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Cluster Anions (cluster + anion)
Selected AbstractsChemInform Abstract: Synthesis and Structure of the Novel Pentaselenidohexaarsenate(I,II) Cluster Anion [As6Se5]2- .CHEMINFORM, Issue 24 2008Anna Kromm 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] ChemInform Abstract: Complementary Active Sites Cause Size-Selective Reactivity of Aluminum Cluster Anions with Water.CHEMINFORM, Issue 15 2009Patrick J. Roach 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] Doping Golden Buckyballs: Cu@Au16 - and Cu@Au17 - Cluster Anions.CHEMINFORM, Issue 26 2007Lei-Ming Wang 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] Infrared Spectroscopy of Water Cluster Anions, (H2O)n=3-24 - in the HOH Bending Region: Persistence of the Double H-Bond Acceptor (AA) Water Molecule in the Excess Electron Binding Site of the Class I Isomers.CHEMINFORM, Issue 35 2006Joseph R. Roscioli 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] Fourier transform Raman spectroscopic study of pressure-induced ligand bond activation in a molybdenum,sulfur cluster,JOURNAL OF RAMAN SPECTROSCOPY, Issue 3 2002Ian S. Butler Fourier transform Raman spectra of the prototype, triangular, transition metal,sulfur cluster anion [Mo3(S2)6S]2, were recorded at pressures up to 60 kbar with the aid of a diamond-anvil cell (DAC). The pressure dependences (,,/,p) of the Raman bands indicate a structural change at around 10,15 kbar. The SS stretching mode for the bridging disulfide ligands exhibits a slightly negative ,,/,p value (,0.08), suggesting that SS bonds are weakened, i.e. activated, at high pressures. This pressure-induced activity parallels the observed nucleophilic substitution reactivity of the S2 groups in this molybdenum cluster anion. In view of this, a preliminary investigation of the reaction between [Mo3(S2)6S]2, and CN, was undertaken in the solid state in the DAC under high pressure. Copyright © 2002 John Wiley & Sons, Ltd. [source] Tetrakis(tetramethylammonium) dodeca-,-chloro-hexachloro- octahedro -hexatantalate chlorideACTA CRYSTALLOGRAPHICA SECTION C, Issue 1 2004Marija Vojnovi The title compound, (C4H12N)4[Ta6Cl18]Cl, crystallizes in the cubic space group . The crystal structure contains two different types of coordination polyhedra, i.e. four tetrahedral [(CH3)4N]+ cations and one octahedral [(Ta6Cl12)Cl6]3, cluster anion, and one Cl, ion. The presence of three different kinds of Cl atoms [bridging (,2), terminal and counter-anion] in one molecule makes this substance unique in the chemistry of hexanuclear halide clusters of niobium and tantalum. The Ta6 octahedron has an ideal Oh symmetry, with a Ta,Ta interatomic distance of 2.9215,(7),Å. [source] (C6H14N2)2[VO(HPO4)5B2O]·H2O·H3PO4, a novel borophosphate cluster containing a single vanadium centre and linked by hydrogen bonds into a three-dimensional frameworkACTA CRYSTALLOGRAPHICA SECTION C, Issue 3 2003Emma Wikstad The title novel vanadium borophosphate compound, bis(1,4-diazonia[2.2.2]octane) ,3 -oxo-oxopenta-,-phosphato-diboronvanadium monohydrate phosphoric acid solvate, containing the cluster anion [VO(PO3OH)5B2O]4,, has been synthesized under mild hydrothermal conditions. Extensive O,H,O and N,H,O hydrogen bonding is observed between the molecular units. [source] The arsenic clusters Asn (n = 1,5) and their anions: Structures, thermochemistry, and electron affinitiesJOURNAL OF COMPUTATIONAL CHEMISTRY, Issue 7 2004Yi Zhao Abstract The molecular structures, electron affinities, and dissociation energies of the Asn/As (n = 1,5) species have been examined using six density functional theory (DFT) methods. The basis set used in this work is of double-, plus polarization quality with additional diffuse s - and p -type functions, denoted DZP++. These methods have been carefully calibrated (Chem Rev 2002, 102, 231) for the prediction of electron affinities. The geometries are fully optimized with each DFT method independently. Three different types of the neutral-anion energy separations reported in this work are the adiabatic electron affinity (EAad), the vertical electron affinity (EAvert), and the vertical detachment energy (VDE). The first dissociation energies De(Asn,1 -As) for the neutral Asn species, as well as those De(As -As) and De (Asn,1 -As,) for the anionic As species, have also been reported. The most reliable adiabatic electron affinities, obtained at the DZP++ BLYP level of theory, are 0.90 (As), 0.74 (As2), 