomposition. The title compound decomposes at a significantly lower temperature than KBH4 and may be used for inspiration for the design of novel hydrogen storage materials. Combining different ligands in modified metal borohydrides is proposed as a way to adjust stability with respect to hydrogen desorption. [source]

Kinetics and mechanism of oxidation of the drug mephenesin by bis(hydrogenperiodato)argentate(III) complex anion

INTERNATIONAL JOURNAL OF CHEMICAL KINETICS, Issue 8 2007
Shigang Shen
Mephenesin is being used as a central-acting skeletal muscle relaxant. Oxidation of mephenesin by bis(hydrogenperiodato)argentate(III) complex anion, [Ag(HIO6)2]5,, has been studied in aqueous alkaline medium. The major oxidation product of mephenesin has been identified as 3-(2-methylphenoxy)-2-ketone-1-propanol by mass spectrometry. An overall second-order kinetics has been observed with first order in [Ag(III)] and [mephenesin]. The effects of [OH,] and periodate concentration on the observed second-order rate constants k, have been analyzed, and accordingly an empirical expression has been deduced: k, = (ka + kb[OH,])K1/{f([OH,])[IO,4]tot + K1}, where [IO,4]tot denotes the total concentration of periodate, ka = (1.35 ± 0.14) × 10,2M,1s,1 and kb = 1.06 ± 0.01 M,2s,1 at 25.0°C, and ionic strength 0.30 M. Activation parameters associated with ka and kb have been calculated. A mechanism has been proposed to involve two pre-equilibria, leading to formation of a periodato-Ag(III)-mephenesin complex. In the subsequent rate-determining steps, this complex undergoes inner-sphere electron transfer from the coordinated drug to the metal center by two paths: one path is independent of OH, whereas the other is facilitated by a hydroxide ion. In the appendix, detailed discussion on the structure of the Ag(III) complex, reactive species, as well as pre-equilibrium regarding the oxidant is provided. © 2007 Wiley Periodicals, Inc. Int J Chem Kinet 39: 440,446, 2007 [source]

Tetrapotassium [,2 - N -carboxylato- d -penicillaminato(3,)-5:6,2S:S][,2 - d -penicillaminato(1,)-2:3,2S:S]tetrakis[,2 - d -penicillaminato(2,)]-1:2,3N,S:S;1:6,3N,S:S;3:4,3S:N,S;4:5,3N,S:S -2,3,5,6-tetragold(I)-1,4-dinickel(II) ethanol monosolvate decahydrate

ACTA CRYSTALLOGRAPHICA SECTION C, Issue 6 2010
Yuji Hashimoto
In the crystal structure of the title compound, K4[Au4Ni2(C6H8NO4S)(C5H9NO2S)4(C5H10NO2S)]·C2H6O·10H2O, (I), two planar [Ni(C5H9NO2S)2]2, units are spanned by [Au2(C5H10NO2S)]+ and [Au2(C6H8NO4S)], linkers through S atoms, forming an S:S -bridged AuI4NiII2 hexanuclear complex anion. One of six organic ligands in the complex anion is a carbamino derivative of d -penicillamine (3-mercaptovaline) and the others are deprotonated d -penicillamines. Each complex anion binds to nine K+ ions through six carboxylate and one carbamino groups to construct a three-dimensional structure. [source]

The sodium salt of a tris­(tridentate anion)­gadolinium(III) complex: penta­sodium bis­[chelidamato(3,)][chelidamato(2,)]­gadolinate(III) hexa­deca­hydrate

ACTA CRYSTALLOGRAPHICA SECTION C, Issue 4 2000
Annegret K. Hall
The sodium salt of a complex anion formed between gadolinium(III) and three variously deprotonated chelidamic acid (4-hydroxy­pyridine-2,6-di­carboxyl­ic acid) ligand moi­eties, assigned as Na5[Gd(C7H2NO5)2(C7H3NO5)]·16H2O, i.e. pentasodium (4-hydroxy­pyridine-2,6-di­carboxyl­ate)­bis(4-oxido­pyridine-2,6-di­carboxyl­ate)­gadolinium(III) hexadecahydrate, forms as colourless monoclinic crystals upon vapour diffusion of ethanol into its aqueous solution. The ligand moieties, assigned as two trianionic and one dianionic chelidamate species, are all tridentate in the complex anion of tricapped trigonal prismatic donor-atom geometry. The geometry of the ligands and that of the primary coordination sphere is very similar to that of the analogous anionic tris­(ligand),rare earth complexes of the pyridine-2,6-di­carboxyl­ate (dipicolinate) dianion. [source]

