Crystal structure of cyclo-tris­(μ-3,4,5,6-tetra­fluoro-o-phenyl­ene-κ(2) C (1):C (2))trimercury–tetra­cyano­ethyl­ene (1/1)

The title compound, [Hg(3)(C(6)F(4))(3)]·C(6)N(4), contains one mol­ecule of tetra­cyano­ethyl­ene B per one mol­ecule of mercury macrocycle A, i.e., A•B, and crystallizes in the monoclinic space group C2/c. Macrocycle A and mol­ecule B both occupy special positions on a twofold rotation axis and the inversion centre, respectively. The supra­molecular unit [A•B] is built by the simultaneous coordination of one of the nitrile N atoms of B to the three mercury atoms of the macrocycle A. The Hg⋯N distances range from 2.990 (4) to 3.030 (4) Å and are very close to those observed in the related adducts of the macrocycle A with other nitrile derivatives. The mol­ecule of B is almost perpendicular to the mean plane of the macrocycle A at the dihedral angle of 88.20 (5)°. The donor–acceptor Hg⋯N inter­actions do not affect the C N bond lengths [1.136 (6) and 1.140 (6) Å]. The trans nitrile group of B coordinates to another macrocycle A, forming an infinite mixed-stack [A•B](∞) architecture toward [101]. The remaining N atoms of two nitrile groups of B are not engaged in any donor–acceptor inter­actions. In the crystal, the mixed stacks are held together by inter­molecular C—F⋯C N secondary inter­actions [2.846 (5)–2.925 (5) Å].