1.30 (As3), 0.49 (As4), and 3.03 eV (As5), respectively. These EAad values for As, As2, and As4 are in good agreement with experiment (average absolute error 0.09 eV), but that for As3 is a bit smaller than the experimental value (1.45 ± 0.03 eV). The first dissociation energies for the neutral arsenic clusters predicted by the B3LYP method are 3.93 eV (As2), 2.04 eV (As3), 3.88 eV (As4), and 1.49 eV (As5). Compared with the available experimental dissociation energies for the neutral clusters, the theoretical predictions are excellent. Two dissociation limits are possible for the arsenic cluster anions. The atomic arsenic results are 3.91 eV (As , As, + As), 2.46 eV (As , As + As), 3.14 eV (As , As + As), and 4.01 eV (As , As + As). For dissociation to neutral arsenic clusters, the predicted dissociation energies are 2.43 eV (As , As2 + As,), 3.53 eV (As , As3 + As,), and 3.67 eV (As , As4 + As,). For the vibrational frequencies of the Asn series, the BP86 and B3LYP methods produce good results compared with the limited experiments, so the other predictions with these methods should be reliable. © 2004 Wiley Periodicals, Inc. J Comput Chem 25: 907,920, 2004 [source] Structure of new porous compounds after annealing in vacuumJOURNAL OF SYNCHROTRON RADIATION, Issue 2 2001S. B. Erenburg Dehydration process in recently synthesized porous inorganic salts formed by large cluster anions [Re6X8(CN)6]4- (X= S, Se), transition metal cations and water molecules has been investigated. Desolvation process of the complex Co(DMF)6[Mo6Br8(NCS)6], where DMF - dimethylformamide, has been studied. CoK, MoK and ReL3 XAFS measurements of these new complicated compounds before and after annealing in vacuum at temperature up to 250°C were performed. Changes of electronic and spatial structure of these compounds under the heating process have been established and adequate structural models of the amorphous compounds obtained are suggested and discussed. [source] Formation, growth mechanism and packing sequences of binary alloy cluster anions from laser ablation of mixtures of lead and transition metalsRAPID COMMUNICATIONS IN MASS SPECTROMETRY, Issue 6 2003Xia Zhang By using laser ablation of the mixtures of a transition metal (M: Ti, Cr, Mn, Fe, Co, Ni, Cu, Zn, Pd, Ag) plus lead, M/Pb binary cluster anions were observed except for Zn, and the number of transition metal atoms contained in the binary clusters is at most 4. This behavior is different from that reported previously for M/Ge binary clusters. The experiments indicate that it is also very difficult to form Al/Pb clusters. The distribution patterns of M/Pb binary alloy cluster anions are remarkably similar to those of pure Pb clusters, consistent with a formation mechanism in which transition metal atoms are sequentially attached to [Mx,1Pby], clusters and thus form [MxPby], clusters by a simple condensation process. As the number of transition metal atoms increases, the intensities of binary clusters gradually decrease. It is proposed that [MPb4], and [MPb5], cluster anions might be the unit building blocks of M/Pb binary cluster anions, and the layer packing sequences for magic clusters are predicted on this basis. The [MxPby], binary clusters containing 13 atoms (x,+,y,=,13; x,,,0) are proposed to have an icosahedral structure. Copyright © 2003 John Wiley & Sons, Ltd. [source] Formation of binary alloy cluster ions from group-14 elements and cobalt and comparison with solid-state alloysRAPID COMMUNICATIONS IN MASS SPECTROMETRY, Issue 24 2001Xia Zhang By using laser ablation on mixtures of transition metal cobalt and group-14 elements, binary alloy cluster anions were produced while no binary alloy cluster cations were detected, and the homocluster cations of group-14 elements appeared at very low abundance. The differences between clustering abilities of germanium, tin and lead with cobalt are described, and the chemical bonds in the binary alloy cluster anions appear to indicate a transition from covalent to metal bonds. The cluster anion [CoPb10], appears in very high abundance (magic number), and an endohedral structure is proposed for this cluster. The cluster anion [CoPb12],, also representing a magic number, probably has an icosahedral structure. Compared with solid-state Co/Ge binary alloys, the compositions of most binary alloy cluster anions are germanium-rich, in which the covalent bonds are predominant. Copyright © 2001 John Wiley & Sons, Ltd. [source] | ||||||||||