Crystal structure and thermal decomposition mechanism of [Mn(SCZ) ₃](PA)₂·H₂O

A new coordination compound [Mn(SCZ)₃](PA)₂ H ₂O has been obtained, and its molecular structure was characterized by using X-ray single-crystal diffraction, elemental analysis and FT-IR technique. The crystal belongs to triclinic, space group P1 with a = 0.7991(2), b = 1.2968(3), c = 1.4791(2) nm, α = 72.78(1), β = 84.36(1), γ = 81.80(2)°, C₁₅H₂₁N₁₅O₁₈Mn, V = 1.4465(5) nm³, Z = 2, D_c = 1.732 g/cm³, M _r = 754.41, F(000) = 770, S = 1.037 and μ(MoKα) = 0.565 mm^-1. The final R and wR are 0.0634 and 0.1292, respectively for 3812 observed reflections with I>2σ(I). The Mn²⁺ is six-coordinated, and SCZ acts as the bidentate ligand. Mn²⁺ coordinates to the oxygen and nitrogen atoms of three SCZ molecules to form three stable five-membered rings. The PA anions and coordination cations are bonded together by electrostatic attraction and hydrogen bonds, and the complicated three-dimensional net structure is constructed, which strongly enhances the stability of the coordination compound. The thermal decomposition processes of [Mn(SCZ)₃](PA)₂ H₂O contain two intensive exothermic stages, and the exothermic temperature is higher than 200°C. The final decomposed residue is MnO.