Synthesis, crystal structure and thermochemical study on a novel ternary coordination compound [Bi(C7H5O3)3C12H8N2]

A new ternary bismuth complex [Bi(C7H5O3)3C12H8N2] (C7H6O3, o-hydroxybenzoic acid; C12H8N2, 1,10-phenanthroline monohydrate) and its crystal were prepared and characterized. The results showed that the crystal is triclinic, space group P ī with a = 10.184(2) A, b = 11.807(2) A, c = 12.893(3) A, α = 76.81(3)°, β = 68.79(3)°, γ = 80.85(3)°, Z = 2, Dc = 1.891 g cm−3, F(000) = 776. The crystal contains a mononuclear molecule. Bi3+ is eight-coordinated by three bidentate chelating carboxylic groups and one o-phenanthroline molecule; C7H6O3 coordinated with Bi3+ in the form of carboxylate; the two nitrogen atoms of C12H8N2 are bidentate-coordinated with Bi3+ forming a chelate ring. At 298.15 K, the standard molar enthalpy of formation of the title complex was estimated to be Δ f H m Θ [Bi(C7H5O3)3C12H8N2 (s), 298.15 K] = −(303.99 ± 4.95) kJ mol−1.