Synthesis,Characterization and Magnetic Properties of a New Manganese(II) Phosphite

A new manganese(II) phosphite, Mn₂F₂(HPO₃)(1), was synthesized with tetraethylene pentamine as structure directing agent under hydrothermal conditions. The as-synthesized product was characterized by single crystal X-ray diffraction, powder X-ray diffraction, infrared(IR), UV-Vis spectrum, thermogravimetric analysis(TGA), inductive coupled plasma-atomic emission spectroscopy(ICP-AES), elemental analyses and magnetic susceptibility measurement. Single crystal X-ray diffraction analysis reveals that compound 1 crystallized in the orthorhombic space group Pnma, with a=0.75667(15) nm, b=1.0247(2) nm, c=0.55432(11) nm, V=0.42980(15) nm³, Z=4. The 3D compact framework of compound 1 was built up by the Mn₂O₆F₄ dimers and HPO₃ pseudo-pyramids. Compound 1, a new metal-rich manganese phosphite, shows a high thermal stability limit of 550℃. Magnetic measurement indicates that compound 1 exhibits the global antiferromagnetic interactions with a ferromagnetic transition at 28 K.