One-Dimensional Mercury Telluride Polymers: Synthesis and Structure of (Et₄N)₂Hg₂Te₄ and (Me₄N)₄Hg₃Te₇·(0.5en)

Two new one-dimensional mercury telluride polymers have been synthesized and structurally characterized by single crystal X-ray diffraction. Treatment of an ethylenediamine (en) extract of an alloy of nominal composition K₂Hg₂Te₃ with Et₄NI gives a 40% yield of (Et₄N)_2⁻Hg₂Te₄ (1). Dark hexagonal plates of (1) crystallize in the monoclinic space group P2₁/a with a = 14.869(8), b = 12.263(4), c = 15.297.6(6) Å, β = 97.43(4)°, Z = 4 and R(R_w) = 0.057(0.069). The Hg₂Te₄²⁻ chains in (1) are built up from five-membered {Hg₂Te₃} rings with the trigonally planar coordinated Hg atoms in the 1 and 3 positions of the ring. These rings are bonded into strings by Te atoms. Mercury telluride (Me₄N)₃Hg₃Te₇·(0.5en) (2) is prepared by the constant current cathodic dissolution of a Hg₂Te₃ electrode into an en solution of Me₄NI. Flat, black needles of (2), crystallize in the triclinic space group P1 with a = 12.080(3), b = 17.261(7), c = 9.905(1) Å, α = 94.22(3)°, β = 92.26(1)°, γ = 80.12(3)°, V = 2028.2(9) ų, Z = 2 and R(R_w) = 0.041(0.038). Telluride 2 contains five-membered rings similar to those found in 1 with the exception that the five-membered rings are fused at a common tetrahedrally coordinated spiro Hg atom. These Hg₃Te₆ moieties, with two Hg possessing approximately trigonal-planar coordination and one with tetrahedral coordination are connected into one-dimensional strands via additional single Te atom bridges.