Divalent-metal-stabilized aluminophosphates exhibiting a new zeolite framework topology

Two divalent-metal-containing aluminophosphates, (C ₅H ₁₄N ₂)[Co ₂Al ₄P ₆O ₂₄] and (C ₅H ₁₄N ₂)[Zn ₂Al ₄P ₆O ₂₄] (denoted as MAPO-CJ62; M = Co, Zn), have been hydrothermally synthesized by using N-methylpiperazine as the structure directing agent. Their structures are determined by single crystal X-ray diffraction and further characterized by powder X-ray diffraction, inductively coupled plasma, and thermogravimetric and diffuse reflectance spectroscopy analyses. Both of these two compounds exhibit a new zeolite framework topology. This new zeolite framework contains 1-dimensional 8-ring channels running along the [010] direction. All the metal and P atoms are tetrahedrally coordinated and alternately connected to each other through bridging O atoms. Inductively coupled plasma analysis shows that the molar ratio of M:Al in MAPO-CJ62 is 1:2. The M ²⁺ ions in MAPO-CJ62 selectively occupy two of the three possible crystallographically distinct positions. A pure aluminophosphate analogue of MAPO-CJ62 without M ²⁺-incorporation, denoted as AlPO-CJ62, has not been obtained in our experiment so far. The necessity of introducing M ²⁺ ions and their ordered distribution in MAPO-CJ62 has been elucidated by analyzing the distortions of Al-centered tetrahedra in the hypothetical framework of AlPO-CJ62.