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Coordination Compound (coordination + compound)
Selected AbstractsStudies in Solution and the Solid State of Coordination Compounds Derived from LiBH4, NaBH4, and Bidentate Aromatic AminesEUROPEAN JOURNAL OF INORGANIC CHEMISTRY, Issue 13 2010Milagros Aguilar-Martínez Abstract The mixture of 2,2,-bipyridylamine, 2,2,-bipyridine, 1,10-phenanthroline, 1,2-phenylendiamine, and 1,4-phenylendiamine each with LiBH4 and NaBH4 in a 1:1 molar ratio in THF yields seven new complexes of the type MBH4·L-THF and one complex of the type MBH4·L. These compounds were characterized by IR and NMR spectroscopy and X-ray single-crystal structure determinations. In the solid state, the [BH4], group is bidentate, as deduced from the stretching patterns observed in IR spectra and confirmed by X-ray single-crystal structure analysis. NMR spectroscopy showed that all amines act as bidentate ligands and are symmetrically coordinated to the metal cation. Complexes LiBH4 -2,2,-bipyridine-THF (1), NaBH4 -2,2,-bipyridine-THF (2), LiBH4 -1,10-phenanthroline-THF (3), and NaBH4 -1,10-phenanthroline-THF (4) have a discrete molecular structure, whereas the complexes LiBH4 -1,2-phenylendiamine-THF (5), NaBH4 -1,2-phenylendiamine-THF (6), LiBH4 -2,2,-dipyridilamine (7), and LiBH4 -1,4-phenylendiamine-THF (8) have polymeric structures in the solid state. N -borane-dipyridylamine adduct 9 was isolated from an aged solution of 7. IR spectroscopy of the new complexes showed that the structures of complexes 1, 3, 4, and 6 are maintained in the solid state and in solution. A rotational barrier for the [BH4], group of less than 38 KJ,mol,1 was estimated for some of the new complexes. [source] [(Pyridylcarbonyl)pyridyl]triazolopyridines, Useful Ligands for the Construction of Polynuclear Coordination Compounds , Synthesis, Crystal Structure and Magnetic Properties of a Novel Tetranuclear Copper(II) Cubane,EUROPEAN JOURNAL OF INORGANIC CHEMISTRY, Issue 29 2007Belén Abarca Abstract A new tetranuclear cubane Cu4O4 complex has been synthesised from assembly of CuII ions and the polydentate ligand (pyridin-2-yl){6-([1,2,3]triazolo[1,5- a]pyridin-3-yl)pyridin-2-yl}methanone. Crystallographic analysis indicates that the Cu4O4 unit has an S4 symmetry. The magnetic properties have been analysed using the H = ,2,i,jJijSiSj spin Hamiltonian. Two distinct coupling constants, 2J1,3 = ,37.4 cm,1 and 2J1,2 = ,2.6 cm,1, obtained from the fitting of the experimental data have been rationalised on the basis of a density functional study of magnetostructural correlations in cubane complexes containing the Cu4O4 core. (© Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2007) [source] Asymmetric Synthesis of Coordination Compounds: Back to the Roots.HELVETICA CHIMICA ACTA, Issue 10 2005Diastereoselective Synthesis of Simple Platinum(IV) Complexes No abstract is available for this article. [source] Kazuo Nakamoto Infrared and Raman Spectra of Inorganic and Coordination Compounds, Part B, Applications in Coordination, Organometallic, and Bioinorganic Chemistry, 6th edn Wiley, 2009, 424 pp. (hardback) ISBN 978-0-471-74493-1APPLIED ORGANOMETALLIC CHEMISTRY, Issue 6 2010Alan Brisdon No abstract is available for this article. [source] ChemInform Abstract: Octahedral Coordination Compounds of the Ni, Pd, Pt TriadCHEMINFORM, Issue 18 2008Marius Kirchmann 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] From Single-Molecule Precursors to Coupled Ag2S/TiO2 NanocompositesEUROPEAN JOURNAL OF INORGANIC CHEMISTRY, Issue 28 2008Márcia C. Neves Abstract A single-source approach using mild temperatures was applied to prepare morphological well-defined and coupled TiO2/metal,sulfide nanocomposites. Metal N -alkyldithiocarbamates were used as the precursors to the metal,sulfide nanophases and, in particular, Ag2S nanostructures were investigated in more detail. These were observed as nano-islands at the surface of TiO2 (anatase) particles, which were used as substrates. To explain the formation of these nanocomposite particulates, a tentative mechanism has