1,721,039 research outputs found
“Organic monocrystal-based FETs: electronical and structural studies” - PRESENTING AUTHOR
No full textDirhodium(II) carboxylates as building blocks. Macrocyclic dimers with vertically stacked Rh-2(4+) units
No full textReaction of Rh-2(OAc)(4) and H2L (=2,7-di- tert-butyl-9,9-dimethyl-4,5-xanthenedicarboxylic acid) in N,N-dimethylaniline gave the singly bridged dimer (AcO)(3)Rh2LRh2(OAc)(3) and three doubly bridged dimers, (AcO)(2)Rh2L2Rh2(OAc)(2), (HL)(AcO)Rh2L2Rh2(OAc)(2), and (HL)(AcO)Rh2L2Rh2(OAc)(HL). Crystal structures of the last two compounds showed a macrocyclic core with a trans arrangement of bridging dicarboxylates, with one or two of the four remaining acetate ligands replaced by a bridging ligand bound through one carboxylate only. The rhodium cages are separated by 4.5 Angstrom in the direction of the Rh-Rh axes, and offset horizontally by 2.5 Angstrom so that a rhodium atom of one cage lies over a carboxylate oxygen of the other, with Rh . . .O distances of 2.248-2.286 Angstrom
New high-nuclearity Ni-Pt carbonyl clusters: synthesis and X-ray structure of the ordered [Ni24Pt14(CO)44]4- and the substitutionally Ni/Pt disordered [Ni10(Ni6-xPtx)Pt8(CO)30]4- (x = 1.92) tetraanions
No full textThe reaction of [(NBu4)-Bu-n](2)[Ni-6(CO)(12)] in THF solution with 1.5-2 equivalents of K2PtCl4 leads to formation of the [Ni24Pt14(CO)(44)](4-) and [Ni-10(Ni6-xPtx)Pt-8(CO)(30)](4-) (x approximate to2) tetraanions, the latter presents a localised substitutional NY Pt disorder and an unprecedented close-packed metal structure
Molecular Fe, CO and Ni carbide carbonyl clusters and Nanoclusters†
Full text linkThe present minireview highlights the work of our group on Fe, Co and Ni carbide carbonyl clusters and nanoclusters, placing it in the context of the recent literature. After a brief introduction, Section 2 gives a short summary on the general features of molecular carbide carbonyl clusters. Then, specific examples of Fe, Co and Ni carbide carbonyl clusters are presented in the following three Sections. Each Section includes both homometallic and heterometallic clusters, as well as discussion of some of their most relevant chemical, electrochemical, structural and physical properties. General conclusions are outlined in Section 6
Organometallic reactions in aqueous media: Indium-promoted additions to 2-pyridyl and glyoxylic acid oxime ethers
No full textOxime ethers derived from 2-pyridinecarboxaldehyde and glyoxylic acid can be effectively allylated in water with five differently functionalized allylic bromides promoted by indium. When the metal is positioned in close proximity of flanking heteroatomic centers, chelation by In is indeed operative and affects both reactivity and stereochemistry. Stereochemical assignments in the addition products were based on X-ray crystallographic measurements and spectral correlations
Homoleptic Carbonyl Ni-Pd Clusters: Synthesis of [Ni16Pd16(CO)40]4- and [Ni26Pd20(CO)54]6- and Structural Characterization of [Nn Bu4]4[Ni16Pd16(CO)40]
No full textNi-decorated Pd frameworks are displayed by the anionic clusters [Ni16Pd16(CO)40]4- (1) and [Ni26Pd20(CO)54]6- (2) (left and right in the picture, respectively), which are stabilized by a shell of carbonyl ligands. The cluster anions were obtained by reaction of [Ni6(CO)12]2- with [Pd(SEt2)2Cl2] in THF
Acidochromism of donor-acceptor Stenhouse adducts in organic solvent
Full text linkFirst generation DASA derivatives can be reversibly isomerized from the coloured, open form to the colourless, closed isomer upon protonation, thus behaving as acidochromic compounds in halogenated organic solvent
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Heterometallic Ni-Pt Chini-Type Carbonyl Clusters: An Example of Molecular Random Alloy Clusters
Full text linkThe direct reactions of homometallic [Ni6(CO)12]2- and [Pt6(CO)12]2- Chini carbonyl clusters result in heterometallic Ni-Pt Chini-type clusters of the general formula [Pt6-xNix(CO)12]2- (x = 0-6). Their molecular structures have been determined by single-crystal X-ray diffraction (SC-XRD), showing a common octahedral (staggered, D3d) structure analogous to that of [Ni6(CO)12]2-, whereas [Pt6(CO)12]2- displays a trigonal-prismatic (eclipsed, D3h) structure. This structural change after replacing one single Pt with Ni may be classified as an alloying effect, and it has been theoretically investigated by DFT methods. Spectroscopic (IR and 195Pt and 13C NMR) and ESI-MS studies indicate that mixtures of [Pt6-xNix(CO)12]2- (x = 0-6) clusters are actually present in solution, whose compositions may be varied in an almost continuous way. Thus, they may be viewed as random alloy clusters whose overall compositions depend on the stoichiometry of the reagents
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