Structure of the Charge-Transfer Salt 2,2′,5,5′-Tetraselenafulvalene-7,7,8,8-Tetracyano-p-quinodimethane (TSeF-TCNQ)

Abstract

2,2′,5,5′-Tetraselenafulvalene-7,7,8,8-tetracyano-p- quinodimethane (1/1), TSeF-TCNQ, C6H4Se4.C12H4N 4, Mr = 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 Å3, T = 297 K, Z = 2, F(000) = 560, Dx = 2.28 Mgm-3, λ(CuKα) = 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.