been proposed which involves the controlled release of sulfide ions from an intermediate coordination compound. Because the growth of the metal sulfide can be controlled at the surface of a photoactive substrate, we anticipate the potential of this synthetic method to chemical design reasonable amounts of semiconductor-sensitized TiO2, such as Ag2S/TiO2 nanocomposites. (© Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2008) [source] Coordination Polymers: Organization of Coordination Polymers on Surfaces by Direct Sublimation (Adv. Mater.ADVANCED MATERIALS, Issue 20 200920/2009) Sublimation and surface reassembly of coordination polymers is introduced by Felix Zamora and co-workers on page 2025. This striking phenomenon is achieved due to the reversibility of the coordination bonds, which allows the polymers to be sublimated in form of small oligomers and reassembled on the surface. Temperature-controlled transition to a 1D organization reflecting the 1D bulk structure of the coordination compound is observed by atomic force microscopy. [source] Structure determination of the [Fe(teec)6](BF4)2 metal complex from laboratory and synchrotron X-ray powder diffraction data with grid-search techniquesACTA CRYSTALLOGRAPHICA SECTION B, Issue 4 2001Eva Dova The structure of the coordination compound [Fe(teec)6](BF4)2, hexa[1-(2-chloroethyl)tetrazole]iron(II) di(borotetrafluoride), has been determined using the grid-search techniques of the program suite MRIA. A Guinier-camera data set was used to determine the unit cell, the space group and to position the initial model. A high-resolution synchrotron powder data set was used to position a more detailed model using torsion-angle variation and to refine the structure leading to Rp = 0.0689, Rw = 0.0805 and GoF = 1.38. The crystal structure at room temperature shows the existence of two symmetry-equivalent iron(II) ions in the high-spin state. [source] An unusual polycatenating network self-assembled by the 2D , 2D parallel , 3D parallel interpenetration of coordinative and hydrogen-bonded (6,3) motifsACTA CRYSTALLOGRAPHICA SECTION C, Issue 4 2010Suna Wang In the title coordination compound, catena -poly[[[bis[diaquacadmium(II)]-,2 - trans -1,2-bis(4-pyridyl)ethene]bis{,2 -2,2,-[(5-carboxymethoxy- m -phenylene)dioxy]diacetato}] trans -1,2-bis(4-pyridyl)ethene solvate dihydrate], {[Cd2(C12H10O9)2(C12H10N2)(H2O)4]·C12H10N2·2H2O}n, (I), each CdII centre adopts a pentagonal,bipyramidal coordination geometry. The incompletely deprotonated 2,2,-[(5-carboxymethoxy- m -phenylene)dioxy]diacetate (TCMB) ligands and trans -1,2-bis(4-pyridyl)ethene (bpe) ligands both act as bidentate bridges, linking the CdII centres into one-dimensional ladders, which are connected into an undulating two-dimensional (6,3) layer through O,H...N hydrogen bonds between the carboxylate groups of the TCMB ligands and the N atoms of the uncoordinated bpe ligands. Each undulating layer polycatenates two other identical layers, exhibiting the unusual combination of both 2D , 2D parallel and 2D , 3D parallel interpenetration (2D and 3D are two- and three-dimensional, respectively). [source] Poly[[aqua(4,4,-diazenediyldibenzoato-,4O,O,:O,,,O,,,)cadmium(II)]: a twofold interpenetrated three-dimensional coordination polymer of PtS topologyACTA CRYSTALLOGRAPHICA SECTION C, Issue 10 2009Ru-Guo Wang In the title coordination compound, [Cd(C14H8N2O4)(H2O)]n, the CdII cation and the coordinated water molecule lie on a twofold axis, whereas the ligand lies on an inversion center. The CdII center is five-coordinated in a distorted square-pyramidal geometry by four carboxylate O atoms from four different 4,4,-diazenediyldibenzoate (ddb) anions and one water O atom. The three-dimensional frameworks thus formed by the bridging ddb anions interpenetrate to generate a three-dimensional PtS-type network. Additionally, the coordination water molecule and the carboxylate O atom form a hydrogen-bonding interaction, stabilizing the three-dimensional framework structure. [source] A novel parallel interpenetrating two-dimensional (4,4) network: