Their Potential (their + potential)

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Terms modified by Their Potential

  • their potential application

  • Selected Abstracts

    Calculated Enthalpies for Dimerisation of Binary, Unsaturated, Main-Group Element Hydrides as a Means to Analyse Their Potential for Multiple Bonding

    Hans-Jörg Himmel
    Abstract Herein, the dimerisation of subvalent, binary, main-group element hydrides with the potential for multiple bonding is studied using both hybrid DFT (B3LYP) and ab initio [MP2 and CCSD(T)] methods. The [2+2] cycloaddition is an important and characteristic reaction of derivatives of ethylene. A comparison of dimerisation reactions for several compounds with the potential for multiple bonding should, therefore, shed light on the properties of these species. Our study includes the hydrides E2H2 (E = B, Al, Ga, N P or As), E2H4 (E = C, Si or Ge) and ENH4 (E = B, Al or Ga) and their dimers. Several isomeric forms of the monomers and dimers have to be considered. The trends within a group and a period are established and the factors responsible for them are discussed. It turns out that, generally, the enthalpies for dimerisation increase for heavier homologues, reflecting that the most important factor is the reduced strength of the E,E bonds in the monomers prior to dimerisation and, to some degree, also the reduced ring strain in the cyclic dimers. The exceptions are the dimerisations of B2H2 and Al2H2, both of which lead to the tetrahedral E4H4 species (E = B or Al). Dimerisation of Al2H2 is associated with a smaller enthalpy than that for the dimerisation of B2H2. Comparisons and analyses are made complicated because of the changes in the structures of the isomeric global minima between homologues. (© Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2003) [source]

    Strong Luminescent Iridium Complexes with C,N=N Structure in Ligands and Their Potential in Efficient and Thermally Stable Phosphorescent OLEDs,

    ADVANCED MATERIALS, Issue 3 2009
    Bao Xiu Mi
    Homoleptic iridium complexes with C,N=N type ligands, i.e., 1,4-bis (phenyl) phthalazine (BPPa) and 3,6-bis(phenyl)pyridazine (BPPya), are strong phosphorescents, easy to synthesize, and thermally stable, thus having great potential in optical electronic applications, as demonstrated in Ir(BPPa)3 -based OLED devices. A quantum chemistry study shows that C,N=;N type ligands can bond to Ir more strongly. [source]

    Calculated Enthalpies for Dimerization of Binary, Unsaturated, Main-Group Element Hydrides as a Means to Analyse Their Potential for Multiple Bonding.

    CHEMINFORM, Issue 31 2003
    Hans-Joerg Himmel
    No abstract is available for this article. [source]

    In Situ Synthesis of Trisubstituted Methanol Ligands and Their Potential as One-Pot Generators of Cubane-like Metal Complexes

    Brendan F. Abrahams Dr.
    Abstract Two different one pot routes to a variety of metal cubane compounds are reported; one route is based on an in situ benzilic acid type rearrangement and the other involves in situ nucleophilic attack at a ketone. Diketosuccinic acid in basic solution in the presence of certain divalent metal ions undergoes a benzilic acid type rearrangement to generate the carbon oxyanion, C(CO2,)3O,, which serves as a cubane-forming bridging ligand in a series of octanuclear complexes of composition [M8{C(CO2)3O}4](H2O)12 (M=Mg, Mn, Fe, Co, Ni, Zn). At the heart of each of these highly symmetrical aggregates is an M4O4 cubane core, each oxygen component of which is provided by the alkoxo centre of a C(CO2,)3O, ligand. Reaction of 2,2,-pyridil, (2-C5H4N)COCO(2-C5H4N), and calcium nitrate in basic alcoholic solution, which proceeds by a similar benzilic acid type rearrangement, gives the cubane compounds, [Ca4L4(NO3)4] in which L=(2-C5H4N)2C(COOR)O, (R=Me or Et). Nucleophilic attack by bisulfite ion at the carbonyl carbon atom of 2,2,-dipyridyl ketone in the presence of certain divalent metals generates the electrically neutral complexes, [{(C5H4N)2SO3C(OH)}2M] (M=Mn, Fe, Co, Ni, Zn and Cd). Cubane-like complexes [M4{(C5H4N)2SO3C(O)}4] (M=Zn, Mn) can be obtained directly from 2,2,-dipyridyl ketone in one-pot reaction systems (sealed tube, 120,°C) if a base as weak as acetate ion is present to deprotonate the OH group of the initial [(C5H4N)2SO3C(OH)], bisulfite addition compound; the [(C5H4N)2SO3C(O)]2, ligand in this case plays the same cubane-forming role as the ligands C(COO,)3O, and (2-C5H4N)2C(COOR)O, above. When excess sodium sulfite is used in similar one-pot reaction mixtures, the monoanionic complexes, [M3Na{(C5H4N)2SO3C(O)}4], (M=Zn, Mn, Co) with an M3NaO4 cubane core, are formed directly from 2,2,-dipyridyl ketone. [source]