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Cluster Compounds (cluster + compound)
Selected AbstractsReactivity of InCp* Towards Transition Metal Carbonyl Clusters: Synthesis and Structural Characterization of the Rh6(CO)16,x(InCp*)x Mixed-Metal Cluster Compounds, x = 1,2EUROPEAN JOURNAL OF INORGANIC CHEMISTRY, Issue 22 2007Elena V. Grachova Abstract With [Rh6(CO)15(InCp*)], the first example of a transition metal carbonyl cluster with a coordinated InCp* (Cp* = C5Me5) fragment in the ligand environment is reported. This cluster with direct Rh,In bonds forms in the reaction of the hexanuclear carbonyl rhodium cluster Rh6(CO)15(NCMe) with InCp* under mild conditions. This is characterized by means of IR and NMR spectroscopy and crystal structure analysis. (© Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2007) [source] Reversible Bromide,Chloride Exchange in Zirconium Cluster Compounds: Synthesis by Means of Ionic Liquids, Structures, and Some Spectral Data of (EMlm)4[(Zr6Z)Br18] Cluster Phases (Z = Be, Fe).CHEMINFORM, Issue 39 2007Johannes B. Willems 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] ChemInform Abstract: Ring, Chain, and Cluster Compounds in the Cl,Ga,N,H System.CHEMINFORM, Issue 21 2002Alexey Y. Timoshkin Abstract ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 100 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] Applications of gold cluster compounds in immunocytochemistry and correlative microscopy: comparison with colloidal goldJOURNAL OF MICROSCOPY, Issue 3 2000J. M. Robinson In this review, we discuss the immunocytochemical literature with respect to a comparison between conventional colloidal gold and gold cluster compounds as immunoprobes. The relative advantages and disadvantages of each of these types of particle for immunocytochemical applications are discussed. We present results from our own laboratories and those of others on the comparison of these immunoprobes in selected experimental situations. These results show the use of gold cluster compounds at both light and electron microscope levels. At the ultrastructural level, gold cluster compounds have been used in pre-embedding labelling of cultured cells, and for labelling of ultrathin cryosections and freeze-fracture preparations. Recently, fluorescently tagged gold cluster compounds have become available. Using ultrathin cryosections of human neutrophils as a model system, we demonstrate that a single immunoprobe (i.e. a fluorescently tagged gold cluster compound) is a robust probe for correlative fluorescence and electron microscopy. [source] Two Metalloid Ga22 Clusters Containing a Novel Ga22 Core with an Icosahedral Ga12 CenterCHEMISTRY - A EUROPEAN JOURNAL, Issue 8 2004Andreas Schnepf Dr. Abstract In addition to the two so far known types of metalloid Ga22 clusters a new type is presented in two compounds containing the anions [Ga22Br{N(SiMe3)2}10Br10]3, (1) and [Ga22Br2{N(SiMe3)2}10Br10]2, (2). In both anions 10 Ga atoms of the icosahedral Ga12 core are directly connected to further Ga atoms. The two remaining Ga atoms (top and bottom) of the Ga12 icosahedron are bonded to one (1) and two Br atoms (2), respectively. The formation and structure of both compounds containing a slightly different average oxidation number of the Ga atoms is discussed and compared especially with regard to the Ga84 cluster compound and similar metalloid Aln clusters. Finally, the consequences arising from the presence of two very similar but not identical Ga22 cluster compounds are discussed and special consideration is given to the so far not understood physical properties (metallic conductivity and superconductivity) of the Ga84 cluster compound. Zusätzlich zu den kürzlich vorgestellten zwei Typen von metalloiden Ga22 -Clustern wird eine neue Variante der Anordnung von 22 Ga-Atomen durch zwei Verbindungen präsentiert, die die Anionen [Ga22Br{N(SiMe3)2}10Br10]3,1 und [Ga22Br2{N(SiMe3)2}10Br10]2,2 enthalten. In beiden Anionen sind 10 Ga-Atome des zentralen ikosaedrischen Ga12 -Zentrums direkt an weitere Ga-Atome gebunden. Die zwei verbleibenden Ga-Atome an der Spitze und am Fuß des Ikosaeders sind direkt mit einem (1) beziehungsweise zwei (2) Br-Atomen verknüpft. Die Bildung und die Struktur beider Verbindungen, die eine leicht unterschiedliche mittlere Oxidationszahl der Ga-Atome enthalten, wird im Hinblick auf die Ga84Clusterverbindung und im Vergleich zu den Verhältnissen in ähnlichen metalloiden Al-Verbindungen diskutiert. Schließlich werden die Konsequenzen des nicht trivialen Nachweises der zwei sehr ähnlichen aber nicht identischen Ga22 -Cluster 1 und 2 diskutiert, die mögliche Ansatzpunkte für die Deutung bisher nicht verstandener physikalischer Eigenschaften (metallische Leitfähigkeit und Superleitfähigkeit) der Ga84Clusterverbindung liefern. [source] Synthesis