Ionothermal synthesis of a new open-framework manganese(II) diphosphate

A novel open-framework manganese diphosphate compound, [NH3(CH2)2NH3][MnP2O7], denoted as JIS-13 (Jilin Ionothermal Synthesis-13), has been ionothermally synthesized by using a eutectic mixture of tetramethylammonium chloride and 2-imidazolidone as the solvent and template-delivery agent, which in situ yields ethylene diammonium cations (en2+) as the template. The structure of JIS-13 is determined by single-crystal X-ray diffraction and further characterized by powder X-ray diffraction (PXRD), inductively coupled plasma (ICP), thermogravimetric (TG), elemental analyses, X-ray photoelectron spectroscopy (XPS) and magnetic measurements. The alternation of MnO5 trigonal bipyramids and P2O7 units linking through their vertices forms the three-dimensional (3-D) open framework of JIS-13, which comprises 12-ring channels along the [100] direction. Protonated en2+ cations act as the templates to compensate the negative charges of the inorganic framework. Magnetic measurements reveal that weak antiferromagnetic interaction exists in JIS-13.