Browsing by Author "Flandrois, Serge"

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    Doped dialkylated phenazines : a novel series of highly conducting organic solids
    (1981) Dietz, Klaus; Flandrois, Serge; Keller, Heimo J.; Koch, P.; Queckbörner, Jobst G.; Schweitzer, Dieter
    Doping dimethylphenazine (M2P)-TCNQ and diethylphenazine (E2P)-TCNQ with phenazine gave rise to new conducting compounds with segregated stacks : (M2P)0.5 (P)0,5 TCNQ and (E2P)0,55 (P)0,45 TCNQ. The room temperature electrical conductivities are in the range 10-100 Ω-1 cm-1 for (1) and 1-10 Ω-1cm-1 for (2). The paramagnetism of both compounds could be separated into contributions from TCNQ and Phenazine stacks. The structural electrical and magnetic similarities of (1) with the well-known N-methylphenazinium (NMP)-TCNQ led to a reexamination of its magnetic properties. It was shown that an estimate of the charge transfer can be obtained from the temperature dependence of the magnetic susceptibility.
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    A novel molecular metal: (oxamide oximato)(oxamide oxime)nickel(II) tetracyanoquinodimethanide, [Ni(oaoH)(oaoH2)]tcnq, and physical properties of its semiconducting Pt analogue
    (1985) Endres, Helmut; Bongart, August; Nöthe, Dietrich; Hennig, Ingolf; Schweitzer, Dieter; Schäfer, Herbert; Helberg, Hans W.; Flandrois, Serge
    (C4H11N8NiO4)+(C12H4N4)-, Mr = 498.09 is triclinic, p1, a -=3.7718(6), b = 7.436(2), c =17.511(4) A, a=88.67(2), β=86.93(2), γ=85.05(2), γ= 488.51 A 3, Z = 1, d c=1.69 gcm -3, final R w= 0.035 for 1454 observed independent reflections. The crystals consist of segregated regular parallel stacks of planar metal complex cations and tcnq - counterions with intermolecular H bonds stabilizing the structure. The compound is metallic at room temperature. A metal to semiconductor transition around 230 K shows up in thermopower data, in the microwave conductivity and epr around 170 K. It is not visible in the static magnetic susceptibility.