and Structure of [nPr3N(CH2)6NnPr3][CuFe3Br3(SePh)6], [Cu5Fe(SePh)7(PPh3)4] and [Cu4Fe3(SePh)10(PPh3)4],EUROPEAN JOURNAL OF INORGANIC CHEMISTRY, Issue 1 2007Andreas Eichhöfer Abstract CuBr and Fe(OOCCH3)2 react with PhSeSiMe3 in acetonitrile in the presence of the diammonium salt [nPr3N(CH2)6NnPr3]Br2 to yield ionic [nPr3N(CH2)6NnPr3][CuFe3Br3(SePh)6]. The neutral complexes [Cu5Fe(SePh)7(PPh3)4] and [Cu4Fe3(SePh)10(PPh3)4] were obtained by similar reactions of different stoichiometric mixtures of CuOOCCH3 and FeCl2 with PPh3 and PhSeSiMe3. The crystal structures of the compounds were determined by single-crystal X-ray analysis to give new structural types of molecular cluster compounds formed by copper, iron and selenium. Thermal treatment of [Cu5Fe(SePh)7(PPh3)4] and [Cu4Fe3(SePh)10(PPh3)4] resultsin the formation of mixtures of binary Cu2Se and ternaryCuFeSe2.(© Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2007) [source] [Re6Q7O(3,5-Me2PzH)6]Br2·3,5-Me2PzH (Q = S, Se) , New Octahedral Rhenium Cluster Complexes with Organic Ligands: Original Synthetic Approach and Unexpected Ligand Exchange in the Cluster CoreEUROPEAN JOURNAL OF INORGANIC CHEMISTRY, Issue 4 2005Yuri V. Mironov Abstract Two new octahedral rhenium cluster complexes, [Re6S7O(3,5-Me2PzH)6]Br2·3,5-Me2PzH (1) and [Re6Se7O(3,5-Me2PzH)6]Br2·3,5-Me2PzH (2), with the organic ligand 3,5-dimethylpyrazole (3,5-Me2PzH), have been synthesised by reaction of rhenium chalcobromides Cs3[Re6(µ3 -Q7Br)Br6] (Q = S, Se) with molten dimethylpyrazole. During the reaction, all six apical bromine ligands of the cluster complexes are substituted by the organic ligand, which is coordinated through the aromatic nitrogen atom N2. Additionally, the inner ligand µ3 -Br in the cluster core [Re6(µ3 -Q7Br)]3+ is substituted by oxygen, giving cluster cores [Re6(µ3 -Q7O)]2+ with mixed chalcogen/oxygen ligands. Compounds 1 and 2 have been characterised by single-crystal X-ray diffraction analysis. They are isostructural and crystallise with four formula units in the unit cell. Absorption spectra and luminescence characteristics of these two cluster compounds have been investigated in methanol. Absorption starts below 400 nm. For both compounds, broad emissions were found. The fluorescence decays of the two compounds follow a diexponential decay behaviour. The main fluorescence intensity decays have longer fluorescence lifetimes of 3.07 ± 0.03 (1) and 3.96 ± 0.02 µs (2). Studying the thermal stability of both compounds in vacuo showed that the release of 3,5-dimethylpyrazole ligands begins near 200 °C, and decomposition, with the removal of 7 molecules of 3,5-Me2PzH, is complete at 330 °C. (© Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2005) [source] Metal Chalcogenide Clusters on the Border between Molecules and Materials,ADVANCED MATERIALS, Issue 18 2009John F. Corrigan Abstract The preparative and materials chemistry of high nuclearity transition metal chalcogenide nanoclusters has been in the focus of our research for many years. These polynuclear metal compounds possess rich photophysical properties and can be understood as intermediates between mononuclear complexes and binary bulk phases. Based on our previous results we discuss herein recent advances in three different areas of cluster research. In the field of copper selenide clusters we present the synthesis of monodisperse, nanostructured , -Cu2Se via the thermolysis of well-defined cluster compounds as well as our approaches in the synthesis of functionalized clusters. In case of silver chalcogenides we established a strategy to synthesis cluster compounds containing several hundreds of silver atoms with the nanoclusters arranging in a closely packed crystal lattice. Finally the presented chalcogenide clusters of the group 12 metals (Zn, Cd, Hg) can be taken as model compounds for corresponding nanoparticles as even the smallest of frameworks display a clear structural relationship to the bulk materials. [source] Applications of gold cluster compounds in immunocytochemistry and correlative microscopy: comparison with colloidal goldJOURNAL OF MICROSCOPY, Issue 3 2000J. M. Robinson In this review, we discuss the immunocytochemical literature with respect to a comparison between conventional colloidal gold and gold cluster compounds as immunoprobes. The relative advantages and disadvantages of each of these types of particle for immunocytochemical applications are discussed. We present results from our own laboratories and those of others on the comparison of these immunoprobes in selected experimental situations. These results show the use of gold cluster compounds at both light and electron microscope levels. At the ultrastructural level, gold cluster compounds have been used in pre-embedding labelling of cultured cells, and for labelling of ultrathin