poly[[,2 -1,4-bis(imidazol-1-ylmethyl)benzene](,2 -naphthalene-1,4-dicarboxylato)zinc(II)]ACTA CRYSTALLOGRAPHICA SECTION C, Issue 9 2009Ya-Ping Li In the title coordination compound, [Zn(C12H6O4)(C14H14N4)]n, the two ZnII centers exhibit different coordination environments. One ZnII center is four-coordinated in a distorted tetrahedral environment surrounded by two carboxylate O atoms from two different naphthalene-1,4-dicarboxylate (1,4-ndc) anions and two N atoms from two distinct 1,4-bis(imidazol-1-ylmethyl)benzene (1,4-bix) ligands. The coordination of the second ZnII center comprises two N atoms from two different 1,4-bix ligands and three carboxylate O atoms from two different 1,4-ndc ligands in a highly distorted square-pyramidal environment. The 1,4-bix ligand and the 1,4-ndc anion link adjacent ZnII centers into a two-dimensional four-connected (4,4) network. The two (4,4) networks are interpenetrated in a parallel mode. [source] A bis(amine,carboxylate) copper(II) coordination compound forms a two-dimensional metal,organic framework when crystallized from water and methanolACTA CRYSTALLOGRAPHICA SECTION C, Issue 9 2009Orde Q. Munro When {2,2,-[(2-methyl-2-nitropropane-1,3-diyl)diimino]diacetato}copper(II), [Cu(C8H13N3O6)], (I), was crystallized from a binary mixture of methanol and water, a monoclinic two-dimensional water- and methanol-solvated metal,organic framework (MOF) structure, distinctly different from the known orthorhombic one-dimensional coordination polymer of (I), was isolated, namely catena -poly[[copper(II)-,3 -2,2,-[(2-methyl-2-nitropropane-1,3-diyl)diimino]diacetato] methanol 0.45-solvate 0.55-hydrate], {[Cu(C8H13N3O6)]·0.45CH3OH·0.55H2O}n, (II). The monoclinic structure of (II) comprises centrosymmetric dimers stabilized by a dative covalent Cu2O2 core and intramolecular N,H...O hydrogen bonds. Each dimer is linked to four neighbouring dimers via symmetry-related (opposing) pairs of bridging carboxylate O atoms to generate a `diamondoid' net or two-dimensional coordination network. Tight voids of 166,Ĺ3 are located between these two-dimensional MOF sheets and contain a mixture of water and methanol with fractional occupancies of 0.55 and 0.45, respectively. The two-dimensional MOF sheets have nanometre-scale spacings (11.2,Ĺ) in the crystal structure. Hydrogen-bonding between the methanol/water hydroxy groups and a Cu-bound bridging carboxylate O atom apparently negates thermal desolvation of the structure below 358,K in an uncrushed crystal of (II). [source] Poly[diaqua[,-1,4-bis(imidazol-1-ylmethyl)benzene-,2N3:N3,](,- trans -cyclohexane-1,4-carboxylato-,2O1:O4)manganese(II)]: a three-dimensional hydrogen-bonding ,-polonium netACTA CRYSTALLOGRAPHICA SECTION C, Issue 8 2009Qing-Wei Wang In the title coordination compound, [Mn(C8H10O4)(C14H14N4)(H2O)2]n, each MnII centre occupies an inversion centre. The 1,4-bis(imidazol-1-ylmethyl)benzene (1,4-bix) ligand and the trans -cyclohexane-1,4-dicarboxylate dianion (chdc) both function in bridging modes, linking adjacent MnII centres into a two-dimensional four-connected (4,4) network. These two-dimensional layers are stacked in a parallel mode. Hydrogen bonds between water molecules and carboxylate O atoms link neighbouring (4,4) networks, yielding a three-dimensional ,-polonium net. [source] Poly[[[,-1,1,-(butane-1,4-diyl)diimidazole-,2N:N,](,-cyclohexane-1,4-dicarboxylato-,4O1,O1,:O4,O4,)cadmium(II)] hemihydrate]: a parallel interpenetrating two-dimensional (4,4) networkACTA CRYSTALLOGRAPHICA SECTION C, Issue 2 2009Shi Zhou In the title coordination compound, {[Cd(C8H10O4)(C10H14N4)]·0.5H2O}n, the 1,1,-(butane-1,4-diyl)diimidazole ligand and the cyclohexane-1,4-dicarboxylate dianion both function in a bridging mode to link adjacent cadmium(II) centers into a two-dimensional four-connected (4,4) network. The networks are parallel to the (001) plane. Two (4,4) networks are interpenetrated in an unusual parallel mode. The compound is the first two-dimensional parallel interpenetrating (4,4) network structure based on a flexible dicarboxylate and a long bidentate