1D chlorine bridged mercury(II) complex containing nitronyl nitroxide radicals: Synthesis, crystal structures, and magnetic properties

A novel 1D chlorine bridged mercury(II) complex containing nitronyl nitroxide radicals, [Hg₂(NIT-1′-MeBzIm)Cl₄] _n (NIT-1′-MeBzIm = 2-{2′-[(1′-methyl)benzimidazolyl]}-4,4,5,5-tetrameth-ylimidazoline-1-oxyl-3-oxide), has been prepared and characterized by magnetic and single-crystal X-ray diffraction studies. The complex crystallizes in triclinic, space group P $bar 1$ , Z = 2. Crystal data: C₁₅H₁₉C₁₄Hg₂N₄O₂, M = 830.32, a = 7.4454(16), b = 9.463(2), c = 16.180(3) Å, α = 94.245(2)°, β = 100.747(2)°, γ = 102.523(2)°, V = 1085.5(4) ų, ρ _c = 2.540 g/cm³, μ(MoK_α) = 14.636 mm^?1, F(000) = 762, R = 0.0312 and wR = 0.0779 for 3990 observed reflections with I > 2σ(I). The X-ray analysis reveals that the Hg²⁺ ions shows two coordination geometries of five-coordinated with a distorted square pyramidal coordination geometry and quadrilateral geometry. The units of [Hg₂(NIT-1′-MeBzIm)C_l4] _n were connected as 1D chain structure by the chlorine bridges. Magnetic investigation indicates the existence of weak intramolecular interactions is antiferromagnetic with J = ?1.23 cm^?1, where the spin Hamitonian is defined as H = $ - 2sumnolimits_{i,j} {J_{i,j} S_i S} $ within the complex.