cryosections and freeze-fracture preparations. Recently, fluorescently tagged gold cluster compounds have become available. Using ultrathin cryosections of human neutrophils as a model system, we demonstrate that a single immunoprobe (i.e. a fluorescently tagged gold cluster compound) is a robust probe for correlative fluorescence and electron microscopy. [source] From "Parasitic" Association Reactions toward the Stoichiometry Controlled Gas Phase Synthesis of Nanoparticles: A Theoretically Driven Challenge for ExperimentalistsTHE CHEMICAL RECORD, Issue 5 2002Alexey Y. Timoshkin Abstract In the present record a model for the gas-phase reactions during the chemical vapor deposition (CVD) processes of group 13,15 materials is presented, based on the results of extensive quantum-chemical modeling. Thermodynamic criteria have been introduced to evaluate the importance of a range of association reactions. For the organometallic and hydride derivatives, association processes are found to be favorable both thermodynamically and kinetically. Formation of high mass association products takes place under CVD conditions, including laser-assisted CVD. Structural and thermodynamic properties of the most important ring and cluster intermediates have been predicted. The stoichiometry-controlled synthesis of the 13,15 ternary alloys and nanoparticles using cluster compounds as single-source precursors is predicted to be viable. The association pathway described may be generalized to the CVD reactions of many binary materials (12,16, 13,16, 13,15, 14,15, 14,16). © 2002 The Japan Chemical Journal Forum and Wiley Periodicals, Inc. Chem Rec 2: 319,338, 2002: Published online in Wiley InterScience (www.interscience.wiley.com) DOI 10.1002/tcr.10037 [source] Two Metalloid Ga22 Clusters Containing a Novel Ga22 Core with an Icosahedral Ga12 CenterCHEMISTRY - A EUROPEAN JOURNAL, Issue 8 2004Andreas Schnepf Dr. Abstract In addition to the two so far known types of metalloid Ga22 clusters a new type is presented in two compounds containing the anions [Ga22Br{N(SiMe3)2}10Br10]3, (1) and [Ga22Br2{N(SiMe3)2}10Br10]2, (2). In both anions 10 Ga atoms of the icosahedral Ga12 core are directly connected to further Ga atoms. The two remaining Ga atoms (top and bottom) of the Ga12 icosahedron are bonded to one (1) and two Br atoms (2), respectively. The formation and structure of both compounds containing a slightly different average oxidation number of the Ga atoms is discussed and compared especially with regard to the Ga84 cluster compound and similar metalloid Aln clusters. Finally, the consequences arising from the presence of two very similar but not identical Ga22 cluster compounds are discussed and special consideration is given to the so far not understood physical properties (metallic conductivity and superconductivity) of the Ga84 cluster compound. Zusätzlich zu den kürzlich vorgestellten zwei Typen von metalloiden Ga22 -Clustern wird eine neue Variante der Anordnung von 22 Ga-Atomen durch zwei Verbindungen präsentiert, die die Anionen [Ga22Br{N(SiMe3)2}10Br10]3,1 und [Ga22Br2{N(SiMe3)2}10Br10]2,2 enthalten. In beiden Anionen sind 10 Ga-Atome des zentralen ikosaedrischen Ga12 -Zentrums direkt an weitere Ga-Atome gebunden. Die zwei verbleibenden Ga-Atome an der Spitze und am Fuß des Ikosaeders sind direkt mit einem (1) beziehungsweise zwei (2) Br-Atomen verknüpft. Die Bildung und die Struktur beider Verbindungen, die eine leicht unterschiedliche mittlere Oxidationszahl der Ga-Atome enthalten, wird im Hinblick auf die Ga84Clusterverbindung und im Vergleich zu den Verhältnissen in ähnlichen metalloiden Al-Verbindungen diskutiert. Schließlich werden die Konsequenzen des nicht trivialen Nachweises der zwei sehr ähnlichen aber nicht identischen Ga22 -Cluster 1 und 2 diskutiert, die mögliche Ansatzpunkte für die Deutung bisher nicht verstandener physikalischer Eigenschaften (metallische Leitfähigkeit und Superleitfähigkeit) der Ga84Clusterverbindung liefern. [source] P NMR studies on the ligand dissociation of trinuclear molybdenum cluster compoundsCHINESE JOURNAL OF CHEMISTRY, Issue 9 2003Zhao-Ji Li Abstract A series of carboxylate-substituted trinuclear molybdenum cluster compounds formulated as Mo3S4(DTP)3(RCO2)(L), where R = H, CH3, C2H5, CH2Cl, CCl3, R1C6H4(R1 is the group on the benzene ring of aromatic carboxylate), L = pyridine, CH3CN, DMF, have been synthesized by the ligand substitution reaction. The dissociation of the loosely-coordinated ligand L from the cluster core was studied by 31P NMR. The dissociation process of L is related to the solvent, temperature, and acidity of carboxylate groups, so as to affect the solution structure and reactive properties of the cluster. The long-distance interaction between ligands RCO2 and L is transported by Mo3S4 core. [source] | ||||||||||