N -donor ligand. The interpenetrating nets are further consolidated by water,carboxylate O,H...O hydrogen bonds. [source] KP1019, A New Redox-Active Anticancer Agent , Preclinical Development and Results of a Clinical Phase I Study in Tumor PatientsCHEMISTRY & BIODIVERSITY, Issue 10 2008Christian Abstract The promising drug candidate indazolium trans -[tetrachlorobis(1H -indazole)ruthenate(III)] (KP1019) is the second Ru-based anticancer agent to enter clinical trials. In this review, which is an update of a paper from 2006 (Hartinger et,al., J. Inorg. Biochem.2006, 100, 891,904), the experimental evidence for the proposed mode of action of this coordination compound is discussed, including transport into the cell via the transferrin cycle and activation by reduction. The results of the early clinical development of KP1019 are summarized in which five out of six evaluated patients experienced disease stabilization with no severe side effects. [source] Theoretical and experimental luminescence quantum yields of coordination compounds of trivalent europiumINTERNATIONAL JOURNAL OF QUANTUM CHEMISTRY, Issue 5 2005Wagner M. Faustino Abstract An appraisal of a semiempirical methodology recently introduced by us for the theoretical calculation of luminescence quantum yields is presented. Six coordination compounds of Eu3+ were considered, possessing either benzoylacetonate or benzoyltrifluoroacetonate, together with either water, 2,2,-bipyridine, or 1,10-phenanthroline as ligands. Their geometries were calculated using the SMLC/AM1 method. The ligand,Eu3+ energy transfer rates were calculated in terms of a model of intramolecular energy transfer processes in lanthanide coordination compounds developed earlier by our group. The luminescence quantum yields of the complexes were calculated by solving numerically a system of rate equations for each compound, and by comparing them with the quantum yields determined spectroscopically. Finally, we show that the theoretical quantum yields correlate linearly with the experimental yields, within their error bars. Such linear correlation indicates that the theoretical approach can be useful for the a priori design of highly luminescent lanthanide coordination compounds. © 2005 Wiley Periodicals, Inc. Int J Quantum Chem, 2005 [source] Formation of Nanostructures in Multi Component Systems Based on Organic Polymer and Coordination Metal CompoundMACROMOLECULAR SYMPOSIA, Issue 1 2006Nataly Kozak Abstract Structuring of polyurethane (PU) networks is analyzed under influence of transition metal coordination compounds: mono-ionic ,-diketonates and polyheteronuclear metal-organic complexes. Formed in situ nanostructures both organic and inorganic were found in organic polymer modified with coordination metal compound. Influence of coordination junction point spatial symmetry and content of metal ion in modifier on structure and dielectric characteristics of modified PUs is analyzed using X-ray, EPR, SEM and transmission optical microscopy, DRS and DSC methods. [source] 15N NMR coordination shifts in Pd(II), Pt(II), Au(III), Co(III), Rh(III), Ir(III), Pd(IV), and Pt(IV) complexes with pyridine, 2,2,-bipyridine, 1,10-phenanthroline, quinoline, isoquinoline, 2,2,-biquinoline, 2,2,:6,, 2,-terpyridine and their alkyl or aryl derivativesMAGNETIC RESONANCE IN CHEMISTRY, Issue S1 2008Leszek Pazderski Abstract The 15N NMR data for 105 complexes of Pd(II), Pt(II), Au(III), Co(III), Rh(III), Ir(III), Pd(IV), and Pt(IV) complexes with simple azines such as pyridine, 2,2,-bipyridine, 1,10-phenanthroline, quinoline, isoquinoline, 2,2,-biquinoline, 2,2':6', 2"-terpyridine and their alkyl or aryl derivatives have been reviewed. The 15N NMR coordination shifts, i.e. the differences between the 15N chemical shifts of the same nitrogen in the molecules of the complex and the ligand (,15Ncoord = ,15Ncompl , ,15Nlig), have been related to some structural features of the reviewed coordination compounds, like the type of the central ion and the character of auxiliary ligands (mainly in trans position). These ,15Ncoord parameters