Thiocyanate overload and thyroid disease

BIOFACTORS, Issue 3-4 2003
Murat Faik Erdo
Abstract Thiocyanate [SCN,] is a complex anion which is a potent inhibitor of iodide transport. It is the detoxification product of cyanide and can easily be measured in body fluids. Consumption of naturally occurring goitrogens, certain environmental toxins and cigarette smoke can significantly increase SCN, concentrations to levels potentially capable of affecting the thyroid gland. Goiter endemics were reported to develop when the critical urinary iodine/ SCN, ratio decreases below 3 ,g iodine per mg SCN,. Iodine supplementation completely reverses the goitrogenic influence of SCN,. SCN, is also generated from cigarette smoking as a detoxifying product of cyanide. During the past two decades many reports dealt with the possible effects of cigarette smoking on thyroid hormone synthesis, thyroid gland size and thyroid autoimmunity including infiltrative ophtalmopathy of Graves' disease. In this mini-review, issues regarding thiocyanate overload and thyroid disease will be summarized. [source]

Synthesis, Crystal Structure of Cis -dioxo-catecholatotungsten(VI) Complex and Its NMR Studies on the Interaction with ATP

CHINESE JOURNAL OF CHEMISTRY, Issue 6 2003
Lu Xiao-Ming
Abstract Cis -dioxo-catecholatotungsten(VI) complex anion [W(VI)O2 -(OC6H2O)]2- was obtained with discrete protonated ethylene-diamine (NH2CH2CH2NH3)+ cations by the reaction of tetra-butyl ammonium decatungstate with catechol in the mixed solvent of CH3OH, CH3CN and ethylenediamine, and compared with its molybdenum analogue [Mo(v)O2(OC6H4O)2]3- by crystal structure, UV, EPR. The results of the UV and EPR spectra show that tungsten is less redox active than molybdenum since the molybdenum is reduced from Mo(VI) to Mo(V) but tungsten stays in the original highest oxidized state Mo (VI) when they are crystallized from the solution above. It is worthy to note that [W(VI)O2(OC6H4O2)]2- shows the same coordination structure as its molybdenum analogue in which the metal center exhibits distorted octahedral coordination geometry with two cis -dioxocatecholate ligands and might have the related coordination structure feature with the cofactor of flavoenzyme because [Mo(v)O2(OC6H4O)2]3- presented essentially the same EPR spectra as flavoenzyme. The NMR studies on the interaction of the title complex with ATP reveal that the reduction of W(VI) to W(V) occurs when the title complex is dissolved in D2O and the W (V) is oxidized again when ATP solution is mixed with original solution and the hydrolysis of the catechola-to ligand take places at mean time being monitored by 1H NMR and 13C NMR spectra. [source]

Advances in the Study of Ion Transfer at Liquid Membranes with Two Polarized Interfaces by Square Wave Voltammetry

ELECTROANALYSIS, Issue 14 2010
A. Molina
Abstract A general analytical expression has been deduced for the I/E response of the square wave voltammetry corresponding to ion transfer processes in systems with two liquid/liquid polarized interfaces. This expression has been evaluated through the experimental study of a series of quaternary ammonium cations and metal chloro complex anions. We have found that systems with two liquid/liquid polarizable interfaces present the striking advantage that the difference between peak potentials of square wave voltammograms of cations and anions with similar standard ion transfer potential is much greater than in systems with a single polarizable one. [source]

New Molecular Charge-Transfer Salts of TM-TTF and BMDT-TTF with Thiocyanate and Selenocyanate Complex Anions [TMTTF = Tetramethyltetrathiafulvalene; BMDT-TTF = Bis(methylenedithio)tetrathiafulvalene]

