The title compound C28H17F4N6, Mr=513.48, crystallizes in the monoclinic space group P21/c, with a=10.972(2) Å, b=17.557(3) Å, c=13.523(4) Å, β=111.88(2)°, V=2417.36 Å3, z=4, and dc=1.411 Mg m−3. Final refinement yielded residuals of R=0.056 and Rw=0.046. The structure consists of (NBP+)2 and (TCNQF−4)2 dimers stacked in a DDAA sequence along the c axis. The NBP+ and TCNQF−4 ions are planar, with interplanar distances of 3.54(2) Å for a donor pair and 3.15(3) Å for an acceptor pair. The angle between the NBP+ and TCNQF−4 planes is 15.8°. In the ESR experiments, two equivalent species of thermally activated Frenkel triplet spin excitons (TSE), with differently oriented fine structure tensors, are observed. They are located on two TCNQF4 molecular pairs of different orientation. A motion of the TSE in the b direction can be excluded. Additional S=1/2 lines are due to immobile doublet spins on TCNQF−4 radical ions.

Temperature dependent dc and microwave conjuctivity data together with EPR and optical reflectance measurements on the~mixedHsystem (pe)2(AsF 6)0,75(PF 6)0,35 x 0,85 CH 2 C1 2 are described. The data prove metallic behaviour of this organic solid down to 200 K.

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The title compound C28H21N6, Mr=441.51 crystallizes in the triclinic space group P1̄, with lattice constants a=831.5(3), b=965.7(5), c=1638.3(8) pm, α=70.54(3)°, β=71.51(3)°, γ=76.78(3)°, V=1.165(1) nm3, Z=2, dc=1.258 Mg m−3. Final refinement yielded residuals R=0.050 and Rw=0.065. The structure consists of (NBP+)2 π-bonded dimers and (TCNQ−)2 π-bonded dimers that alternate along the [101] direction. The structure of NBP TCNQ thus is very similar to that of NBP TCNQF4 (where TCNQF4 is the 2,3,5,6-tetrafluoro derivative of TCNQ) but the latter salt belongs to the space group P21/c. The NBP+ and TCNQ− ions are planar, with interplanar distances of 344(2) pm for the donor pair, and 316(3) pm for the acceptor pair. The angle between the NBP+ and the TCNQ− planes is 5.9°. In the ESR experiments a single thermally activated ‘‘quasi-immobile’’ Frenkel triplet spin exciton (TSE) is seen, along with the usual g=2 impurity line and a second set of narrower g=2 lines that are probably due to exchange-narrowed TCNQ− radicals. The thermal activation energy for the S=1 spectrum is Ea=0.13 eV. The ESR fine structure tensor orientations and fine structure constants D/hc=±0.013 09(5) and E/hc=∓0.002 0(2) cm−1 are consistent with a model calculation using a triplet (TCNQ−)2 supermolecular state.

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