Structure of the charge-transfer salt 2,2',5,5'-tetraselenafulvalene–7,7,8,8-tetracyano-p-quinodimethane (TSeF–TCNQ)

2,2′,5,5′-Tetraselenafulvalene-7,7,8,8-tetracyano-p-quinodimethane (1/1), TSeF–TCNQ, C₆H₄Se₄.C₁₂H₄N₄, M_r = 596.13, monoclinic, P2₁/c, a = 12.5048 (4), b = 3.8724 (2), c = 18.5041 (7) Å, β = 104.131 (3)°, V = 868.9 ų, T = 297 K, Z = 2, F(000) = 560, D_x = 2.28 Mg m⁻³, λ(Cu Kα) = 1.5418 Å, μ = 115.7 cm⁻¹, R(F) = 0.018, wR(F) = 0.030 for 1393 unique reflections with σ(F²) > 3F². The crystals are isostructural with the corresponding tetrathiafulvalene salt, TTF–TCNQ, with both cations and anions arranged in segregated stacks parallel to b. There are Se...N distances of 3.17 and 3.18 Å, along a, between cation and anion stacks, and H...H distances of 2.58 Å, along c, between neighboring cation stacks, all shorter than the corresponding distances in TTF–TCNQ.

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