EUROPEAN JOURNAL OF INORGANIC CHEMISTRY, Issue 4 2003
Marta Mas-Torrent
Abstract Three new charge-transfer salts of tetrathiafulvalene (TTF)-based donors with thiocyanato- or selenocyanato-metal complex anions have been synthesised. The salts isolated were [BMDT-TTF]4[Cr(NCS)6] (1), [TM-TTF]4[Cr(NCS)6]·2CH3CN (2) and [TM-TTF]4[Cr(NCSe)6]·2CH3CN (3) [BMDT-TTF = bis(methylenedithio)tetrathiafulvalene and TM-TTF = tetramethyltetrathiafulvalene]. Single crystals of compound 1 crystallise in the monoclinic C2/c space group with a = 37.286(3), b = 10.0539(6), c = 21.069(2) Å, , = 124.348(4)°, V = 6520.9(9) Å3 and Z = 4. Compound 3 was also suitable for an X-ray diffraction study, however the anionic part, [Cr(NCSe)6], was highly disordered and the best solution gave a final R factor of 16.4%. A solution was found for the monoclinic space group C2/m with a = 13.787(3), b = 19.507(3), c = 14.735(5) Å, , = 102.90(3)°, V = 3862.9(17) Å3 and Z = 2. For compound 1 there are several S···S close atomic contacts between the donors and acceptors, but there is no discernible magnetic exchange between ions. Such an interaction was previously observed in related salts such as [TTF][Cr(NCS)4(phenanthroline)2] and [donor][M(NCS)4(isoquinoline)2] [M = Cr, Fe and donor = TTF, BEDT-TTF or TM-TTF (tetramethyltetrathiafulvalene)]. Compounds 1 to 3 are all paramagnetic semiconductors in which the magnetic susceptibility is dominated by the Cr-containing anions. The structure-function relationship, along with a comparison with related compounds, indicates that there is no long-range magnetic order because there are no ,-stacking interactions between donor and acceptor; these types of interactions are seen in all of the bulk magnets of this type in which the donor spin is magnetically coupled to the anion. (© Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2003) [source]

Mass spectrometric behaviour of ion-pair precipitates of some complex anions with ethoxylate complex of barium

JOURNAL OF MASS SPECTROMETRY (INCORP BIOLOGICAL MASS SPECTROMETRY), Issue 2 2001
Andrzej Szyma
[source]

Octakis(dimethylammonium) hexa-,2 -chlorido-hexachloridotrinickelate(II) dichloride: a linear trinickel complex with asymmetric bridging

ACTA CRYSTALLOGRAPHICA SECTION C, Issue 10 2009
Allison Gerdes
The title compound, (C2H8N)8[Ni3Cl12]Cl2, crystallizes as linear [Ni3Cl12]6, complex anions with inversion symmetry, separated from one another by dimethylammonium cations and noncoordinated chloride ions. The gross structural arrangement of the trinickel complex is as a segment of face-sharing NiCl6 octahedra similar to the (NiCl3)n chains of CsNiCl3 -type compounds. On closer inspection, the regular coordination geometry of the complex consists of octahedral NiCl6 in the center linked by two symmetrically bridging chloride ions to square-pyramidal NiCl5 on each end. A long semicoordinate bond is formed by each of the terminal NiII cations, to give a 5+1 coordination geometry and form an asymmetric bridge to the central NiII cation. The dimethylammonium cations surround the complex with an extensive hydrogen-bonding network, linking the complex to the noncoordinated chloride ions. Asymmetric bridging in the complex arises from short hydrogen bonds from the same dimethylammonium cation to the apical and asymmetric bridging chloride ions, causing the complex to scissor outward. [source]

Bis(1,3,4-trimethylpyridinium) tetrachloridocuprate(II) and bis(1,3,4-trimethylpyridinium) tetrabromidocuprate(II): an examination of the A2CuX4Fdd2 structure type

ACTA CRYSTALLOGRAPHICA SECTION C, Issue 8 2009
Marcus R. Bond
The title bis(1,3,4-trimethylpyridinium) tetrahalidocuprate(II) structures, (C8H12N)2[CuCl4], (I), and (C8H12N)2[CuBr4], (II), respectively, consist of flattened [CuX4]2, tetrahedral complex anions and planar 1,3,4-trimethylpyridinium cations. Chloride compound (I) is a rare example of an A2CuCl4 structure with an elongated unit cell in the polar space group Fdd2. The [CuCl4]2, anions have twofold rotational symmetry and are arranged in distorted hexagonal close-packed (hcp) layers, which are interleaved with layers of cations, each in a four-layer repeat sequence, to generate the elongated axis. The organic cations stack along [101] or [10] in alternating layers. The methyl groups meta on the cation ring and the larger of the trans Cl,Cu,Cl angles both face the same direction along the polar axis and are the most prominent features determining the polarity of the structure. Bromide compound (II) crystallizes in a centrosymmetric structure with a similar layer structure but with only a two-layer repeat sequence. Here, symmetry-inequivalent cations are segregated into alternating layers with cations, forming hcp layers of inversion-related cation pairs in one layer and parallel stacks of cations in the other. The change in space group when the larger Br, ion is present suggests that the 1,3,4-trimethylpyridinium ion has a minimal size to allow the Fdd2 A2CuX4 structure type. [source]