are negative, their absolute magnitudes (ca 30,150 ppm) generally increasing in the metal order Au(III) < Pd(II) < Pt(II) and Rh(III) < Co(III) < Pt(IV) < Ir(III), as well as with the enhanced trans influence of the other donor atoms (H, C , Cl < N). Copyright © 2008 John Wiley & Sons, Ltd. [source] Change in the magnetic properties of [FeII(phen)3](PF6)2 in the solid state by combining grinding and annealingPHYSICA STATUS SOLIDI (A) APPLICATIONS AND MATERIALS SCIENCE, Issue 4 2004T. Ohshita Abstract By grinding crystalline [FeII(phen)3](PF6)2, the effective magnetic moment, or ,MT, increased with simultaneous amorphization. Subsequent annealing further increased ,MT, despite the restoration of the crystallinity. This was explained by the recovery of the counterion, PF6,, from its strained state in the intact crystal to a less strained state towards higher spherical symmetry. The effects of annealing preceded by grinding suggest a novel method to control the magnetic states of coordination compounds without regard to their crystalline states. (© 2004 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim) [source] Electron-density studies of molecular magnetic materialsACTA CRYSTALLOGRAPHICA SECTION A, Issue 5 2004Sébastien Pillet For more than forty years, the experimental determination and analysis of electron densities have played a fundamental role in advances in the chemical bond concept. The present paper illustrates the application of this approach to the field of molecular magnetism with examples that recently appeared in the literature. Particular attention is attached to several classes of materials, purely organic free radicals, coordination compounds and organometallic complexes, which exhibit specific magnetic behaviors. It is shown to what extent the electron-density analysis can shed light on bonding aspects that are closely related to magnetic couplings. Relations between spin delocalization, spin polarization, superexchange and the characteristics of the electron density are described. The use of the topological theory of `atoms in molecules' allows the possible magnetic interaction pathways to be located and defined, especially through weak intermolecular contacts. The complementarity with polarized neutron diffraction and spin-density modeling techniques is particularly evident from the chosen examples. [source] Synthesis, Crystal Structure, Thermal Decomposition and Sensitivity Properties of [Zn(AZT)4(H2O)2](PA)2·4H2O and [Zn(AZT)2(H2O)4](HTNR)2·4H2OCHINESE JOURNAL OF CHEMISTRY, Issue 11 2008Yan CUI Two new coordination compounds [Zn(AZT)4(H2O)2](PA)2· 4H2O and [Zn(AZT)2(H2O)4]- (HTNR)2·4H2O have been prepared by using AZT (3-azido- 1,2,4-triazole) as ligands, PA, (picrate) or HTNR, (anion formed by the deprotonation of one of the two hydroxyl-groups of 2,4,6-trinitroresorcinol) as outer anions. The central zinc(II) ion is coordinated by four N atoms of four AZT molecules and two O atoms of two H2O molecules in [Zn(AZT)4(H2O)2](PA)2·4H2O. In [Zn(AZT)2(H2O)4](HTNR)2· 4H2O, six coordination-atoms come from two N atoms of two AZT molecules and four O atoms of four H2O molecules. [source] Contributions to the theory and practice of the chromatographic separation of enantiomers,CHIRALITY, Issue S1 2005Volker Schurig Abstract The theory and practice of enantioselective capillary chromatography employing metal coordination compounds and modified cyclodextrins as chiral stationary phases are treated. A unified approach involving all contemporary chromatographic methods and a single enantioselective column is described. Reliable thermodynamic data of enantioselectivity are derived by the retention-increment method. The existence of an isoenantioselective temperature is demonstrated. Kinetic enantiomerization studies are presented. The preparative-scale separation of enantiomers by gas chromatography with enantioselective packed columns is achieved. Unusual phenomena and future aspects of enantioselective chromatography are discussed. Chirality 17:S205,S226, 2005. © 2005 Wiley-Liss, Inc. [source] | |||||||||||||||||||||||||